Die Schwalbe

101 problem(s) found in 3878 milliseconds (displaying 100 problem(s)). [COMMENTDATE>=20200919 AND NOT K='Hilfsrückzüger' AND NOT S='Scobs lignea' AND K='Valladao-Task'] [download as LaTeX]

1 - P0000058
Leonid M. Borodatow
5758v Die Schwalbe 103 02/1987
P0000058
(13+9) C+
h#3
b) sBa6 statt sLa6
a) 1. ... exf6ep 2. 0-0-0 Lxf4 3. Td7 a8=D#
b) 1. ... Kxf4 2. Te7 e6 3. Tb8 axb8=D,T#
play all play one stop play next play all
Anton Baumann: Mattdual in b): 3.Tb8 axb8=D,T# (2022-12-16)
A.Buchanan: So Borodatow got it all working! In a) Black might have captured hxgxf and axPb. So castling rights might still be maintained with the ep. In b) on the other hand, it must be axb, bxa, exf and wPgxh6, so there was the cage. Promotion to TD is tolerated in the final move, although it may not be puristic, without the convention, too many mates would be excluded (2022-12-16)
comment
Keywords: En passant as key, Castling (sg), Cant Castler, Valladao Task
Genre: h#, Retro
Computer test: HC+ Popeye v4.87 & basic retro thinking
FEN: r3k3/P7/b3r1pP/4PpBP/3nnpKR/5PRB/5PP1/7N
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-12-16 more...
2 - P0000254
Leonid M. Borodatow
7642 Die Schwalbe 133 02/1992
P0000254
(16+10)
Welches waren die letzten 7 Einzelzüge, wenn dabei keine Zugwiederholungen vorkamen?
R: 1. 0-0-0# Ke4-d4 2. e5xf6ep+ f7-f5 3. Tg6-b6+ Kf5-e4 4. c7-c8=L
play all play one stop play next play all
Die von einigen Lösern angeführte Abweichung 2. f5-f6+ Kd4-e4 3. Lh6-g7+ (und mehrdeutig weiter) ließe sich durch die Erweiterung '... keine Zugwiederholungen und keine Pendelzüge ...' (mühsam) kitten. Beim Autor hieß es bei dieser ich-weiß-nicht-wie-vielten Fassung nur 'letzte 9 (!) Einzelzüge ohne Wiederholung).
HHS meint ohnehin, daß es das ganze auch ohne die einengende Zusatzbedingung schon gibt.
Das von einem Löser angegebene 1. Ld3-h7# Th1-h8 2. Lh8-g7 Tg1-h1 3. Se1-g3 g2-g1=T 4. Th7-h8=L scheitert allerdings an der Schlagbilanz.
Anton Baumann: Neufassung vergl. P0006288 (2023-01-06)
comment
Keywords: En passant, Last Moves?, Non-standard material, Castling (wl), Promotion (L), Valladao Task (WWW)
Genre: Retro
FEN: qrB2brr/Bp2p1BB/pR3P2/1Q6/2Pk1P2/B1p2R2/2P3N1/2KR1N2
Input: Gerd Wilts, 1995-06-03
Last update: Rainer Staudte, 2019-08-11 more...
3 - P0000775
Ferad Kakabadze
1422 Die Schwalbe 30 12/1974
P0000775
(11+5) C+
#3
Welches waren die letzten 2 Einzelzüge?
1. e8=D! f5 2. exf6ep e5 3. Dxe5#
R: 1. b2-b1=L 0-0
play all play one stop play next play all
Henrik Juel: The forward play is C+ Popeye 4.61
1.e8=D thr. 2.Dc8 thr. 3.Dc3#
1... f5 2.exf6ep e5 3.Dxe5#
(1... f6 does not prevent the threat, so 2.exf6 is not considered dualistic) (2020-09-26)
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comment
Keywords: Last Moves?, Valladao Task, En passant, Promotion, Castling in the retro play, Obvious promotion
Genre: Retro, 3#
FEN: 8/3pPp2/3Pp3/4P3/1N3P2/B7/P1P2P2/kb3RK1
Input: Gerd Wilts, 1995-06-03
Last update: James Malcom, 2020-09-27 more...
4 - P0000777
Leonid M. Borodatow
1424 Die Schwalbe 30 12/1974
P0000777
(12+10) cooked
h#2.5
1. ... exf6ep 2. 0-0-0? Lxf4 3. Td7 a8=D# try
1. ... Kxf4 2. Tf6 e6 3. Tf8 Sg7# solution
play all play one stop play next play all
Cook: 1. ... Kxf4 2. Te7 e6 3. Tb8 axb8=D,T#
See P0000674
Henrik Juel: The stipulation should probably read h#2.5: 1.exf6ep 0-0-0 2.Bxf4 Rd7 3.a8Q# (2003-08-18)
Anton Baumann: Letzter Zug war f7-f5, sonst retropatt. Die weissen Bauern haben 6x geschlagen. Der s a-Bauer wurde so ebenfalls als Schlagopfer benötigt und musste 2x schlagen, um sich umwandeln zu können. Weiss hat also auf h6 den s Bauern geschlagen. Unabhängig davon ob der sTe6 ein Umwandlungsturm ist oder nicht, muss der sTh8 über e8 aus der Ecke gekommen sein. Also ist die Rochade illegal!
Autorabsicht: 1. ... exf6 e.p. 2.0-0-0 Lxf4 3.Td7 a8=D# ist die Verführung!
Lösung: 1. ... Kxf4 2.Tf6 e6 3.Tf8 Sg7#
leider geht auch: 1. ... Kxf4 2.Te7 e6 3.Tb8 axb8=D,T# (2022-12-13)
A.Buchanan: I agree Anton. I suggest as a fix -bBa6 +bDc2. I think retro, solution and try all work correctly now. Do you folks agree? (2022-12-13)
Anton Baumann: Der Vorschlag von Andrew ergibt eine korrekte Lösung, aber nicht im Sinne des Autors: ohne einen s Stein auf a6 ist f6-f5+ als letzter Zug möglich, d.h. kein Retropatt weil Weiss a6-a7 zurücknehmen kann! 1. ... exf6 e.p. ist deshalb nicht zulässig. LB wollte aber dass f7-f5 der letzte Zug war, damit aber die Rochade illegal ist! (2022-12-14)
Anton Baumann: Mögliche Korrektur: a6=sL, g2=sD (2022-12-15)
A.Buchanan: Yes I agree. I had overlooked the unmove of wPa7 (2022-12-15)
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comment
Keywords: Castling (sg), Valladao Task, Superseded by (P0000058)
Genre: h#, Retro
FEN: r3k3/P7/p3r1pP/4PpBN/3nnpKP/6PB/1P2PPb1/8
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-12-16 more...
5 - P0000793
Nikita M. Plaksin
Andrey Lobusov

1558 Die Schwalbe 33 06/1975
4. Preis
P0000793
(13+5) C+
#3 (AP)
1. cxd6ep+! Kxg3 2. 0-0! (proving ep ok)
2. ... Kg4 3. g8=D,T#
2. ... a1=D,L 3. Dg5#

R: 1. d7-d5 Tc6xh6 (unless R: Kg1-g2 Th~*h1)
play all play one stop play next play all
VL: A posteriori (AP)!
2.g8Q(R)+/Rg1+? Kf4 3.Qg5#??
Retro: d7-d5, Rc6xh6+ (unless Kg1-g2, Rh~-h1+).
One of the best AP-type problems. (2015-08-20)
James Malcom: The first Valladao AP? (2020-10-03)
A.Buchanan: Hi James, there are 6 earlier ones in PDB, not counting those which are not marked as Valladao (could quite a few, as basic AP is 2/3 of Valladao). Type k='a p' and not g='fairies' and k='valladao', and set sort order by date. The ur-problem is P0003417. (2020-10-03)
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Keywords: Castling (wk), a posteriori (AP) (Type Petrovic), En passant as key, Promotion (ws), Valladao Task (w w w/s)
Genre: Retro, 3#
Computer test: Popeye v4.85 + minor retro/AP thought
FEN: B7/p5PP/p6R/Q1Pp4/8/PP1P2P1/p3P1k1/4K2R
Reprints: (B) Die Schwalbe 48 12/1976
feenschach 40 11-12/1977
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-03-11 more...
6 - P0001107
Michel Caillaud
3332 Die Schwalbe 66 12/1980
2. Preis
P0001107
(7+9) C+
h#4.5 (AP)
Circe
1. ... hxg6ep[+sBg7] 2. a1=T+ Txa1[+sTh8] 3. 0-0 Ta3 4. bxa3[+wTa1] 0-0-0 5. Td8 Txd8[+sTh8]#
play all play one stop play next play all
Wenn die beiden Könige noch nicht gezogen haben (was a.p. durch Ausführung beider Rochaden bewiesen wird!), kann der letzte Zug nur g7-g5 gewesen sein, Sonst ginge z.B. auch R: 1. Kd8-e8 c2xDb3
Henrik Juel: A possible retroplay is -1... g7 -2.f3xP(-Pg7) b5 -3.f2 c6xP(-Pb2) -4.b2 a6 -5.Rc3 a7 -6.Rc1 b6xB -7.Bf8 b7 -8.Bg7xB etc. (2003-04-22)
Michel Caillaud: The problem is not cooked as indicated, as under A Posteriori convention both castles must be played in the solution to justify the en passant key. (2022-02-04)
A.Buchanan: If wK never moved, then Black has not just moved another non-capturing pawn, as White has no prior move. The only possible exception is R: 1. g7-g5 f/h3xPg4[+Pg7]. (2022-02-04)
comment
Keywords: a posteriori (AP), Circe, En passant as key, Castling (wgsk), Promotion in forward play, Valladao Task
Genre: Retro, Fairies, h#
Computer test: HC+ all solutions begin with ep, but only one includes both white & black castling
FEN: 4k3/8/7p/p1p3pP/Pp4Pp/RP4p1/pP6/4K3
Reprints: feenschach 61, p. 534, 08/1982
RA152 diagrammes 72 07-08/1985
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2023-06-28 more...
7 - P0001270
Matti Arvo Myllyniemi
142 Europe Echecs 84 01/1966
P0001270
(15+15) C+
BP in 9.5
1. e3 d5 2. Lc4 d4 3. Se2 d3 4. 0-0 dxc2 5. d4 Kd7 6. d5 Kd6 7. Dd4 Sd7 8. Ld2 c1=L 9. Lb4+ c5 10. dxc6ep+
play all play one stop play next play all
more ...
comment
Keywords: Unique Proof Game, En passant, Non-standard material (l), Castling (wk), Promotion (l), Valladao Task (sww)
Genre: Retro
Computer test: Ergänzung Stelvio 1.2 C+: Keine Lösung: BP 8.5, 9.0. 10. dxc6ep++ Doppelschach.
FEN: r1bq1bnr/pp1npppp/2Pk4/8/1BBQ4/4P3/PP2NPPP/RNb2RK1
Reprints: 92 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2023-05-25 more...
8 - P0001622
Christian Poisson
491b Europe Echecs 355/356 07-08/1988
P0001622
(3+11)
shc#11
1. Lf1 2. Kh3 3. Kh4 4. Lh3 5. fxg3ep 6. Kh5 7. Kg6 8. Kf7 9. Ke8 10. 0-0-0 11. Td7 a8=D#
play all play one stop play next play all
The cluster of tries: Kh2-g1-f1-e1-d2-...-e8 0-0-0 Td7 is 12 moves: just too long.
In the diagram, e.p. is not permitted because last move might be g3-g4. So first shift sK to h4. Following the e.p., check that wK does now have prior move: Kf4-f3. Now sK scampers to e8 where through consequent forgetfulness it recovers castling rights.
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Keywords: En passant, Castling (sg), Seriesmover, Consequent, Valladao Task, Promotion in the mating move (D), Switchback (l), Promotion (D), Königswanderung
Genre: Retro, Fairies
FEN: r7/P1p5/pp6/5pp1/5pP1/5K1b/4rp1k/8
Input: Gerd Wilts, 1995-06-03
Last update: James Malcom, 2021-09-14 more...
9 - P0001764
Henri Nouguier
25 Phénix 1 05/1988
P0001764
(9+13) cooked
shc#6
1. dxc3ep 2. Kxb5 3. Kxc6 4. Kd7 5. Ke8 6. 0-0 Th8#
Aber es geht auch R: 1. Kb2-a1!?
play all play one stop play next play all
Henrik Juel: The intention may be 1.dxc3ep 2.Kxb5xc6-d7-e8 6.0-0 Rh8#, but -1.Kb2 seems possible. Should bBc1 be moved to a3? (2003-04-28)
GW: Yes, that's the solution, and the problem seems indeed to be cooked. I don't know if it has been corrected. (2003-04-28)
James Malcom: I believe that the intent was that the sLc1 must be the orginal one, and thus an impediment to wK foreplay, as the wBc6 "must" have captured the e7 Black pawn on its way from f2. The problem is that it can take the alternative path fxsLf3xDe3xTc5-c6, and there are enough White pieces to capture for the Black b pawn to make it d2 and for the d pawn to make it to c2. (2021-09-14)
James Malcom: It turns out this problem actually was corrected a long time later: P1012052 (2021-09-14)
comment
Keywords: En passant, Castling (sk), Seriesmover, Consequent, Non-standard material (sLb1), Valladao Task, Promotion in the retro play (sLb1), Obvious promotion ((sLb1)), Superseded by (P1012052)
Genre: Retro, Fairies
FEN: 7r/5pnR/2P3pR/pPpn3p/1kPp4/3P4/P2pP3/Kbb5
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-09-14 more...
10 - P0002353
Theodor Tauber
Michel Caillaud

The Problemist 1991
P0002353
(14+11) C+
ser-h#3 (AP)
1. dxe3ep 2. fxg1=L 3. 0-0 Tg4#
1. dxe3ep 2. Ke7? 3. Kd6 Sf5# doesn't pay AP debt
play all play one stop play next play all
Henrik Juel: If Black may castle, his latest move must have been e3xf2, so last move was e2-e4. (Orig. wPg2 promoted on g8, so g7xh6 happened early). 1.dxe3 e.p. 2.fxg1=B 3.0-0 Tg4# (2003-03-21)
James Malcom: Is this the only know one-sided Valladao in a regular series-mover helpmate? Also, can wPh2 be shifted to h4, and the White king moved as well to h2, so that the solution must have 2. fxg1=S? (2020-12-08)
James Malcom: Well, the only known one that is in minimum form, i.e. 3 moves, I mean. (2020-12-08)
A.Buchanan: This is nice. I don't know of any other AP ser-h#3 with Valladao, but there could be. Just been cleansing PDB data today. Yes I think wKh3 and wBh2 can be transposed, and then promote to S instead of L. (2020-12-08)
A.Buchanan: The legality of intermediate positions in seriesmovers is of course irrelevant. However, each proof game that leads to the diagram position with BTM can be appended with a black move and then a "flip" that changes the player to move. We can repeat this process, and then the fact that Black retains castling rights implies that they had castling rights in the diagram position. I think this is the right formal way to handle AP with seriesmovers. (2022-03-21)
comment
Keywords: a posteriori (AP) (Type Petrovic), En passant as key, Castling (sk), Seriesmover, Promotion, Valladao Task
Genre: Retro, Fairies
Computer test: C+ Popeye v4.85 + thinking
FEN: 4k2r/1pp2p1p/1N5p/3P4/2RpP2N/P2P1P1K/p1BP1p1P/B3b1R1
Reprints: Die Schwalbe 143 10/1993
Rex Multiplex 45-46 05/1994
(XII) Quartz 5 1997
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-03-21 more...
11 - P0003138
Branko Koludrovic
4208 Problem 12/1979
P0003138
(11+9)
h#3 (AP)
0.1...
1. ... axb6ep 2. 0-0-0 0-0-0 3. Td7 a8=D#
play all play one stop play next play all
This problem can be solved presuming that both castlings are executable. It implies that the last halfmoves have been.-1.Bb6xa7 sBb7-b5.
Bb5 could not come from c6 (sBc6xFb5), because all of the missing white pieces(5) have been captured on white squares except wLc1,which must have been captured by Bc7(Bc7xwLb6).Further,it has not played immediately before -1.Bb6-b5 because this would prevent white castling(forcing wT or wK to move)
Here is the proof that 4 remaining white pcs have been captured on white squares:
black d-pawn must have been captured on d4 and h,g f pawns had to promote after Bh3xwFg2,then wBh2moved to h4, enabling Bg4x Fh3 ..h1T, and finnaly sBf7
after fxg2... g1S. sLf1 prevented the check from Th1, and later has been captured by a white officer.
Conclusion:
Retro:-1.wBb6xFa7 Bb7-b5
Forward(AP) 1....axb6 e. p.2.0-0-0 0-0-0 3.Td7 a8Q# (Author)
Branko Koludrovic: P.S.
The black pawn a4(on the diagramm)came from c7 after capturing the white bishop on b6, then moving to b5 and capturing a white officer on a4. (2010-09-28)
A.Buchanan: I think sBf must have captured on g2 & then promoted on f1 to S, otherwise it’s impossible to unlock the southeast cage (2023-07-11)
A.Buchanan: So that means it’s sound. However I don’t see that it needs to have been sL shielding on f1 (2023-07-11)
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Keywords: a posteriori (AP), En passant as key, Castling (sgsgwg), Promotion (D), Valladao Task
Genre: h#, Retro
FEN: r3k3/P3p3/p7/Pp6/p6P/2P3PR/2PPP2b/R3K1nr
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2023-07-11 more...
12 - P0003417
John Frederick Keeble
2206 The Problemist Fairy Chess Supplement 16, p. 173, 02/1936
P0003417
(4+5) C+
h#2.5 (AP)
1. ... exd6ep 2. 0-0-0 dxe7+ 3. Tf8 exf8=T,D#
play all play one stop play next play all
H.Juel: If Black may castle, last move was not made by Ke8 or Ta8, but by Pd5, so it was d7-d5, and hence White may capture en passant. 1... exd6ep 2.0-0-0 dxe7 3.Tf8 exf8=D,T# where the castling (belatedly) justifies the e.p. capture.
Not 1... exd6ep 2.Kd8? dxe7 3.Kc8 e8=D,T
AB: Another 120 retro tries (=60x2 due to tolerated dual promotion) of general form 1. exd6ep 2. T~ dxc7 3. T~ c8=D,T.
No set play
Nachdruck in "Die Schwalbe" 33 mit Diagrammfehler (wBe6 fehlt).
VL: The first AP-problem! Thematic illegal try:
1. ... exd6ep 2.Kd8? dxe7+ 3.Kc8 e8=T(D)#?? (2007-02-11)
Mario Richter: 46 years between this Problem and P1366663 - perhaps this was not Keeble's first AP-Problem?! (2019-08-29)
Ladislav Packa: Of course I know the idea a posteriori. But let my heresy be forgiven - I do not consider it logical. In this particular example, I consider e.p. for proof that black can castling - not vice versa. (2019-08-29)
A.Buchanan: Hi Ladislav. If ep is ok, then Black just moved a pawn with double hop. That doesn't stop Black having e.g. moved bK right at the beginning of the game. So you can't prove that Black definitely can castle this way. What am I missing here? (2019-08-29)
Ladislav Packa: Your statement is perfectly fine. However, the AP condition is usually interpreted as castling is evidence of e.p. However, the second party does not have to do castling - the possibility has already been demonstrated by the existence of e.p. (2019-08-29)
A.Buchanan: Hi again Ladislav. Please try again, I am obviously being very stupid. I don't understand how 1. exd6ep is any more indicative that Black can castle than 1. K~. (2019-08-30)
Ladislav Packa: Hi, Andre!
e.p. is just a result of the d7-d5 move. Black can castle only if it was the last move of black (even without wPe5). Therefore, it does not have the logic of joining the e.p. with castling. For example, ask yourself if black is allowed to castle in the position without wPe5. (2019-08-30)
A.Buchanan: @Ladislav: ep is not "proof that black can castle", rather it is a *necessary* condition for Black to be able to castle. The logical implication is the other way round. We can castle because of the optimistic convention, and because sPd might just have moved. Without wPe, there is no solution, but whatever White plays, Black can castle (2020-12-11)
Hans-Jürgen Manthey: was heißt hier Thematisch Illegal ??
Mir völlig wurscht ob ep möglich oder nicht, nach dem weißen Zug ist natürlich Kd8 möglich !!
also ist auch 1. ... exd6ep 2. Kd8 dxe7+ 3. Kc8 e8DT# eine Lösung, sonst müßte auf die erzwungende Rochade in der Aufgabenstellung hingewiesen werden ! (2020-12-11)
A.Buchanan: Can one tolerate “tolerated dual promotion” in Valladao? Well Valladao himself did, so it must be ok (2022-03-26)
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Keywords: a posteriori (AP) (Type Petrovic), En passant as key, Castling (sg), Promotion (D/T), Tolerated dual promotion (D/T), Valladao Task, Retro Strategy (RS)
Genre: h#, Retro
Computer test: Popeye 4.61
FEN: r3k3/2p1p3/2P1P3/2KpP3/8/8/8/8
Reprints: V. Die Schwalbe 33, p. 323, 06/1975
2001 CHM Themes 12/2000
3 Die Schwalbe 215, p. 240, 10/2005
A1 Problemkiste 169 02/2007
402 Eigenartige Schachprobleme , p. 130, 2010
14 Die Schwalbe 241, p. 374, 02/2010
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-06-10 more...
13 - P0003423
Matti Arvo Myllyniemi
3975 Stella Polaris 01/1971
P0003423
(7+11)
h#3 (AP)
0.2.1...
1. ... g6 2. 0-0 gxf7 3. Kh8 Le5#
1. ... cxb6ep 2. 0-0-0 bxa7 3. Td7 a8=D#
play all play one stop play next play all
Henrik Juel: Analysis
If Black can castle both ways, last move must have been b7-b5
C+ Popeye 4.61 (2020-10-25)
comment
Keywords: a posteriori (AP), En passant as key, Castling (sksg), Promotion (D), Valladao Task
Genre: h#, Retro
FEN: r3k2r/p4p1p/8/KpP2PP1/4PBpP/5pp1/6p1/8
Reprints: Nordisches Turnier 1970-1971
Input: Gerd Wilts, 1995-06-03
Last update: James Malcom, 2020-10-25 more...
14 - P0004036
Sergey A. Komarov
Andrey Frolkin

diagrammes 85bis 04-06/1988
3. Lob
P0004036
(5+15)
shc#7
1. a1=S 2. fxg3ep 3. Kxh5 4. Kxg6 5. Kf7 6. Ke8 7. 0-0-0 a8=D#
play all play one stop play next play all
8. TT
Henrik Juel: Solution: 1.a1S 2.fxg3ep 3.Kxh5xg6-f7-e8 7.0-0-0 a8Q#. Nice problem with open and hidden ep capture (exf3ep). (2003-04-28)
James Malcom: How is the key here justified? (2021-01-18)
James Malcom: I am still pondering. (2021-09-14)
Henrik Juel: James, I have forgotten all about this weird stipulation during the time since my last comment, and I don't know what I meant so say...
The definition of shc in the PDB is not complete; here is the Schwalbe definition:
Konsequenter Serienzüger: Ein Serienzüger, bei dem nach jedem Zug die Retroanalyse der Stellung neu durchgeführt wird (also ohne Kenntnis früherer Züge und Analysen). Beispielsweise wird eine Rochade wieder möglich, wenn König und Rochadeturm auf ihre entsprechenden Felder ziehen (weil in der neuen Analyse "vergessen" ist, dass beide bereits gezogen haben).
In english, something like
After each move the analysis of the position is done afresh, without knowledge of previous moves;
for instance, castling is possible when king and rook reach their original squares (e8 and a8), because it is 'forgotten' that they have already moved (2021-09-14)
Henrik Juel: You ask for a justification of the key, James; there is no need for justification, Black can do whatever he likes
In the position after 1.a1=S last move must have been g2-g4, so the ep capture 2.fxg3ep is legitimized
In the position after 2.fxg3ep last move must have been Ke3xPf3, with the double check being explained by exf3ep++; this is the 'hidden ep capture' I mentioned in my youthful comment (2021-09-14)
James Malcom: Thanks Henri! While the definition is incomplete, the reset each time is deducible from looking over shc problems. The justification here, however, was a level above me somehow. (2021-09-14)
comment
Keywords: Seriesmover, Consequent, En passant, Promotion (sD x2), Valladao Task, Castling, Promotion in the mating move
Genre: Retro, Fairies
FEN: r7/P1pp4/pp3pP1/4rpbP/5pPk/3n1K1b/p6q/8
Input: Gerd Wilts, 1995-06-03
Last update: James Malcom, 2021-09-14 more...
15 - P0004481
Matjaz Zigman
Länderkampf Mazedonien-Slowenien 1969
7. Platz
P0004481
(13+10) cooked
ser-h#6** AP
* 1. ... Sb5#
* 1. ... dxc3#
1. fxe3ep 2. e2 3. exf1=S 4. Se3? 5. Sd5 Sb5# (must castle for AP)
1. fxe3ep 2. e2 3. exf1=S 4. Sxd2 5. Sxb1 6. Sxa3 0-0-0!#
play all play one stop play next play all
Luckily, illegal diagram can be fixed by removal of bPa4.
Then if White castling rights remain, ep is on. One ser-h#5 & 18 ser-h#6 tries exist, in which White does not bother to castle.
We don't know if this was a transcription error or a counting mistake by the composer.
Cook: Too many pawn captures required. For retro problem, illegal position implies unsound
Mike Neumeier: The solution appears to be 1.fxe4 e.p. 2.e2 3.exf1=L 4.Ld3 5.Le4 6.Ld5 dxc3#. Was that the intention? (2013-02-18)
Arno Tüngler: There would even be a solution in 5 moves by 3.exf1=S 5.Sd5 Sb5#
However, in order to justify the e.p.-key there must be an AP prove that e2-e4 (and not a move by the wK or wRa1) was played as White's last move. Thus the only solution giving this in 6 moves is 1.fxe3 e.p. 2.e2 3.exf1=S 4.Sxd2 5.Sxb1 6.Sxa3 0-0-0!# (2013-02-18)
Mike Neumeier: It struck me as odd there was no solution listed. (2013-02-18)
Mike Neumeier: And, if we let black be the idle side, there is 1.Txg1 2.Lxh1 3.Kd1 4.Kc1 hxg1T#. What does the asterisk(*) mean? (2013-02-18)
Henrik Juel: The asterisk means that there is also a white mate if he had the move, in this case two mates, so maybe the stipulation should be ser-h#6**:
1.dxc3,Sb5# (2013-02-18)
Ladislav Packa: It is clear that e.p. is possible only when the wK and wRa1 done neither move.
What convention is used here for the right to castling? (2013-02-18)
Henrik Juel: White may castle, unless you can show that he has lost the right to castle. In this problem there is a major difficulty, I think: the position seems illegal.
White pawns captured b2xc3xd4xe5xf6, g2xf3, and axb, promoting on b8; Black captured bxc, dxc, and g3xh2. We cannot explain the destiny of [Ph7].
Reversing wPh3 and bPh2 seems to handle the illegality, but then the problem can be solved in 5 moves (2013-02-18)
Mike Neumeier: Thanks, Henrik. Maybe the stipulation was a typo. Considering all comments together, perhaps the stip should have been ser-h#5**, with the one solution being the 5-mover Arno gave. I do not think it can be proven, except by a stipulation of ser-h#5 that en passant is possible. Which leads to the question of convention. Can the existence of a unique solution as implied only by the stipulation be used to determine that en passant is permissible? Whether there is castling or not here seems immaterial. It is just another 6-move solution. There are 19 6-movers (Popeye) with one queenside castling among them. But only the one 5-mover. (2013-02-18)
Henrik Juel: By convention, an en passant capture as first move is not permitted, unless the pawn double step can be shown by some kind of retro analysis.
(Conversely, a castling is permitted, unless it can be shown by retro analysis that the right to castle has been lost, i.e., that king and/or rook has moved) (2013-02-18)
A.Buchanan: Suggested repair: Remove bPa4. Add AP to stipulation.
As Henrik points out, the diagram as it stands is illegal. We can't swap wPh3 & bPh2, because that allows 2 h#1 cooks.
Suppose we remove bPa4 instead. Then we still at least 5 White pawn captures: bxcxdxexf6 & gxf3. But wPh3 did still move from h2, so there are 3 Black pawn captures bxc, dxc & gxh2. So [bhP] died without capturing or promoting. [waP] must have promoted - so either [baP] was captured to clear the way, or [waP] captured to promote, and later [baP] promoted. Either way, all the numbers add up, and the position is legal. wPe4 cannot have just come from d3. So AP is triggered. Forward logic works just as before without bPa4. There is 1 5-move try, and 18 6-move tries, but AP eliminates them all because of need for castling to retrospectively justify the ep. (2013-02-23)
A.Buchanan: Mike asked: "Can the existence of a unique solution as implied only by the stipulation be used to determine that en passant is permissible?"
Answer: No. The stipulation does imply a default player to move, but otherwise cannot be used as a premise to determine game state (castling, en passant). (2022-03-21)
A.Buchanan: WinChloe & Yacpdb have the same cooked diagram as PDB, so I think this cook was in the design. I would like to post a sound version with bPa4 removed, and I think it would just be “Zigman correction” with no one else’s name mentioned in the credits. Is everyone ok with this? (2022-05-30)
Mario Richter: 'Bilten 1970' (printed 1971) contains on pp. 62-81 a complete report on the "Problem Duel Slovenia - Macedonia 1969", the problem here can be found on page 79 and is printed there exactly as given here.
Andrew's handling of the suggested correction (remove black pawn a4) is o.k. for me. (2022-05-31)
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Keywords: Castling (wg), Seriesmover, a posteriori (AP) (Type Petrovic), Illegal position, En passant as key, Promotion (s), Valladao Task, Superseded by (P1401546)
Genre: Retro, Fairies
Computer test: Popeye v4.87 but simple retro-logic shows illegality
FEN: 8/8/5P2/2p1p3/p1pkPp2/N1p2P1P/2PP1PBp/RN2KRbr
Reprints: 104 Bilten 1970 1971
(72) Problem 144-147 12/1971
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-06-01 more...
16 - P0006423
Andrey Frolkin
9128 Die Schwalbe 157, p. 283, 02/1996
Leonid Borodatow gewidmet
P0006423
(9+4)
#3 (AP)
White pushes the move (Keym AP)
1. ... f5! (f6?,fxe6?,fxg6? 2.0-0! ~ 3.Tf3#) 2. gxf6ep! exf6 3. 0-0! f5 4. Tf3#
(2. 0-0=?)
Valladao Task via the try: 1. exf7? e5! 1. ... e6? 2. f8=D e5 3. Da3#
Another try shows fully differentiated black Albino:
1. Kf1? fxg6!
1. ... f5? 2. Lxf5! h3 3. Txh3#
1. ... fxe6? 2. Lxe6! h3 3. Txh3#
1. ... f6? 2. Lf5! h3,fxg5 3. Txh3#,Th3#
And retro tries:
1. 0-0?? f5,~ 2. Tf3# (short solution)
1. f5? f6,~ 2. 0-0?? fxg5,~ 3. Tf3#
play all play one stop play next play all
Wenn Schwarz zuletzt gezogen hat, dann kann Weiß nicht mehr rochieren: R: 1. Kh2-g3 Tf1(g1)-h1+. Da aber Weiß in einem direkten Matt beginnt, ist die Rochade nicht mehr zulässig. Der Zusatz "AP" in der Forderung ist überflüssig: es könnte höchstens der Anzug a posteriori dem Schwarzen übertragen werden. Das geht aber nicht, da Weiß in einem direkten Matt beginnt.
Guus Rol: This is apparently AP after Keym. The move goes to black:
0. ... f5! 1.gxf6ep exf6 2.0-0(justifies the handover) f5 3.Tf3 (2007-02-13)
A.Buchanan: There are two kinds of directmate Type Keym. In one Black unsuccessfully pulls the move, in the other (as here) White successfully pushes it to Black. (2022-04-16)
A.Buchanan: I disagree with the German comment in the solution text. I think including "AP" is advisable in the stipulation. Keym AP riffs off Codex Article 15, but it's not the default. (2022-04-17)
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Keywords: a posteriori (AP) (Type Keym), Castling, En passant, Promotion (D), Valladao Task
Genre: Retro, 3#
FEN: 8/4pp2/4P1N1/6PP/5P1p/6kB/6P1/4K2R
Input: Gerd Wilts, 1996-06-12
Last update: A.Buchanan, 2022-04-18 more...
17 - P0008793
Andrej N. Kornilow
Shakhmaty v SSSR 1978
P0008793
(15+8)
#1.5
a) 1. "Ta1-d1+?" ... Td4 2. Txd4# (Completing the illegal castling!)
b) 1. "xc5ep+?" ... Tb5 2. Txb5# (Completing the illegal e.p.!)
c) 1. "xe8=S+?" ... e6 2. Sf6# (Completing the illegal promotion!)

0) 1. Sxe7+! Lxe7 2. f8=B# (Truncating the promotion move!)
play all play one stop play next play all
n in directmate stipulation #n means that White has n moves to do the job. With n=1.5, therefore, one of the White moves is fractional, so we know we are in the realm of jokes, ho ho!

If White's first move is the fractional one, there are three retro tries which attempt to complete: castling, ep & promotion. However all are illegal:
castling: 8 white pawns, so wTa5 came from h1, dislodging wK.
ep: retracting sBc5 to c7 means wLb8 is promoted, but 8 white pawns.
promotion: white made 7 pawn captures, while sBgh were waylaid.

So we consider that White's second move was the fractional one, by omitting the replacement of wBf8 by an officer.
Henrik Juel: Completing the key isn't legal, 1.'Rd1'/'-bPc5'/'e8S'+, but omitting the promotion in the mating move is, 1.Sxe7+ Bxe7 2.'f8'#. Excellent joke. (2003-09-19)
James Malcom: A very witty joke Valladao! (2020-09-24)
A.Buchanan: Really like this joke (2020-09-25)
Henrik Juel: To see the illegality of completing 1.fxe8=S+?, note the captures:
Black captured fxDe, so [Pg7,h7] were captured on their files, while the other six missing black men were captured by white pawns
The illegality of completing 1.0-0-0,bxc6ep? is rather obvious (2020-09-26)
James Malcom: And for those you don't find it obvious: If the White king hasn't moved, then where did wRa5, and wBb8 if bPb5 has just done a double-step, come from? Neither can be promoted pieces, as White still has all eight pawns. Trying to finish castling and en passant therefore both produce illegal positions and thus cannot be the solution. (2020-09-26)
Henrik Juel: Continuing beating the dead horse...
How does the white player actually perform an entire move?
1.0-0-0+: Ke1-c1 and Ta1-d1
1.bxc6ep+: Pb5-c6 and remove sPc5
1.fxe8=S+: remove sYe8 and Pf7-e8 and replace wPe8 with wSe8 (three fractional actions)
2.f8=Y#: Pf7-f8 and replace wPf8 with wYf8
So a marginally better stipulation might be: 'White to move mates in less than 2 moves' (2020-09-26)
A.Buchanan: Hurray I've got the animation working! I agree with Henrik's stipulation. There is a dummy pawn on f8, but not by the Dummy Pawn rule. Instead it's the joke that does it. If Dummy Rule applied, the move would be full length! :) (2022-02-09)
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Keywords: En passant, Start a move but do not finish it, Castling, Promotion (S,B), Valladao Task (half!), Joke (End move, Start move), Dummy Pawn (not! Start move), Complete an unfinished move, waylaid (sBgh)
Genre: Retro, 2#
FEN: 1B1N1bB1/p2ppP2/2P5/R1pk1N2/1r2p3/1P2P1P1/4PP1P/R1K5
Reprints: (III) Quartz 4 1997
Input: Gerd Wilts, 1997-06-21
Last update: A.Buchanan, 2023-04-08 more...
18 - P0008794
Alexandr A. Klibanski
2 Shakhmaty v SSSR , p. 31, 07/1977
P0008794
(14+4)
#1
1. Tb1#
zuletzt geschah
R: 1. ... Kc2-b2 2. e5xf6ep+ f7-f5 3. e4-e5+
oder
R: 1. ... Kc1-b2 2. 0-0+
oder
R: 1. ... a2-a1=L
play all play one stop play next play all
weiße Bauernschläge: axb3,b2xc3xd4xe5xf6,c2xd3xe4xf5xg6xh7-h8=L,e2xfxg = 12 Schläge, alle fehlenden schwarzen Steine sind erklärt, insbesondere hat der wBh2 nie die h-Linie verlassen.
Der sBh4 stammt also entweder von f7 (2 Schläge) oder von h7 (ebenfalls 2 Schläge, um den wBh2 vorbeizulassen). Damit sind auch alle fehlenden weißen Steine erklärt. Da zu diesen auch der schwarzfeldrige wLc1 gehört, kann zuzletzt nicht h5-h4? geschehen sein ('Shakhmaty v SSSR' nennt das "Farbeffekt").
paul: La question est si les Blancs sont a jouer et le reponse est affirmative. Les seuls retro-jeux plausibles sont:
1.Rc1-b2 0-0;
1.Rc2-b2 e6xf6 e.p. 2.f7-f5 Tg6-a6+;
1.a2-a1F.
Donc le task Valladao. Le coup matant est 1.Tb1#
Est interessant a voir pourquoi ne va pas le retro-jeu h5-h4?.
L?analyse demontre que le seul Pion blanc transforme en en h8 a ete Pc2 et la sequence des coups a ete c2xd3xe4xf5xg6xh7-h8F. Le P blanc h6 vient de h2 sans captures, donc le P noir h4 a effectue deux prises, don?t une d?un F blanc de camps noirs. Donc h5-h4 est illegal. (Quartz 4/1997) (2010-03-22)
Henrik Juel: For the benefit of readers, whose French is a bit rusty:
Paul points out that the retroplay given on top is incorrect. Ph4 is [Pf7] who captured the dark-squared [Lc1] on its way to h4; so its latest move was g5xh4, not h5-h4. (2010-03-26)
Paulo Roque: Henrik:
Not R: 1.h5-h4. See also that [Pa7] was promoted in the square a1, at some point. But I think also possible Ph4 is [Ph7], by: h7xg6-g5xh4 or h7-h6xg5xh4 (2010-03-27)
Henrik Juel: You are right, Paulo; my mistake, not Paul's. I should have written: Ph4 is [Pf7] or [Ph7], who captured the dark-squared [Lc1] on its way to h4; so its latest move was g5xh4, not h5-h4. (2010-03-27)
James Malcom: Question: What prevents the Black king from going to c1 after castling is retracted? (2022-06-17)
comment
Keywords: En passant in the retro play, Castling, Promotion in the retro play, Valladao Task
Genre: Retro
FEN: 6NB/Q5pB/R4P1P/6P1/7p/1P4P1/1k1P1P2/b4RK1
Reprints: (V) Quartz 4 1997
Input: Gerd Wilts, 1997-06-21
Last update: Mario Richter, 2022-06-17 more...
19 - P0008845
Gianni Donati
62 Quartz 5 1997
P0008845
(11+11) C+
BP in 11.5
1. d4 e5 2. Lg5 Dxg5 3. a4 Dxg2 4. a5 Dxg1 5. a6 Dg6 6. axb7 a5 7. dxe5 Da6 8. Dxd7 Kxd7 9. Lh3+ f5 10. exf6ep+ Kd6 11. 0-0 Sxf6 12. bxc8=S+
play all play one stop play next play all
White consecutively plays the three thematic moves. This PG cannot be extended to move beyond the check in the final diagram.
Henrik Juel: The ep capture is well hidden, and it is not obvious that Sc8 is promoted as Sg1-c8 also takes five moves
Interesting that Euclide 1.01 is 10 times faster than Natch 2.3 here (2021-07-04)
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Keywords: Unique Proof Game, En passant, Castling (wk), Promotion (S), Valladao Task (www), Phoenix (S)
Genre: Retro
Computer test: C+ Natch-2.3 11m 28.52s C+ Euclide 1.01
FEN: rnN2b1r/2p3pp/q2k1n2/p7/8/7B/1PP1PP1P/RN3RK1
Input: Gerd Wilts, 1997-10-19
Last update: A.Buchanan, 2021-07-04 more...
20 - P0009099
Klaus Wenda
4123 diagrammes 127 10/1998
P0009099
(11+5)
s#12
Längstzüger
1. a8=T+ Kd7 2. e8=L+ Ke6 3. f8=S+ Kf5 4. c8=D+ Se6 5. 0-0-0 Ke4 6. Dxc6+ Kf5 7. g4+ fxg3 e.p. 8. Df3+ Sf4 9. Lb5 axb5 10. Ta1 bxc4 11. Tab1 cxb3 12. Dd3+ Sxd3#
play all play one stop play next play all
paul: Cooked by 1.f8=Q Kd7 2.c8=B Kd6 3.e8=S Ke5 4.Ra5+ Kd4 5.Qc5+ Ke4 6.Re3+ fxe3 7.Qxc6+ Kd3 8.Bf5+ Se4 9.Kd1 exd2 10.Qf6 Kxc4 11.Be6+ Kd3 12.Qc3+ Sxc3#

2... Kc7 3.a8=S+ Kd6 4.e8=S++ Ke5 5.Re3+ Se4 6.d4+ Kxd4 7.Rd1+ Sd2 8.Rf3 Ke5 9.Qf5+ Kd4 10.g3 fxg3 11.Re3 Kxe3 12.Qf2+ gxf2# (Jacobi)
See P1287941 as correction. (2022-04-06)
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Keywords: Valladao Task, Allumwandlung
Genre: Fairies
FEN: 2k5/P1P1PP2/p1p5/6n1/2P2p2/1R5P/3P2P1/R3K3
Input: Gerd Wilts, 1999-02-27
Last update: Olaf Jenkner, 2013-09-22 more...
21 - P0009121
Tomislav Petrovic
2949 Phénix 69 12/1998
P0009121
(10+9) C+
h#2 (AP)
1. fxe3ep d8=S 2. Kxd5 0-0-0# (Td1#?)
play all play one stop play next play all
White has made 6 pawn captures with one missing black piece unaccounted for, that by parity can only have been captured by an officer. White's last move cannot have been a pawn capture. If R: 1.f2-f3, then sLg1 was promoted, implying 7 captures by black pawns - one too many. So if White can prove they retain castling rights, then the ep is on. Hence AP Petrovic is valid.
Henrik Juel: 0... fxe3ep 1.d8S Kxd5 2.0-0-0#. Not -1.f2? and Lg1 is caught. (2004-09-16)
Vaclav Kotesovec: Similar problems should not be labeled as "C+". Such a designation is only acceptable if the entire analysis was performed by a computer program. (2023-08-03)
Henrik Juel: In principle I agree, Vaclav
But PDB does not (yet) allow HC+, so I find it acceptable to use the C+ label, when you also tell the whole story after 'Computer test:' below (2023-08-03)
A.Buchanan: Hopefully Gerd will have more time at some point, and can expand the functionality in this and other areas. In the meantime, engine solving of conventional retros including AP, is in its infancy. Retractor 2 has some effectiveness, but is still basic. And there is nothing that yet grasps the intricacies of castling/ep etc. However AP problems do often contain considerable forward chess, and the C+ tag is very useful to filter out those that have already been solved forwardly, without pretending that these are in any sense fully solved (2023-08-04)
Ladislav Packa: I know the definition of AP, but I don't understand the logic behind it. The move 1.fxe3 e.p. proves that White CAN castling. But the solution (2. ...Rd1#?) claims that castling is MANDATORY. From my point of view, AP is correct when only castling is necessary for the solution and the Rook move would be a dual. (2023-08-04)
A.Buchanan: @Ladislav: I am not sure how to help you. Maybe you can read this page from Retro Corner: https://www.janko.at/Retros/Glossary/APosteriori.htm (2023-08-05)
Ladislav Packa: Andrew, what should the article help me with? I quote the final sentence:
Some people still oppose this rule and argue that it should certainly not be the default convention. (2023-08-05)
Henrik Juel: You could view it this way, Ladislav
h#2 means that it is Black to move, so White made last move
What was last move? A little analysis shows just three possibilities: f2-f4, move by Ta1, or move by Ke1
So normally we cannot assume that last move was f2-f4
But if White can castle, then the last move was f2-f4
So if we could start with 0... 0-0-0, then 1.fxe3ep would be legitimate
AP says that you are allowed to reverse the sequence of events; first do the ep capture, then later legitimize it by castling
Was this helpful? (2023-08-05)
Ladislav Packa: Henrik, you don't have to explain that to me. I've done a few AP issues myself, like P1348357. But that doesn't mean I agree with AP's logic. I already wrote it - the term "you can castle" is applied as "you must castle". But these are only problems where, in addition to castling, the Rook move can also be used, I consider that a dual.
From that point of view, the P1000662 issue is perfectly fine for me. (2023-08-05)
Joost de Heer: AP: By castling, you prove a posteriori that the ep-capture was not just a try but the actual solution. Without castling, the ep-solution just is that: a try.
So: Try 1. fe3 ep e8=S 2. Kd5 Rd1 - but ep capture not allowed, as there is no proof that f2-f4 must've been the last move.
Solution 1. fe3 ep e8=S 2. Kd5 OOO - Now the ep capture was justified because white castled, thereby proving that the last move before the diagram position indeed was f2-f4. (2023-08-06)
Joost de Heer: See e.g. P1052919 : The try is an ep capture which is unjustified. (2023-08-06)
A.Buchanan: OK Ladislav: I think I get your point. If one solution with castling justifies the e.p., then based on that certainty, why shouldn't an alternative solution with no castling *then* be allowed as well? There are problems in which one twin shows 0-0-0 and the other shows 0-0. Each is based on the other in a similar way, so the idea of dependency is not new. Why are we not allowed to add other "parasitic" solutions as well? Why can we only have the "paying" solutions? We can't say that we are restricted to one solution: that's not the way chess problems operate! And this is just in the help world - in the adversarial world it might get even more complicated. Is this your issue, Ladislav? (2023-08-07)
Ladislav Packa: I don't want to unnecessarily prolong this discussion. However, I will add one more note: in this position, white castling is also possible without e.p. in Black's 1st move. If B1 were an indifferent move, then white can 1...0-0-0! The Codex of Chess Composition writes about it in Article 16 (1):
Castling convention. Casting is permitted unless it can be proven that it is not permissible.
In our case, 0-0-0 is possible because White's last move exists - e2-e4! It does not matter if it is this move or some a2-a3, both moves are equivalent. EP does not prove the possibility of casting, it would be legal even without it. (2023-08-07)
A.Buchanan: Ladislav was what I wrote your issue pls? Y/N :-) (2023-08-07)
Ladislav Packa: I have no problem, I'm just expressing my own opinion about the AP convention. (2023-08-07)
A.Buchanan: OK cos I think the point I raised is a real one that should be addressed by theory some day. Clearly from the nice problem that you composed Ladislav you understand the mechanics very well. From a justification perspective it's all a bit iffy, but that's why it's controversial. Under RS it's really the only way one can end up actually eping, and it's proved compositionally fertile. So that's enough to justify (2023-08-08)
Ladislav Packa: No need to apologize. This is a normal discussion with different views on the issue. Maybe it will come to some conclusion.
I just want to point out the fact that it is not the e.p. that authorizes castling, because according to the Codex castling is possible regardless of the e.p. It's the exact opposite: castling authorizes the possibility of e.p. (2023-08-08)
Joost de Heer: "I just want to point out the fact that it is not the e.p. that authorizes castling, because according to the Codex castling is possible regardless of the e.p. It's the exact opposite: castling authorizes the possibility of e.p."
You misinterpret AP. The e.p. capture does not authorize castling, castling provides a justification later on (hence the 'a posteriori') for the legality of ep.
Usually, for ep justification you need to examine all game trees that lead to the diagram, and only if all game trees end with the double-step, then ep is allowed.
With AP, you examine all the game trees including the actual play. If all those game trees have as last move before the diagram position the double step, then ep is possible.
In this case, if white doesn't castle, then there are game trees which don't have as last move the double step, and therefore AP logic dictates that the ep capture was illegal. However, all game trees which lead to the diagram and which have castling in the actual play have as last move before the diagram position the double step, hence AP dictates that the ep capture is legal. (2023-08-09)
Ladislav Packa: Joost: A simple question - is white allowed to castle after any 1st move by black (except e.p.)? (2023-08-09)
Joost de Heer: Of course he is. AP only is used to combine the ep justification with castling, not the castling right per se. (2023-08-09)
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Keywords: a posteriori (AP) (Type Petrovic), En passant as key, Castling (wg), Promotion (S), Valladao Task
Genre: Retro, h#
Computer test: HC+ Popeye v4.87 + simple retro-logic
FEN: 8/3P2p1/2PP4/1ppPp3/2pkPp2/5PP1/6Pp/R3K1b1
Input: Gerd Wilts, 1999-02-27
Last update: A.Buchanan, 2023-09-11 more...
22 - P0500634
Ante Zutic
211 Delo 20/02/1971
P0500634
(2+9) C+
h#3
1. Sg5 hxg5 2. 0-0 gxh6 3. Lh8 h7#
play all play one stop play next play all
Retro!en-passant, Rochade
Bernd Schwarzkopf: Letzte Züge: 1.Kf5xTg6 f4xg3 e.p. 2.g2-g4 Tg4-g6 oder Tg4xg6 ...
Die Rochade ist also zulässig; Schwarz hat einen Umwandlungs-Turm. (2021-09-04)
comment
Keywords: En passant, Last Moves?, Castling (sk), Promotion (t), Valladao Task
Genre: h#, Retro
Computer test: (Popeye C-Version 3.52 (2048 KB))
FEN: 4k2r/8/4nbKp/7p/7P/6pb/8/5r2
Input: Gerd Wilts, 1996-06-06
Last update: hpr, 1999-05-17 more...
23 - P1000662
Gianni Donati
R074 Probleemblad 11/1999
P1000662
(10+14) C+
h#1.5 (AP)
1. ... gxh6ep 2. exf1=L 0-0-0#
play all play one stop play next play all
Kommentare:
Als einziger letzter schwarzer Zug, der die weiße Rochade
erhält, kommt nur Bh7-h5 infrage, was dem Weißen den e.p.-Schlag
ermöglicht, um nicht die Rochade oder das Mattnetz zerstören zu
müssen (H.P.Suwe)
Gianni Donati: This intends to show the Valladao theme in the minimum number of moves. (2004-03-19)
VL: The waiting ep capture. Cf. also P1000260
(by T.Petrovic, 2000) somewhat enriched
thematically with the illegal try 2... Rd1#??. (2004-06-03)
A.Buchanan: The “illegal try” 2. Rd1+ is not actually mate because c2 is unprotected. This is kind of “logic dual” spoils the A.P. motivation for the castling (2020-05-20)
Henrik Juel: White captured h6xg7 and once more, e.g. axPb-b8=Y
Black captured cxdxe, dxexf, fxg, and once more, e.g. a2xb1=Y
Possible retroplay 1... h7-h5 2.h6xSg7 Df8-f4 3.h5-h6 Sf4-h3 4.Sh3-g1 etc., preserving the castling right
Any other black last move would force White to retract Ta1, as d2xc3, d2xe3, and h6xh7 would be illegal retractions
I agree with Andrew that the double motivation of 2... 000# is a weakness:
a. legitimizing h7-h5
b. mating (2020-05-21)
Vaclav Kotesovec: Similar problems should not be labeled as "C+". Such a designation is only acceptable if the entire analysis was performed by a computer program. (2023-08-03)
A.Buchanan: See discussion at P0009121 (2023-08-04)
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Keywords: a posteriori (AP), En passant, En passant as key, Castling, Valladao Task, Promotion (l)
Genre: Retro
Computer test: HC+ Popeye v4.87 + simple retro logic
FEN: 6n1/4p1P1/6p1/6Pp/2b1rqrb/2PkPppn/1P2pP2/R3KRN1
Reprints: König & Turm (4), p. 28, 03/2001
H Problemkiste (143) 10/2002
(V2) Problemkiste 156 12/2004
Input: Gerd Wilts, 2000-08-01
Last update: A.Buchanan, 2023-08-03 more...
24 - P1012052
Henri Nouguier
diagrammes 2004
P1012052
(9+15)
shc#6
1. dxc3ep 2. Kxb5 3. Kc6 4. Kd7 5. Ke8 6. 0-0 Txg7#
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Un des PNd a pris 1 pièce blanche. pour venir de e7. Donc les PB b, c et d ne peuvent se croiser. Le PBg6 ne peut venir de f5 car il faudrait 2 prises noires! Seule reste le dernier coup blanc 0... c2-c4 Ceci implique que le FNb1 est issue de promtion ! C'est le PNb7, il aurait pris 2 pièces blanches. Les PNg5 et h5 ont pris 2 pièces blanches.
No. 11661 HN
A.Buchanan: “Obvious promotion” is intended to refer to something visible in the initial diagram position, not what is reached during series play (2022-09-14)
A.Buchanan: Similarly “non-standard material (2022-09-14)
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Keywords: Seriesmover, Consequent, En passant as key, Promotion in the retro play (sLb1), Castling, Valladao Task
Genre: Retro, Fairies
FEN: 7r/5pnR/5PnR/1Pp2ppq/1kPp4/p2P4/P2pP3/Kbb4r
Input: Henri Nouguier, 2004-01-11
Last update: Mario Richter, 2022-09-14 more...
25 - P1017610
Michel Caillaud
Kevin James Begley

R0083 StrateGems 15 07-09/2001
2. ehrende Erwähnung
P1017610
(15+5)
Welches waren die letzten 7 Einzelzüge?
Circe Parrain
R: 1. 0-0[+wBc4]+ sBd4x[Dc3,Bc4]c3ep 2. c2-c4[+wDc3]+ b2xDc1=S[+sLb4] 3. Sb7xLa5[+wBc2] e5xBd4[+sLa5]+ 4. a5xLb6
play all play one stop play next play all
Michel Caillaud: cooked by Dmitry Baibikov :
3.Sb7xLa5(+wBa3) Kb4xPb5(+sLa5)+ -4.Ta5xLa4(+wSd3)+ e5xSd4 (2022-07-19)
Kevin Begley: correction: P1404688 (2022-09-27)
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comment
Keywords: Circe (Parrain), Last Moves? (7), Valladao Task
Genre: Retro, Fairies
FEN: 8/8/PPp5/NkP5/RbP5/PBpN4/P4PP1/B1n2RK1
Input: Gerd Wilts, 2004-07-03
Last update: Kevin Begley, 2022-09-27 more...
26 - P1066741
Tomislav Petrovic
R033 Probleemblad 11-12/1998
Ing. R. Tomasevic gewidmet
P1066741
(14+10) C+
h#2 (AP)
1. gxf3ep 0-0-0 2. gxh1=T gxh4#
play all play one stop play next play all
White PCs: axb=, bxc=, dxexf, cxdxe
Black PCs: fxg2. wRh was captured by officer in cage, and since wK didn’t move wRg5 is promoted
A.Buchanan: Suppose White: dxexf,cxdxe,bxc=,a| Black: fxg. This means there is one capture by white unaccounted for. So can’t White have just played e.g. QxS? What am I missing? (2022-03-22)
Mario Richter: Regarding the "can’t White have just played e.g. QxS?-question", the following considerations may be helpful:
1. black Pawn f3 x Yg2 can only be retracted after wPf2 has returned home.
2. If at this moment the black K is still on g1, Y cannot be a white rook.
3. Assuming that W can still castle, wRg5 must be a promoted Piece, since wKe1+wPf2+wPg3+wPh2 form a cage from which the originalwRh1 could not escape ...

I think the same considerations can also be useful by answering the question about +sBc6 ... (2022-03-22)
A.Buchanan: Hi Mario, thanks I agree (2022-03-22)
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comment
Keywords: a posteriori (AP) (Type Petrovic), En passant as key, Castling (wg), Valladao Task, Promotion (t)
Genre: Retro, h#
Computer test: HC+ Popeye v4.87 & retro-logic
FEN: 1B6/p2p4/1p4Q1/5PRN/4PPpb/3Np1Pp/4P1pP/R3KbkB
Input: Gerd Wilts, 2004-09-16
Last update: A.Buchanan, 2023-09-11 more...
27 - P1068490
Kostas Prentos
Andrey Frolkin

13077 Die Schwalbe 219 06/2006
Werner Keym gewidmet
1. Preis
P1068490
(10+14) C+
BP in 26.0
1. h4 a5 2. h5 a4 3. h6 a3 4. hxg7 h5 5. g4 Sh6 6. g8=L Lg7 7. g5 Ld4 8. g6 f6 9. Ld5 Lc5 10. Lc6 0-0 11. g7 Kh7 12. g8=T bxc6 13. Tg5 La6 14. Te5 fxe5 15. f4 Tf6 16. f5 Td6 17. f6 Lc4 18. f7 Lxa2 19. f8=D Le6 20. Df3 a2 21. Dd5 axb1=S 22. Ta2 Sc3 23. dxc3 cxd5 24. Kd2 d4 25. Kd3 Lf5+ 26. e4 dxe3ep+
play all play one stop play next play all
The first known example of the Keym Task.
Henrik Juel: Stelvio 1.31 found the solution immediately and tested it unique in 9 minutes (for the first 25.0 moves) (2023-06-13)
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Keywords: Unique Proof Game, Ceriani-Frolkin Theme (DTLs), Castling, En passant, Valladao Task, Promotion (LTDs), Allumwandlung, Keym Task (The first known prob)
Genre: Retro
Computer test: Natch 3.1 (38 m, utilizing the final ep). Stelvio 1.33, 2min (retracting the e.p. move itself, so full C+)
FEN: rn1q4/2ppp2k/3r3n/2b1pb1p/8/2PKp3/RPP5/2BQ1BNR
Input: Gerd Wilts, 2006-08-05
Last update: Reto, 2023-06-13 more...
28 - P1069093
Michael Grushko
1623 The Problemist Supplement 05/2006
P1069093
(15+12) C+
BP in 10.5
1. a4 e5 2. a5 Dg5 3. a6 Sf6 4. axb7 Sa6 5. b8=S Lb7 6. Sc6 dxc6 7. h4 0-0-0 8. hxg5 Td3 9. exd3 Se4 10. Dg4+ f5 11. gxf6ep+
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A.Buchanan: 11. ... Kb8! is sound, moving past the diagram check. (2021-07-31)
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comment
Keywords: Unique Proof Game, En passant, Ceriani-Frolkin Theme (s), Valladao Task (wws), Promotion (S), Castling (sg)
Genre: Retro
Computer test: Euclide 0.93
FEN: 2k2b1r/pbp3pp/n1p2P2/4p3/4n1Q1/3P4/1PPP1PP1/RNB1KBNR
Input: Gerd Wilts, 2007-01-07
Last update: A.Buchanan, 2021-05-26 more...
29 - P1079607
Igor Vereshchagin
29 Zadachi i etyudy 14, p. 52-53, 1997
3. Lob
Thematurnier "Uschol-Prischol-Vernulsa"
P1079607
(6+15)
h#3 (AP)
1. cxb3ep 0-0-0 (T~?,L~?) 2. Dxd2+ Kxd2 3. La1 Txa1#
play all play one stop play next play all
im Kongreßbuch St. Petersburg 1998 nur Nachdruck im Kapitel "Aus dem Schaffen der Kongreßteilnehmer"

Das Originaldiagramm in 'Zadachi i etyudy' ebenso wie der Nachdruck im Kongreßbuch St. Petersburg 1998 haben einen sTd8, aber der begleitende Lösungstext erwähnt im Zusammenhang mit der Frage, ob zuletzt axb3,cxb3 oder cxb6 möglich war, daß auf dem Brett folgende schwarze Steine stehen: eine Dame, zwei Türme, zwei Springer, der schwarzfeldrige Läufer und 8 Bauern.
Also offensichtlich Diagrammfehler, und sSd8 ist korrekt.
Ladislav Packa: Why NL? Castling is a posteriori proof for e.p.! (2018-08-28)
A.Buchanan: Why not a3xSb4 or c3xSb4 as last move? Where is the promotion? (2018-08-28)
VL: Yes, it definitely looks as AP (with thematic illegal castling avoiding tries). I suspect missing two b knights somewhere: "superfluous" similarly to the b rooks...
wBa5 proves to be a promotee. Bl to move of course. (2018-08-29)
A.Buchanan: I agree with VL. WinChloe adds sSh1 & sTd8 (the latter is illegal with 8sB+2sT on the board already). If we add sSh1d8, then the problem is sound forwardly and retroly. The missing light sL can't just have been captured. (2022-05-24)
Mario Richter: Adding black Sh1+Sd8 is correct: obviously the original diagram is misprinted, the accompanying solution text speaks of: one black Queen, two black Rooks, TWO black Knights, one black dark-squared Bishop and 8 black Pawns. (2022-05-24)
A.Buchanan: Issue with animation (2022-05-25)
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Keywords: Valladao Task, En passant as key, Castling (wg), Promotion (L), a posteriori (AP) (Type Petrovic)
Genre: h#, Retro
Computer test: HC+ Popeye v4.87 & simple retro-logic
FEN: 3n3b/1p5p/1P1p2p1/Bp6/kPp1p2r/3p3r/q2P4/R3K2n
Reprints: WCCC St. Petersburg 1998
Input: hpr, 2008-10-26
Last update: A.Buchanan, 2023-07-30 more...
30 - P1089671
Aleksandr Azhusin
2 Shakhmaty v SSSR 1975
P1089671
(7+8)
#2
1. e4! droht 2. a8=D#,T#
1. ... fxe3ep 2. De5#
1. ... 0-0 2. Dg7#
1. ... Dxe4 2. Dxh8#
play all play one stop play next play all
Henrik Juel: C+ Popeye 4.61 (2022-06-17)
comment
Keywords: Valladao Task, En passant, Castling, Promotion, Promotion key
FEN: 4k2r/P1pR4/1N6/6p1/5p2/2Q3r1/4P3/K4Rnq
Input: Ivan Antonov, 2009-08-04
Last update: James Malcom, 2022-06-17 more...
31 - P1106801
Enzo Minerva
1927 Best Problems 43 2007
P1106801
(13+16) C+
BP in 13.5
1. d4 e5 2. Lh6 Dh4 3. Dd2 g5 4. Da5 Lxh6 5. Sc3 Kf8 6. 0-0-0 g4+ 7. f4 gxf3ep+ 8. Td2 fxe2 9. Sf3 e1=L 10. Kd1 Lg3 11. Tf2 Lc1 12. Ld3 h6 13. Lh7 e4 14. Ke1
play all play one stop play next play all
paul: Theme Valladao (2013-09-12)
James Malcom: An excellent Valladao with a castling paradox and Anti-Pronkin! (2021-01-23)
A.Buchanan: Normally, castling paradox would employ *both* K&R heading back home after the dalliance. There's non-standard material which to me seems a defect in a Valladao. No-one here was able to agree on what Anti-Pronkin is, so the term has been retired. I guess it covers everything which is not a Pronkin: from Allumwandlung to Zilahi :-) (2021-05-19)
Michel Caillaud: Anti-Pronkin (from FIDE Album "Theme definitions") :
A promoted piece is captured. The corresponding piece of the same colour from the game-array moves onto the promotion-square.
So 1) it doesn't cover everything which is not a Pronkin 2) it is not present in this problem (2021-05-21)
A.Buchanan: I was confusing the term with "Anti-Phoenix" oops.
As Michel says, this problem does *not* show Anti-Pronkin as per Michel's FIDE definition. The promoted piece is never captured.
The "Pronkin" theme in the V&V Encyclopaedia wisely does not requires that the original unit is captured. There has to be some credit for a unit reaching a thematic target square at all, irrespective of the fate of the unit. In the current problem, we could still imagine a Prenix after Lc1 for example to regularize the material: why couldn't that still class as Anti-Pronkin?
Unit quests & regularization of material should be keyworded separately. And there should be a proper symmetry between Pronkin & Anti-Pronkin themes, imho. (2021-07-31)
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Keywords: Unique Proof Game, Valladao Task (slwwg), En passant, Promotion (l), Castling, Non-standard material (l)
Genre: Retro
FEN: rnb2knr/pppp1p1B/7p/Q7/3Pp2q/2N2Nb1/PPP2RPP/2b1K2R
Input: Gerd Wilts, 2010-06-04
Last update: A.Buchanan, 2021-07-31 more...
32 - P1108561
Werner Keym
Allgemeine Zeitung Mainz 1968
P1108561
(15+4)
#2
1. 0-0-0? (illegal) c5/g1=D,T 2. Lxd5#
1. ... c6 2. Td4#
1. exd6ep+! c6 2. Lxc6#
play all play one stop play next play all
Henrik Juel: All captures were made by pawns
The black capture was h3xDg2 early in the game
The castling is illegal, because Black promoted on a1 (2020-12-31)
comment
Keywords: Cant Castler, En passant as key, Valladao Task
Genre: Retro, 2#
FEN: B7/2p1P1P1/5R1N/3pP3/1B2kP1P/4P1P1/2N1P1p1/R3K3
Input: Gerd Wilts, 2010-06-25
Last update: James Malcom, 2020-12-31 more...
33 - P1184196
Werner Keym
feenschach 183 2010
Hans Gruber zum 50. Geburtstag gewidmet
P1184196
(12+15)
#2
Die letzten Züge waren g7-g5 g6xLh7. Daher 1.h5xg6 e.p.! 0-0-0 2.a8D#.
play all play one stop play next play all
Das ist der erste (korrekte) Zweizüger mit den konsekutiven Spezialzügen En passant-Schlag, Rochade und Umwandlung (Valladao). (vgl. P1080516 (inkorrekt) und P1184197)
Henrik Juel: C+ Popeye 4.61 and analysis (2022-09-11)
comment
Keywords: Valladao Task
Genre: Retro
FEN: r3k3/P2p3P/pp1P1p1p/3p2pP/6nq/4bPrR/1P2PpRB/5BnK
Input: Gerd Wilts, 2011-01-06
Last update: Rainer Staudte, 2022-09-11 more...
34 - P1186997
Erich Bartel
5552 Problemkiste (138) 12/2001
P1186997
(4+4) C+
h=3 (AP)
0.1...
1. ... hxg6ep 2. 0-0 g7 3. Kh7 gxf8=D=
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Wenn ep erlaubt sein soll, dann muß g7-g5 der letzte Zug gewesen sein. Dies wiederum bedingt, daß sK+sT noch nicht gezogen haben. Nur unter dieser Betrachtungsweise (AP) ist das Ding korrekt.\eb
Löserstimmen:
Diese AP-Idee ist ja nun hinlänglich bekannt, aber man muß auch darauf kommen, sie für den Valladao zu nutzen. Finde ich prima (MN).
ep, und dann kann Schwarz auch noch rochieren (HM).
Wenn g7-g5 letzter Zug war, darf Schwarz noch rochieren (KF)...
AP (= a posteriori) argumentiert andersrum: wenn Schwarz noch soll rochieren dürfen, muß g7-g5 der letzte schwarze Zug gewesen sein (\eb)
Unlösbar! Der Autor meint wohl, man könnte mit 1. ... hxg6ep 2. 0-0 loslegen; hier irrt Goethe. Die beiden Konventionen -ep-Schlag nur, wenn Zulässigkeit retroanalytisch beweisbar ist; Rochade stets, außer wenn Unzulässigkeit retroanalytisch beweisbar ist- sind zwar passend verknüpft. Was aber den Vorrang hat, zeigt die zeitlich Reihenfolge der Anwendung. Zuerst kommt der ep-Schlag, und diesbezüglich gilt: Zulässigkeit nicht beweisbar, also nicht erlaubt (LZ).
Lieber Herr Zagler, vielen Dank für Ihren Kommentar, aber ich denke nicht, daß dazu eine Stellungnahme erforderlich ist, denn dazu ist schon viel diskutiert und geschrieben worden, ichverweise nur auf G. Lauingers "a posteriori Zwischenbilanz" in feenschach (80) X-XI 1986, S.414 ff, wo die AP-Regelung allgemein wie folgt definiert wurde:
"Eine einleitende Handlung (z.B. ein ep-Schlag oder ein unkonventionell Beginn), deren Zulässigkeit nach gültigen Konventionen zunächst nicht nachgewiesen werden kann, wird im Verlauf der Lösung(en) nachträglich durch einen oder mehrere Sonderzüge legalisiert. Legalisieren bedeutet dabei, daß _nur_mit_der_Ausführung_ des Sonderzuges (der Sonderzüge) dessen (deren) Zulässigkeit nachgewiesen wird und gleichzeitig (i.a. aus retroanalytischen Gründen) damit auch nachträglich die Zulässigkeit der einleitenden Handlung."
Ob Sie nun mit dieser Regelung einverstanden sind hat für o.a. Aufgabe wenig Bedeutung, denn nach o.a. "AP"-Definition ist sie lösbar. Wenn Sie "AP" so nicht akzeptieren und einer anderen Retro-Philosophie zugetan sind, steht das auf einem anderen Blatt. Da müßten Sie sich dann mit den entsprechenden Experten auseinandersetzen. (\eb)
Da nur die Rochade den sK nach h7 zu manövrieren vermag, fällt manchem sicher gar nicht erst auf, daß allein sie (neben dem Autor, natürlich!) für die Legalisierung des e.p.-Schlages verantwortlich ist (MR).
Valladao-Task. Bei dieser Ausgangsstellung mit Ansage (HL).

Versions at P1382816 & P1276701
A.Buchanan: Removing the superfluous sBf7 adds various non-castling lines which the AP convention duly protects us from, and makes the composition a sound miniature (2020-10-03)
comment
Keywords: Valladao Task, Castling, En passant as key, Promotion, a posteriori (AP) (Type Petrovic)
Genre: Retro, Fairies
Computer test: %Popeye FreeBSD-4.3-RELEASE-32Bit-Version 3.73
FEN: 4k2r/5p2/5P1P/5KpP/8/8/8/8
Reprints: Springaren (116) 03/2010
K3966 Problemkiste (199/200) 03/2012
Input: Erich Bartel, 2011-02-09
Last update: A.Buchanan, 2022-03-21 more...
35 - P1216201
Alexandr P. Dmitrenko
121 Problemist Yuga 07-12/1997
P1216201
(13+6)
s#9
1. d8=S! Th8 2. 0-0-0 Th7 3. Tb1 Th8 4. Se7+ Kxf8 5. Se6+ Kxe7 6. Dc5+ Kf6 7. Lh4+ g5 8. fxg6ep+ Kxe6 9. Dc8+ Txc8#
play all play one stop play next play all
SCHRECKE: C+, Gustav 4.2e, Brute Force (2023-08-11)
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comment
Keywords: Valladao Task
Genre: s#
FEN: 1R3Nk1/3P2pr/6Np/5P1B/5P2/p3p1B1/P1Q1P3/R3K3
Input: Frank Müller, 2011-10-29
Last update: Olaf Jenkner, 2020-03-11 more...
36 - P1224980
Paul Raican
T12v ChessProblems.ca 06/06/2010
D. Meinking & G. Donati gewidmet
Spezialpreis (version)
P1224980
(10+9)
pSer-h-dia 41
1. b4 ... 2. b5 ... 3. b6 ... 4. bxa7 ... 5. axb8=S ... 6. Sxd7 ... 7. Sxf8 ... 8. Sxh7 ... 9. Sf6+ Kf8 10. Sd5 ... 11. Sxe7 ... 12. Sg6+ fxg6 13. La3+ Txa3 14. Sxa3 ... 15. Sb1 ... 16. a4 ... 17. a5 ... 18. a6 ... 19. a7 ... 20. a8=D ... 21. Da3+ c5 22. Df3+ Ke8 23. Dc6+ bxc6 24. f4 ... 25. f5 ... 26. f6 ... 27. f7+ Kd7 28. f8=S+ Kc7 29. Ta7+ Kb6 30. Ta6+ Kb5 31. e4+ c4 32. Sc3+ Kc5 33. d4+ cxd3ep 34. Dh5+ Kd4 35. Sge2+ dxe2 36. De5+ Ke3 37. Sd1+ exd1=S 38. Le2 ... 39. 0-0 ... 40. Kh1 ... 41. Tg1 Sf2#
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Dan Meinking: The original version (wSf8 on e6; wDe5 on h5) was cooked by Mario Richter and "rawbats": 1.a4 2.a5 3.a6 4.axb7 5.b7xa8=S 6.Sb6 7.Sxd7 8.b4 9.b5 10.b6 11.bxa7 12.a8=D 13.La3 14.Lxe7 15.Sxf8 16.Sxh7 17.Da4+ Sd7 18.Sc3 19.Sd5 20.Sf8 21.Sf6+ Kxe7 22.Sg6+ fxg6 23.Db4+ Kxf6 24.Df8+ Ke6 25.Ta6+ c6 26.d4 27.f4 28.De7+ Kf5 29.e4+ Kxf4 30.Dd6+ Se5 31.Dh5 32.Se2+ Ke3 33.Sf4 34.Le2 35.0-0 36.Kh1 37.Da3+ Kxd4 38.Dd6+ Ke3 39.Dd3+ Sxd3 40.Se6 41.Tg1 Sf2#. The diagram and solution have been updated to reflect Paul's correction. (2012-06-24)
paul: This version is published in Quartz50/2020. (2022-03-30)
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comment
Keywords: Parry Series, Unique Proof Game, Valladao Task
Genre: Fairies, Retro
FEN: 2bq1Nnr/6p1/R1p3p1/4Q3/4P3/4k3/2P1BnPP/6RK
Input: Dan Meinking, 2011-11-16
Last update: A.Buchanan, 2018-05-04 more...
37 - P1228018
Enzo Minerva
Andrew Buchanan

Introduction to Proof Games 01/2010
EM, version AB
P1228018
(14+14) C+
Proof game in 9.0
1. e4 f5 2. Lb5 f4 3. Se2 f3 4. 0-0 fxe2 5. e5 exf1=L 6. Dg4 Lc4 7. d3 Kf7 8. Dxc4+ d5 9. exd6ep+ Le6
play all play one stop play next play all
Shortest known proof game showing Valladao-Monteiro (after 8.5 moves - the extra half-move is to move beyond the check, and is the only move which preserves uniqueness of the PG).
Composed for http://abrobecker.free.fr/chess/IntroductionToPGs.pdf
>>> Agreed with Enzo Minerva that this is EM v AB: 24-Dec-2014. (Original is at P1284755.)
Kevin Begley: Partially anticipated, by Enzo Minerva, Best Problems 2005 (which shows Valladao-Monteiro in as many moves, based upon the same idea). (2014-03-01)
A.Buchanan: Thanks for highlighting this, Kevin. I had searched PDB for prior art before composing this one, but Enzo's problem was (and still is) absent. I feel that my little composition does add something more. In mine, the identity-defining Ceriani-Frolkin bishop move is not a capture. And WQ has potentially three routes to its final square, including the CF promotion square, but the two duals are eliminated by the waiting move d3. So, is Enzo still active? I am thinking this partial anticipation probably a case of "AB after EM" but if Enzo is still around I would like to discuss with him out of courtesy. (2014-05-01)
Kevin Begley: Andrew, at best, I see yours as a version. (2014-05-01)
Kevin Begley: Compare to 'P1284755'. Clearly Andrew's version is better (and not only because of the extra move avoiding check in diagram -- which may be forgiven in a proofgame aiming specifically for brevity), however thematically, they are nearly indistinguishable. I leave it for Andrew and Enzo to collaboratively determine the proper credit here. (2014-05-01)
A.Buchanan: Oh for Pete's sake... there's *another*, now I look in WinChloe:
Alexeï GASPARYAN Oakham PG Tourney,
The Problemist Supplement 2009-10
1° Mention d'Honneur.
rnb2rk1/pp1p1ppp/3p4/2q5/1b6/3p4/PPP1PKPP/RNBQ1BNR
PG in 9.0
1.f3 e5 2.f4 Bb4 3.f5 Ne7 4.f6 00 5.f×e7 e4 6.e8=N Qg5 7.Nd6 c×d6 8.Kf2 Qc5+ 9.d4 e×d3ep+ (C+)
Now the date in WinChloe is wrong: what counts is the closing date for the tournament, 31-12-2009 (although the judging was only held in 07-2010, and publication was in 11-2010). Mine was published in 01-2010 (composed on 10-01-2010. I think I fold at this point, and allow Messrs. Minerva & Gasparan to duke it out, if they care. (2014-05-04)
A.Buchanan: @Kevin: and on the subject of versioning. Do you have a link to anything that gives guidelines to relative attribution. The Codex is sketchy (as usual), and I don't know where else to look. (2014-05-04)
Henrik Juel: On versioning:
When inspired by a published problem by AA to improve it, I would write 'hj after AA' if my contribution is large and 'AA, version by hj' is it is small. Of course, 'improve', 'large', and 'small' are not well defined, so it is up to the improver and the editor what to choose, and up to the judge whether an award is warranted.
In the Minerva-Gasparyan-Buchanan case the later authors surely were not inspired by the first, so here I would suggest the following possibilities: anticipated, partially anticipated, and not anticipated, again leaving the final verdict to the judge (2014-05-04)
A.Buchanan: I don't see any fundamental difference between accidental and deliberate partial anticipation. Ultimately the choice is between labeling the problem as "A,version", "A,version B" or "B, after A". I am totally ok with whatever Minerva/Gasparyan eventually determine. However, I don't think that PDB supports "A, version B" currently. (2014-05-05)
A.Buchanan: Not heard anything from Messrs Minerva or Gasparyan. I should rephrase my earlier statement as: "I don't see any fundamental difference between accidental partial anticipation, and acknowledged deliberate versioning, in terms of the set of possible final outcomes." (2014-12-24)
A.Buchanan: Resolved with Enzo :D! (See above!) (2014-12-24)
A.Buchanan: Resolved with Alexey in Facebook yesterday :D! AB: "I would like to ask you: are you ok with the current attribution of my problem?" AG: "Yes I agree." So there we are. Maybe EM & AG will conduct diplomatic negotiations at some point, but that's not my concern :) (2021-10-05)
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comment
Keywords: Valladao Task (swwk), Unique Proof Game, Ceriani-Frolkin Theme (l), Prentos Theme (l), En passant, Castling, Promotion (l)
Genre: Retro
Computer test: Euclide 0.99
FEN: rn1q1bnr/ppp1pkpp/3Pb3/1B6/2Q5/3P4/PPP2PPP/RNB3K1
Reprints: 11 Introduction to Proof Games 03/2010
Input: Alain Brobecker, 2011-12-26
Last update: A.Buchanan, 2021-05-26 more...
38 - P1233676
Sergio Orce
5421 Problemkiste (136) 08/2001
P1233676
(12+10)
#2
(RV)
b) wBb3->b4
a) 1. Ke6! (0-0-0 illegal!) ... 2. h8=D,T#
b) 1. dxe6ep! 0-0-0 2. Dxb7#
oder 1. Ke6 ... 2. h8=D,T#
play all play one stop play next play all
a) 0-0-0 ist illegal. Die wBB haben 5-mal geschlagen, wBBf3/h3 also nicht.
-> sBf2h2 haben 3-mal geschlagen, entweder 3-mal auf schwarz oder nach Rücknahme von g2-g4
-> Lf1 ist nicht unter den Schlagopfern.
-> wBa2 mußte umwandeln. Falls 0-0-0 noch gehen soll, muß die UW auf h8 geschehen sein
-> letzter Schlagfall W×S ist sowieso klar
-> sBa7 muß als Schlagfall für wB dienen. Da e5 es selbst nicht kann, muß er umgewandelt haben, kann dazu aber nur wLf1 schlagen
-> Widerspruch. -> 0-0-0 ist illegal.
b) dito, aber es geht sBa7-a4xLb3-b1 usw.
-> 0-0-0 ist legal. Aber nur, wenn zuletzt e7-e5.
-> 1. dxe6ep, oder falls zuletzt sK/sT-Zug 1. Ke6.
-> "Retrovarianten" (RV) wohl besser als "A posteriori" (AP)
(Übersetzung, Anmerkung und Prüfung durch Hans Gruber).
A.Buchanan: The retro content here is fun, but I don't see why it's suggested that this is AP. (a) is a cant castler, and (b) is a standard PRA matrix. Removing AP as a keyword for this one. (2023-07-21)
comment
Keywords: Valladao Task, Castling, En passant as key, Partial Retro Analysis (PRA)
Genre: Retro, 2#
FEN: r3k3/1pp4P/3p2N1/2NPpK2/4QpP1/1P3PRP/4Pp1p/6n1
Input: Erich Bartel, 2012-03-04
Last update: A.Buchanan, 2023-07-21 more...
39 - P1235136
Manfred Nieroba
K3965 Problemkiste (199/200) 03/2012
P1235136
(2+5) C+
h#2.5 (AP)
Circe
1. ... exf6ep[+sBf7] 2. 0-0 fxe7 3. Kh8 exf8=D#
play all play one stop play next play all
In the usual way with Circe, can refute the idea that Black just captured, so if Black can castle, White can ep. So AP Type Petrovic triggers. No retro try, and no set play.
more ...
comment
Keywords: Valladao Task, Circe, En passant as key, Castling, a posteriori (AP) (Type Petrovic), Minimal, Miniature
Genre: Fairies, h#, Retro
Computer test: HC+ Popeye 4.61 and analysis
FEN: 4k2r/4p2p/8/4PpK1/8/8/8/8
Input: Erich Bartel, 2012-03-25
Last update: A.Buchanan, 2022-06-07 more...
40 - P1235808
Martin Walter
12171 Die Schwalbe 205 02/2004
P1235808
(5+7+1)
s#4
Längstzüger
Anticirce
1. a4+ bxa3ep[+nBa7] 2. a8=nT Txh8 3. Da6+ Kxa6[+sKe8] 4. Kxg1[+wKe1] 0-0#
play all play one stop play next play all
Steen Christensen: ... 4.Kxg1[Kh1] \oo\# should read ... 4.Kxg1[Ke1] 0-0# (2013-03-12)
SCHRECKE: C+, popeye 4.87 (2022-01-09)
more ...
comment
Keywords: Valladao Task, Maximummer, Circe (Anti), En passant, Castling, under-promotion
Genre: Fairies
FEN: 7B/8/4Q3/1kp5/1-P5p/4p3/P3P3/n4Knr
Reprints: F4 König & Turm (14), p. 57, 09/2004
Input: Erich Bartel, 2012-04-03
Last update: Alfred Pfeiffer, 2017-07-15 more...
41 - P1263387
Ralf Krätschmer

3. Klein-Winsener Rochade-TT
P1263387
(9+10)
#6
1. 0-0-0? droht 2. Th1#
1. ... La3#

1. h8=S! Sxh8 2. Ld8+ g5 3. fxg6ep+ Tg5 4. 0-0-0 La3+ 5. Kb1 ... 6. Th1#
play all play one stop play next play all
SCHRECKE: C+, Gustav 4.1d, Brute Force (2021-06-05)
comment
Keywords: Berlin Theme, Castling, Promotion (S), En passant, Valladao Task
Genre: n#
FEN: 8/2B2npP/3p3p/1r3P1p/1b3P1k/2p3p1/2P1B1P1/R3K3
Input: Felber, Volker, 2013-02-26
Last update: James Malcom, 2021-06-05 more...
42 - P1276697
Peter Heyl
15592 Schach 11/2004
P1276697
(12+9) C+
#3
1. gxh8=D? bxc4!
1. Td1? bxc4!

1. 0-0-0! droht 2. Td6+ exd6 3. exd6#
1. ... f5 2. exf6ep Kf7 3. Txe7#
1. ... bxc4 2. Lf1 Ta4 3. d8=S#
play all play one stop play next play all
Henrik Juel: C+ Popeye 4.61 (2020-09-25)
comment
Keywords: Valladao Task
Genre: 3#
FEN: r5br/3PppP1/2P1k1p1/1pP1P1P1/2P1R1P1/p6B/8/R3K3
Input: Felber, Volker, 2013-08-22
Last update: James Malcom, 2020-09-25 more...
43 - P1287896
Jelisej K. Lebedkin
68 Die Schwalbe 29, p. 213, 10/1974
Preis, 154. TT., Abt. 3
Richter: H. P. Suwe
P1287896
(12+7) cooked
#3*
* 1. ... Sa3-c2+ 2. Db2xc2 droht 3. Dc2-g6#, 3. Dc2-f5#
2. ... f3-f2+ 3. Dc2xf2#
1. Th2-h4? droht 2. Th4-f4#
1. ... e7-e5!
1. 0-0-0! droht 2. Db2-b6 ... 3. Db6-g6,Db6-e6#, 2. Td1-f1 ... 3. Tf1xf3#
1. ... e7-e5 2. dxe6ep+ Kf7xe6 3. d7-d8=S#
1. ... g7-g5 2. hxg6ep+ Kf7xg6 3. h7-h8=S#
1. ... g7-g6 2. h5xg6+ Kf7xg6 3. h7-h8=S#
play all play one stop play next play all
Cook: NL:
1.Db2-b6 ! Drohung: 2.Db6-g6 # 2.Db6-e6 #
1...Sa3-c2 + 2.Ke1-d2 Drohung: 3.Db6-g6 # 3.Db6-e6 #
Von der NL mal abgesehen, dieser Wust von Nebenvarianten und "Verführungen" machen das Stück für meinen Geschmack schon fast zum Ärgernis. \eb 16.1.2001

'Die Schwalbe', Heft 33 (Juni 1975), S. 341: "Nr. 68/Lebedkin hat nach 1. ... e5 den Dual 2. Dxe5 und zu dem die NL 1. Dd6! [gemeint war wohl 1. Db6!].
Die Auszeichnungen der inkorrekten Aufgaben entfallen. Ein Nachrücken nachfolgender Preisprobleme an die Stelle entfallener Aufgaben findet nicht statt."
milan: m.j.frelih::sBb7 nach a7 1.0-0-0! (2014-09-14)
James Malcom: Is it possible that the bP on b7 was a misprint and it should have been on a7? Because it seems very bizarre that such an obvious cook could slip into an awarded problem. (2020-09-26)
comment
Keywords: Valladao Task, En passant, Castling
Genre: 3#
FEN: 2N2b2/1p1PpkpP/8/3P3P/8/n3BpN1/1Q4PR/R3K3
Input: Erich Bartel, 2014-09-10
Last update: Mario Richter, 2020-09-26 more...
44 - P1287941
Klaus Wenda
Heinrich Bernleitner

4123 diagrammes (127) 10-12/1998
P1287941
(11+6)
s#12
Längstzüger
1. a8=T+ Kd7 2. e8=L+ Ke6 3. f8=S+ Kf5 4. c8=D+ Se6 5. 0-0-0 Ke4 6. Dxc6+ Kf5 7. g4+ fxg3ep 8. Df3+ Sf4 9. Lb5 axb5 10. Ta1 bxc4 11. Tb1 cxb3 12. Dd3+ Sxd3#
play all play one stop play next play all
Korrektur
paul: Correction of P0009099. (2022-04-06)
comment
Keywords: Valladao Task, Allumwandlung, Maximummer, En passant, Castling
Genre: Fairies
FEN: 2k5/P1P1PP2/p1p3p1/6n1/2P2p2/1R5P/3P2P1/R3K3
Input: Erich Bartel, 2014-09-11
Last update: Alfred Pfeiffer, 2014-09-11 more...
45 - P1287950
Hilmar Ebert
33 Stern 08/08/1991
P1287950
(6+3) C+
#3
1. 0-0-0! d7-d5 2. cxd6ep e4-e3 3. c7-c8=D,T# (UW-Dual)
play all play one stop play next play all
Henrik Juel: C+ Popeye 4.61 (apart from the promotion mate dual) (2020-09-26)
comment
Keywords: Valladao Task, En passant, Castling key, Tolerated dual promotion
Genre: 3#
Computer test: Popeye 4.61
FEN: 8/2Pp4/8/N1P5/4p3/P1k5/8/R3K3
Input: Erich Bartel, 2014-09-12
Last update: Alfred Pfeiffer, 2020-09-26 more...
46 - P1288159
Alexandr P. Dmitrenko
Sachove umeni 2000
P1288159
(12+7) C+
s#9
1. a8=T! b5,b6 2. cxb6ep,cxb6 c5 3. Sxc5 Kf8 4. 0-0+ Kg8 5. Lf7+ Kf8 6. Dg7+ Ke7 7. Lg8 Kd8 8. Th1 Txg8 9. Dg5+ Txg5#
play all play one stop play next play all
Anton Baumann: 1. ... b6 2.cxb6 c5 3.Sxc5 ...
C+ Gustav 4.2a (2022-04-07)
comment
Keywords: Valladao Task, En passant, Castling
Genre: s#
FEN: 1b4kr/Pp1P3p/2p1N2P/2P1Q2B/2N4R/4p3/4P3/4K2R
Input: Erich Bartel, 2014-09-16
Last update: Marcin Banaszek, 2022-04-07 more...
47 - P1288169
Kjell Widlert
3027 Problemkiste (82) 08/1992
P1288169
(4+9)
h#2
Gitterschach
1. cxb3ep! (Tempo) Txg6 2. Le2 0-0#
2. ... Tf1+? 3. Kf2!
play all play one stop play next play all
Der letzte Zug war b2-b4
En passant als Tempozug. Die Grundidee (Einfachschritt des wB ist im Gitterbrett automatisch ausgeschlossen) kann man schon in Fairy Chess Review finden. Hier ist sie mit Rochade garniert in offener Stellung. die jedoch keinen anderen letzten Zug erlaubt. (Autor).
Ganz toll gemacht! (HB).
Raffinierter Zugzwang (KF).
Das ist schon gemein, was der Autor mit den Lösern vorhat (HM).
Viel Gitterschach (Doppelschritt, Retropatt des Tg7 und Rochade trotz Le2) läßt den bekannten e.p.-Trick in neuem Licht erscheinen (MR).
Henrik Juel: Where is the promotion needed for Valladao? (2024-02-04)
comment
Keywords: Valladao Task, En passant, Castling, Grid Chess
Genre: Fairies, Retro
FEN: 8/4p1R1/4p1p1/8/1Pp4p/2p2k2/2p5/3bK2R
Input: Erich Bartel, 2014-09-16
Last update: Olaf Jenkner, 2015-03-19 more...
48 - P1288199
Klaus Wenda
U188 König & Turm 04/2003
1. Lob
Informalturnier
Richter: Hans Gruber
P1288199
(10+9) C+
s#7
Längstzüger
1. 0-0-0 Lb4 2. h8=D+ Ke7 3. f8=L+ Kd8 4. b8=T+ Kc7 5. a8=S+ Kxb8 6. Dxg7 d5 7. exd6ep axb2,cxb2#
play all play one stop play next play all
more ...
comment
Keywords: Maximummer, Valladao Task, En passant, Castling, Promotion (DLTS), Allumwandlung
Genre: Fairies
Computer test: Alybadix
FEN: 5k2/PP1pbPpP/4pp2/4P3/4P3/p1p5/pRN5/R3K3
Input: Erich Bartel, 2014-09-18
Last update: James Malcom, 2021-12-13 more...
49 - P1288435
Manfred Nieroba
V5 Problemkiste (157) 02/2005
P1288435
(4+6) C+
h#1.5 (AP)
sDU=Grashüpfer
1. ... dxe6ep 2. 0-0-0 a8=D#
play all play one stop play next play all
Durch den ep-Schlag beweist Weiß, dass der letzte Zug von Schwarz
e7-e5 gewesen ist. Die sGG können mangels Bock nicht gezogen haben
und hätten sK oder sT gezogen, so wäre die {\ooo} nicht mehr
möglich (Autor).
A.Buchanan: sGh8 seems useless as it merely eliminates the thematic retro tries. What am I missing? I wonder if the composer really understood the nature of AP...? (2022-03-22)
more ...
comment
Keywords: Valladao Task, En passant as key, Castling, a posteriori (AP) (Type Petrovic), Promotion in the mating move (D)
Pieces: du = Grasshopper (G)
Genre: Fairies, h#, Retro
Computer test: %Popeye FreeBSD-4.3-RELEASE-32Bit-Version 3.81
FEN: r3k2*2q/P4*2q2/*2q2P4/3PpK2/8/8/8/8
Input: Erich Bartel, 2014-09-22
Last update: A.Buchanan, 2022-03-22 more...
50 - P1288499
Manfred Nieroba
6452 Problemkiste (159-160) 07/2005
P1288499
(3+4) C+
h#2 AP
0.1...
Strict-Circe
1. ... cxd6ep[+sBd7] 2. 0-0-0 a8=D#
play all play one stop play next play all
Der sSh8 kann wegen Schach zuletzt nicht gezogen haben. Er verhindert zudem NLen.
Mangels Schlagobjekt kann der sB nur von d7 gekommen sein (Autor).

t/nur Themazüge,
A.Buchanan: 1. ... Ke6 Tb8 2. axb8=D/T[-]#? won't work because under "strict" Circe, a capture can't take place at all if the rebirth square is occupied. (2022-05-23)
A.Buchanan: Pieces never leave the board in strict Circe. "Hotel California". The diagram position is hence illegal and it's interesting that one can nevertheless get some kind of retro logic going. It points out a generally unspoken difference between "local" & "global" illegality. (1) Can we reverse moves indefinitely, or do we get stuck in some kind of reverse pat? (Can't say "retropat", because that implies that it's only pat with one player to move, as Henrik explained to me a while back.) (2) If the answer is yes then can we get back to the game array? These are different questions, and problems like this one rely on local rather than global legality. (2022-05-24)
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comment
Keywords: Valladao Task, En passant, Castling, Circe (Strict), Promotion (D), a posteriori (AP) (Type Petrovic)
Genre: Fairies, h#, Retro
Computer test: %Popeye FreeBSD-5.3-RELEASE-32Bit-Version 3.81
FEN: r3k2n/P7/8/2PpK3/8/8/8/8
Input: Erich Bartel, 2014-09-26
Last update: A.Buchanan, 2022-05-26 more...
51 - P1288715
Bernd Schwarzkopf
A12 Problemkiste (169) 02/2007
P1288715
(4+3) C+
=5
AP-Priorität
1. dxc6ep 0-0-0 2. b7+ Kb8 3. c7+ Kxb7 4. cxd8=D Ka7 5. Dc8=
3. ... Ka7 4. cxd8=S Kb8 5. Ka6,Kb6=
play all play one stop play next play all
A.Buchanan: Guessing so-called "AP-Priorität" is a variant of AP whereby Black is forced to legitimize (or at least forbidden to rule out the possibility of legitimizing) the earlier e.p. (2020-10-03)
comment
Keywords: En passant, a posteriori (AP) (Type Petrovic), Castling, En passant as key, Promotion, Valladao Task
Genre: Retro, Fairies
Computer test: Popeye v4.85 + minor retro/AP thinking
FEN: r3k3/8/1P1P4/1KpP4/8/8/8/8
Input: Erich Bartel, 2014-09-29
Last update: A.Buchanan, 2022-03-21 more...
52 - P1288719
Ivan Bryukhanov

P1288719
(5+2) C+
s=8
1. g8=D+! Kh6 2. 0-0 h4 3. Df6+ Kh5 4. g4+ hxg3ep 5. Tf3 g2 6. Dh4+ Kxh4 7. Th3+ Kxh3 8. Dg3+ Kxg3=
play all play one stop play next play all
James Malcom: Source? (2021-02-14)
comment
Keywords: Valladao Task, En passant, Castling, Promotion (D)
Genre: Fairies
Computer test: %Popeye FreeBSD-5.4-RELEASE-i386-32Bit V4.06
FEN: 3Q4/6Pk/8/7p/8/8/6P1/4K2R
Input: Erich Bartel, 2014-09-30
Last update: James Malcom, 2021-02-14 more...
53 - P1288722
Arnold Beine
Best Problems 2005
3. Preis
L. Vitale Memorial
P1288722
(3+11)
h#19
Doppellängstzüger
1. a5 d4 2. c5 dxc6ep 3. Db6 cxb7 4. Dh6 bxc8=S 5. Dc1+ Ka2 6. Dh6 Sd6+ 7. Dxd6 Kb1 8. Dh2 Ka1 9. Db8 d5 10. Dh2 d6 11. Da2+ Kxa2 12. 0-0-0 dxe7 13. d5 Kb3 14. Td6 Ka4 15. Th6 Kb5 16. Ta6 Kxa6 17. g5 Kb5 18. Lh6 Kc6 19. Lf8 exf8=D,T (UW-Dual)
play all play one stop play next play all
Anton Baumann: abgesehen vom Umwandlungsdual C+ (Alybadix) (2023-03-28)
more ...
comment
Keywords: Valladao Task, En passant, Castling, Maximummer (Doppel-)
Genre: Fairies
FEN: r1bqkb2/ppppp1p1/8/3P4/8/8/3P4/K7
Reprints: A4387 Phénix (178), p. 7731, 11/2008
Input: Erich Bartel, 2014-09-30
Last update: Alfred Pfeiffer, 2014-09-30 more...
54 - P1301693
Gaspar J. Perrone
i076 Mirador (16) 06/2005
P1301693
(8+10)
hs=6
Madrasi
1. a6 axb1=S 2. a7 Sa3 3. a8=D b1=L 4. 0-0 c1=T 5. Lf5 Kc8 6. e4+ dxe3ep=
play all play one stop play next play all
Anton Baumann: NL: 1.Kd2 Dxh3 2.e3 Txh8 3.a6 Sd5 4.S5c3 Df1 5.a7 cxb1=L 6.a8=T+ Ke7 = weitere mit Zugumstellung (2022-04-06)
comment
Keywords: Allumwandlung, Valladao Task, Madrasi
Genre: Fairies
FEN: 3k3B/2p4r/8/PN6/3p1n2/5q1B/ppp1P3/bN2K2R
Input: Erich Bartel, 2015-04-20
Last update: Alfred Pfeiffer, 2015-04-21 more...
55 - P1329145
Gennady Koziura
Valery Kopyl

10860 feenschach 205 01-02/2014
P1329145
(13+6) C+
s#9
1. Sg6+! Sxg6 2. Th4+ Sf4 3. Th4-h5 Ld8-g5 4. Sc1-a2 b3xa2 5. b5-b6 c7xb6 6. d7-d8=L b6-b5 7. b2-b4 c4xb3ep 8. Dc6-c7 Ke5-d5 9. 0-0-0 Sf4-d3#
play all play one stop play next play all
more ...
comment
Keywords: Valladao Task, Castling, En passant, under-promotion (L)
Genre: s#
Computer test: Gustav 4.1d
FEN: 3b1N1n/2pP4/2Q5/1P2k3/2p2R2/1pP2P1B/1P5B/R1N1K3
Input: Frank Müller, 2017-01-02
Last update: Marcin Banaszek, 2021-04-01 more...
56 - P1359077
Joaquim Crusats
13 Internet 12/2018
2. ehrende Erwähnung
JT-Sergej-Volobujev-60
Abteilung Retro
P1359077
(11+14)
h#2.5 (AP)
1. ... fxg6ep 2. 0-0-0 gxf7 3. Te8 fxe8=D#
(+ hordes of tries that omit castling)

R: 1. ... g7-g5! 2. Lh1-g2 Lh3-f1 3. Se7-d5 Lf1-h3 4. Sg6-e7 Lh3-f1 5. Sh8-g6 Lf1-h3 6. h7-h8=S Lh3-f1 7. h6-h7 Lf1-h3 8. h5-h6 Lh3-f1 9. h4-h5 Lf1-h3 & e.g. 10.h2/h3-h4 h4xg3
play all play one stop play next play all
Link zum Preisbericht auf "http://www.selivanov.world/en/newss/detail.php?ID=1151"
Official solution text: This and the following tasks are connected by the search of retrogame, in which the position on the diagram allows the execution of moves that reach the goal (a posteriori).
1...f:g6 e.p. 2.0-0-0 g:f7 3./e8 f:/e8s# - the only solution with e.p. on the first move, leading to mate, requires preservation of the right to castling of Black. The problem is to prove that the position in the diagram is legal, provided that Black can castling and the last move was Black's g7-g5.
White's balance is closed: 11 + h:g3 + d:c2 + c:d + a:b + a-w! = 16
Black's balance closed: 14 + e:d3 + d:e4 = 16
Retro game: -1...g7-g5! -2.oh1-g2 +h3-f1 -3.me7-d5 +f1-h3 -4.mg6-e7 +h3-f1 -5.mh8-g6 +f1-h3 -6.h7-h8m +h3-f1 -7.h6-h7 +f1-h3 -8.h5-h6 +h3-f1 -9.h4-h5 +f1-h3 -10.h2/h3-h4 h4:Xg3 and the position is released. X is knight, bishop, or queen.
Retropositional play of the white knight and black bishop provides the possibility of ep. wPa2 is waylaid on the a-file. Example realization: 1. a4 d6 2. a5 Lh3 3. g4 Sc6 4. Ta3 Sxa5 5. Tg3 Sb3 6. Sf3 Sa1 7. Se5 a5 8. b3 a4 9. Sd3 a3 10. Sb2 axb2 11. Lg2 e6 12. Lf3 d5 13. Lg2 La3 14. b4 h5 15. Lf1 Th6 16. Lg2 Tf6 17. Lf1 Tf3 18. Lg2 Tb3 19. Lf1 e5 20. d3 e4 21. Le3 Sf6 22. f4 Sg8 23. Thg1 Se7 24. T1g2 Sg8 25. Tf2 Se7 26. Tff3 Sg8 27. Lg1 Se7 28. Lg2 Sg8 29. Lh1 Se7 30. f5 Sg8 31. Tf4 Sf6 32. Kf2 e3+ 33. Kf3 Se4 34. dxe4 c5 35. Lf2 c4 36. Lg1 c3 37. Sd2 cxd2 38. c3 d4 39. Dc2 d3 40. Lf2 dxc2 41. Lg1 Dd3 42. exd3 e2 43. Kf2 Lg2 44. Te3 Lh3 45. Kf3 Lf1 46. Lf2 h4 47. Le1 Lh3 48. Lg3 Lf1 49. h3 hxg3 50. h4 Lh3 51. h5 Lf1 52. h6 Lh3 53. h7 Lf1 54. h8=S Lh3 55. Sg6 Lf1 56. Se7 Lh3 57. Sd5 Lf1 58. Lg2 g5 59. fxg6 O-O-O 60. gxf7 Te8 61. fxe8=D#


Author's solution from Problemas reprint 2022: On previous occasions we have already dealt in these pages with the ep convention, which establishes that, for the first move in a direct problem to be a capture ep, it must be possible to demonstrate by retro analysis that the last move was the double pawn jump.
It may happen that this demonstration is subordinate to the fact that a certain castling right is preserved. In this case, for the ep capture to be legitimate, in the subsequent direct game castling must be performed, which will conclusively prove that the en passant capture was possible. The codex states that, in these situations, the stipulation should indicate that the capture en passant will be justified by the subsequent castling, which is indicated by the term "a posteriori" below the diagram. Problem 1, which we use as an example, illustrates this concept.
It is a helpmate, and we see that the first move is made by White. And, indeed, for checkmate to occur, the capture at the passage of the black pawn on g5 is necessary. There are several continuations that allow Black to checkmate, but we must not forget that Black must castle during the process and it is here that the solution becomes unique: 1...fxg6 e.p. 2.0-0-0 gxf7 3.Te8 fxe8=D# (in helpmate notation).
But problem 1 is mainly an exercise in retro analysis. We must show that, if Black maintains the castling right, his last move was ...g7-g5. Let us look at the balance of the pieces. There are 14 black pieces on the board and the two missing ones can be shown to have been captured with c~d (= "cxd & dxc") or d~e. Five white pieces are missing and were eaten as follows: the a2 pawn was eaten on its file (if Black keeps his castling rights) and the other four pieces with hxg3, axb, d~e or c~d respectively.
We must realize that to open the cage at the bottom we have to retract ...hxg3, but this is not going to be possible until the white pawn on the h-file has moved back to the origin. To do so, we must retract the following moves: -1...g7-g5! -2.Ah1-g2 Ah3-f1 -3.Ce7-d5 Bf1-h3 -4.CSg6-e7 Ah3-f1 -5.Ch8-g6 Bf1-h3 -6.h7-h8=C Ah3-f1 -7.h6-h7 Bf1-h3 -8.h5-h6 Ah3-f1 -9.h4-h5 Bf1-h3 -10.h2/h3-h4 h4xXg3 and the tangle unravels. There is a retro opposition between the white knight and the black bishop and, since the white knight must pass the g6-square to unpromote, if this square is occupied by the black pawn (in case the last move would have been -1...g6-g5), essential time is lost, and the reader can see that the cage cannot be opened. Thus it is demonstrated that, if Black retains his right to castle, his last move was -1...g7-g5 and, therefore, White can capture ep.
A.Buchanan: Sketch of solution: 7 units missing. Black captured axb & hxg. In addition there must be captures onto c,d&e files. These can't all be by White, so one was by Black which by file parity implies a 4th capture by a black pawn, but not a 5th. The other cde capture was by White, which implies another to cross-capture with. So WbcBde or WcdBde or WcdBef or WdeBbc or WdeBcd or WefBcd. But bc & cd can't cross-capture alone. So WcdBde or WdeBcd, I'm not sure which. wPh promoted, so can't retract h4xg3 any time soon. wPa was waylaid on a-file by some Black officer. The position must unlock by uncapturing wSh8. (2022-02-18)
Henrik Juel: White pawn captures: e2xd3 and d3xe4
Black pawn captures: a4xb3, cxd, d3xc2, and h4xg3; [Pa2] was captured by a black officer
The retroplay could be
R: 1... g7-g5 2.Lh1-g2 Lh3-f1, wSd5 unpromotes on h8 and the pawn retracts, while the black bishop pendulates on f1 and h3, 9.h4-h5 Lf1-h3 10.h2-h4 h4xLg3 11.Kf2-f3 Lg2-f1 12.Kg1-f2 Lh3-g2 13.Tf3-e3 e3-e2 14.e2xDd3 Dd8-d3 15.Tf1-f3 d2xDc2 16.Dd1-c2 Lg2-h3 17.c2-c3 Tc3-b3 18.Tf3-f4 b3-b2 19.Le5-g3 a4xSb3 etc. (2022-07-04)
James Malcom: I've taken the liberty to edit the text such that the PG in a recognizable format.

Here is the English notation of it: 1. a4 d6 2. a5 Bh3 3. g4 Nc6 4. Ra3 Nxa5 5. Rg3 Nb3 6. Nf3 Na1 7. Ne5 a5 8. b3 a4 9. Nd3 a3 10. Nb2 axb2 11. Bg2 e6 12. Bf3 d5 13. Bg2 Ba3 14. b4 h5 15. Bf1 Rh6 16. Bg2 Rf6 17. Bf1 Rf3 18. Bg2 Rb3 19. Bf1 e5 20. d3 e4 21. Be3 Nf6 22. f4 Ng8 23. Rhg1 Ne7 24. R1g2 Ng8 25. Rf2 Ne7 26. Rff3 Ng8 27. Bg1 Ne7 28. Bg2 Ng8 29. Bh1 Ne7 30. f5 Ng8 31. Rf4 Nf6 32. Kf2 e3+ 33. Kf3 Ne4 34. dxe4 c5 35. Bf2 c4 36. Bg1 c3 37. Nd2 cxd2 38. c3 d4 39. Qc2 d3 40. Bf2 dxc2 41. Bg1 Qd3 42. exd3 e2 43. Kf2 Bg2 44. Re3 Bh3 45. Kf3 Bf1 46. Bf2 h4 47. Be1 Bh3 48. Bg3 Bf1 49. h3 hxg3 50. h4 Bh3 51. h5 Bf1 52. h6 Bh3 53. h7 Bf1 54. h8=N Bh3 55. Ng6 Bf1 56. Ne7 Bh3 57. Nd5 Bf1 58. Bg2 g5 59. fxg6 O-O-O 60. gxf7 Re8 61. fxe8=Q#

Now, time to create a more streamlined PG... (2022-07-04)
James Malcom: 42.0 moves is optimal to reach the diagram; the proof speaks for itself, I believe: 1. a4 Nc6 2. a5 Nxa5 3. Ra3 h5 4. f4 Rh6 5. Nf3 Rc6 6. Ne5 Nf6 7. Rf3 Nb3 8. Nc4 Na1 9. Kf2 e5 10. Rg1 d5 11. b3 Bh3 12. g4 a5 13. Nb2 a4 14. f5 a3 15. Kg3 axb2 16. d3 Rc3 17. Bg2 Ba3 18. b4 Rb3 19. Bh1 c5 20. Bd2 c4 21. Be1 c3 22. Nd2 cxd2 23. c3 e4 24. Qc2 e3 25. Rf4 Ne4+ 26. dxe4 d4 27. Rgf1 d3 28. R1f2 dxc2 29. R2f3 Qd3 30. exd3 e2 31. Re3 h4+ 32. Kf3 Bf1 33. Bg3 hxg3 34. h4 Bh3 35. h5 Bf1 36. h6 Bh3 37. h7 Bf1 38. h8=N Bh3 39. Ng6 Bf1 40. Ne7 Bh3 41. Nd5 Bf1 42. Bg2 g5 (2022-07-04)
comment
Keywords: Valladao Task, Promotion in the mating move (D), a posteriori (AP) (Type Petrovic), En passant as key, Castling (sg)
Genre: h#, Retro
Computer test: Forward play Popeye v4.87 but retro play requires substantial thinking in order to establish retro-opposition. Believed to be sound.
FEN: r3k3/1p3p2/8/3N1Pp1/1P2PRP1/brPPRKp1/1pppp1B1/n4b2
Reprints: Problemas 07/2022
Input: Mario Richter, 2019-01-03
Last update: James Malcom, 2022-07-04 more...
57 - P1380122
Zalmen Kornin
Kibitzer's Cafe 5/8/2004
P1380122
(9+5) C+
#4
1. g8=D! d5 2. exd6ep Kc2 3. Sxc3 Kd3,Kb2 4. 0-0-0#,Dxa2#
play all play one stop play next play all
Final development of the earlier P1380121

https://www.chessgames.com/perl/chessforum.pl?kpage=587&archive=1#kibitzing

"For those interested in Chess Problems: In Tim Krabbé's "Open Chess Diary" the investigation on an idea in Composition, the so called "Belén-Theme" goes on with more novelties; - i'm arriving from that chess-cyber-café... i found that Problemist, he asked me "do You know the Valladão-Theme?" - Yes, i knew that jargon: "The Problem is pronto" What? "Ready" He showed me and asked me to publish here (is related to the previous ones) Author: Z. Kornin; "The Kibitzer's Café" 2004, Original - White: Ke1, Ra1, Bd4, Nb1, Pb6, Pc5, Pe5, Pg4, Pg7 (9); Black: Kc1, Pa2, Pc3, Pc6, Pd7 (5) - Mate in 4 , or in Forsyth: 8-3p2P1-1Pp5-2P1P3-3B2P1-2p5-p7-RNk1K3 (9+5) #4 < the key introduces a threat against 'a2', 'b3' and 'c4' , there are two related thematical variations, following a scheme aAbB - bBaA in the second and third moves; the sideline defenses 2...axb1 or 2...Kb2 in the 1...d5 variation are not total stops from the initial threats; in the en-passant moment there's a choice too: 3.cxd6 ep? c5! and Black will not fall in zugzwang; so 3.exd6!! - this effects springs from a natural setting - the Pawn 'c6' is necessary to stop an eventual Qxd5... Pawns 'b6' and 'g4' prevents duals in thematical play, other features are similar to the Author's scheme from "The Kibitzer's Café" July, 29 - see above Page 566.> The last chapter from a Chess-Composition workshop on-line!!"

Konig and Turm: ""Noch im Jahr der Thema(*)-Entdeckung (*the Belén) gelang dem Brasilianer Kornin eine Darstellung mit dem Valladão-Task" Hanspeter Suwe (2007);" (quote taken from here-https://www.chessgames.com/perl/chessuser?uname=vonKrolock)

Tim Krabbe's minuscule mention in #253 in a small edit to the 7/28 P.S: "(NB: see pages 566 [P1380121 ] and 587 of that forum for the on-line development of a Valladao-Belén.)"


http://www.berlinthema.de/Auswahl_PH.pdf-"Das Belén-Thema verlangt den schwarzen Königsmarsch von c1 nach d3 gefolgt von der weißen langen Rochade – wie P.H. richtig anmerkt, sollte man besser von einem „Motiv“ sprechen. Kornins Stück verbindet dieses Motiv vermutlich erstmalig mit einem Valladao.
Auf mich wirkt ein Valladao mit Damenumwandlung allerdings immer „halb“, denn der „eigentliche“ Sonderzug ist doch eine Unterverwandlung? Eine solche würde auch einen selbstverständlichen Schlüssel verhindern."
James Malcom: This is the first Valladao-Belen: the Belen theme plus promotion and en passant. (2020-09-21)
Henrik Juel: Only the cases with Black defending by d7-d5 and Kc1-c2 in his first two moves lead to dual-free full-length variations (2020-09-21)
comment
Keywords: Belen Theme, Valladao Task, En passant, Promotion key, Castling as mating move
Genre: n#
FEN: 8/3p2P1/1Pp5/2P1P3/3B2P1/2p5/p7/RNk1K3
Reprints: H48a Der Reiz des Ungewöhnlichen
König & Turm 22, p. 14, 5/2007
(15) MatPlus.net Forum 8/9/2019
Input: James Malcom, 2020-09-21
Last update: James Malcom, 2020-10-27 more...
58 - P1380128
James Malcom
(34) MatPlus.net Forum 18/9/2019
P1380128
(12+7) C+
#5
1. Sbc3!+ Kc2 2. cxd8=S b5 3. cxb6ep Txe6+ 4. Sxe6 Kd3 5. 0-0-0#
play all play one stop play next play all
http://matplus.net/start.php?px=1600656376&app=forum&act=posts&tid=2343&fid=xshows&page=1

http://www.berlinthema.de/Auswahl_PH.pdf-"Wenn man eine Unterverwandlung haben will, ist die Springerumwandlung in der Regel am einfachsten zu erzeugen, wegen der unterschiedlichen Gangart des Springers. Die (H48b) mag als Erstdarstellung ihre Berechtigung haben, doch daß Schwarz statt b7-b5 auch b7-b6 spielen kann, entwertet m.E. den e.p.-Schlag weitgehend. Zudem wirkt angesichts des ungedeckten Satzschachs das erste Zugpaar künstlich aufgesetzt."
James Malcom: This is the first Valladao-Belen with an underpromotion. However, it is damaged by the common "short" ep and a dualistic move order. (2020-09-21)
comment
Keywords: Belen Theme, Valladao Task, Checking key, under-promotion (S), En passant, Castling as mating move
Genre: n#
FEN: 3b4/1pPPr1p1/4P1P1/p1P5/N1p5/P7/P4P2/RNk1K3
Reprints: H48b Der Reiz des Ungewöhnlichen
Input: James Malcom, 2020-09-21
Last update: Alfred Pfeiffer, 2020-09-22 more...
59 - P1380143
Peter Hoffmann
H48c Der Reiz des Ungewöhnlichen 9/2019
P1380143
(14+9) C+
#5
1. Sxc3+! Kc2 2. b8=T! f5 3. gxf6ep Lb5 4. Txb5 Kd3 5. 0-0-0#
play all play one stop play next play all
See the improved P1380148

http://www.berlinthema.de/Auswahl_PH.pdf-"In der einschlägigen Diskussion im „MatPlus Forum“ schälte sich heraus, daß Darstellungen mit Turm- oder Läuferumwandlung noch nicht existier(t)en, und dies rief P.H. auf den Plan, der ja ausdrücklich unerforschtes Terrain sucht.
In seinem Stück ist die Unterverwandlung in einen Turm im zweiten Zug logisch begründet – was auch hier das erste Zugpaar aufgesetzt wirken läßt. Mir scheint, daß das Belén-Motiv eher eine hinderliche Vorgabe ist ... 51
(Die Zweckreinheit der schwarzen Reihenfolge-Auswahl, welche die Damenumwandlung
widerlegt, soll hier nicht näher untersucht wurden. Unseres Erachtens ist sie zweckrein, falls man bereit ist, den Austausch der Möglichkeit 5. L:e4# durch die Möglichkeit 5. 0-0-0# als bloße Kompensation zu sehen.)"

http://matplus.net/start.php?px=1570441154&app=forum&act=posts&fid=gen&tid=2361&pid=17978#n17978

Post #1-"A wonderfull surprise! PH presented today a brand new Valladao-Belen, its already published in Erik Zierke's online book in PDF on Hoffmann's works:

http://www.berlinthema.de/AUSWAHL_PH.pdf

page 181, with full solution and comments. In page 180 are also presented, and commented, the known examples of Valladao-Belen (Just two so far, one of them evolved online recently here in MP):

http://matplus.net/start.php?px=1569833313&app=forum&act=posts&fid=xshows&tid=2343&pid=17926#n17926

After a promotion to Queen, and a promotion to Knight, now we have a promotion to Rook.

****** Peter, thanks for Your interest in the Valladão-Belén!! :"

Post 7-"In his excellent # 5, Peter Hoffmann introduces important novelties in the VB field: The promotion move act in three different levels of significance (control of b3, of b5 avoiding to affect d3, and - not least- create a threat of mate in two in e4, allowing a consistent en passant part in real play) : 2.b8 = R is the most impressive single movement in the whole VB's history!

He refers to the Belén as a "motif". In the old Rebnora forum discussions Frank Richter alluded to an "ornamental effect". For Erik Zierke, the Belén condition arrive to become an obstacle ('Hindernis') for the more satisfactory expression in the Valladão field (in the same book we find others of Peter Hoffmann's creations in this field)."
James Malcom: The first Valladao-Belen with a rook promotion. (2020-09-22)
more ...
comment
Keywords: Belen Theme, Valladao Task, Capture key, Checking key, under-promotion (T), En passant, Castling as mating move
Genre: n#
FEN: B3b3/1P3pPQ/4p3/3pP1P1/3Pn3/BPp2p2/pP3P2/RNk1K3
Reprints: (1) MatPlus.net Forum 30/9/2019
Input: James Malcom, 2020-09-22
Last update: Alfred Pfeiffer, 2020-09-22 more...
60 - P1380144
James Malcom
Zalmen Kornin

chessproblem.net 10/8/2019
P1380144
(12+9) C+
#5
1. Sc3+! Kc2 2. h8=L! e5 3. fxe6ep cxd4 4. Lxd4 Kd3 5. 0-0-0#
play all play one stop play next play all
https://www.chessproblem.net/viewtopic.php?f=7&t=1078&p=2344&hilit=belen#p2344

"Yes, a Valladao-Belen with a Bishop promotion, and the first to ever appear before the public !"

http://www.berlinthema.de/Auswahl_PH.pdf-"P.H.s (H48c) löste eine verstärkte Suche nach einer Darstellung mit der nun einzig noch feh- lenden Läuferumwandlung aus, und formell ist die (H48e) die Erstdarstellung. Allerdings sehen wir hier dieselbe gravierende thematische Schwäche wie in der (H48b), daß der Doppelschritt vor dem e.p.-Schlag nicht exklusiv ist und Schwarz ebenso den Einzelschritt spielen könnte – wodurch es zum gleichen Spiel kommt nur ohne den thematisch unabdingba- ren e.p.-Schlag."

http://matplus.net/start.php?px=1600576227&app=forum&act=posts&fid=xshown&tid=2367-"****...and the solution now is complete. Yes, You knew already, I'm sure: "habemus episcopus" - after Q, N and R, a promotion to Bishop in a published Valladao-Belen!"
James Malcom: The first Valladao-Belen with a bishop promotion. (2020-09-22)
comment
Keywords: Belen Theme, Valladao Task, Checking key, under-promotion (L), En passant, Castling as mating move
Genre: n#
FEN: 8/4p2P/3p4/pPpp1P2/B1pP1P2/Br3p2/1P3P2/RNk1K3
Reprints: H48e Der Reiz des Ungewöhnlichen
(1) MatPlus.net Forum Moremovers 10/8/2019
Input: James Malcom, 2020-09-22
Last update: Alfred Pfeiffer, 2020-09-22 more...
61 - P1380148
James Malcom
Peter Hoffmann

H48d Der Reiz des Ungewöhnlichen 9/2020
JM nach PH
P1380148
(15+7) C+
#5
1. Sxc3+! Kc2 2. b8=T! d5 3. cxd6ep Dxb5,Dc6 4. Txb5,Lxc6 Kd3 5. 0-0-0#
3. exd6ep? Dxe6+!
3. Lxd5? Dd8!
play all play one stop play next play all
See P1380143

http://www.berlinthema.de/Auswahl_PH.pdf-"James Malcom weist darauf hin, daß ohne die schwarze Logik in der Widerlegung der Damenumwandlung man eine eindeutige Zugreihenfolge in der Lösungsphase erhalten kann. Danke für das Interesse an unserer Schrift!"
James Malcom: Some months back, I managed to improve Hoffmann's P1380143. But has only been published recently alongside it, and ironically in the same month. The point here is that there is but a single solution. It turned out to be scarcely possible, requiring every White man but the queen. (2020-09-22)
comment
Keywords: Belen Theme, Valladao Task, Capture key, Checking key, under-promotion (T), En passant, Castling as mating move
Genre: n#
FEN: B1N1q3/1P1p4/4P1p1/1RP1P1P1/8/BPp2p2/pP3P2/RNk1K3
Input: James Malcom, 2020-09-22
Last update: Olaf Jenkner, 2021-01-04 more...
62 - P1380368
James Malcom
MatPlus.net Forum 22/9/2020
Gewidmet Zalmen Kornin & Peter Hoffmann
P1380368
(14+9) C+
#7
1. Sc3+! Kc2 2. exd4 hxg1=D+,T+ 3. Txg1 Lxh5 4. g4 fxg3ep 5. Txg3 Lg4 6. Txg4 Kd3 7. 0-0-0#
play all play one stop play next play all
http://matplus.net/start.php?px=1601242024&app=forum&act=posts&fid=gen&tid=2488

http://www.berlinthema.de/Auswahl_PH.pdf-"J.M. arbeitete weiter am Valladao-Belén und konnte ihn schließlich gemischtfarbig zeigen! Den „Umwandlungsdual“ halten wir für irrelevant, da ohne Pattmotiv die Turmumwandlung kein eigenständiger Zug ist. Und wir anerkennen durchaus die Pionierleistung! Andererseits ist ein ungedecktes Satzmatt eine sehr häßliche Konstruktionserleichterung."
more ...
comment
Keywords: Belen Theme, Valladao Task, Checking key, En passant, Promotion, under-promotion (t), Castling as mating move
Genre: n#
Computer test: Popeye 4.61
FEN: 8/5B2/6P1/3P3Q/2pq1pb1/Bp2Pp2/pP3PPp/RNk1K1NR
Reprints: H48i Der Reiz des Ungewöhnlichen 9/2020
Input: James Malcom, 2020-09-27
Last update: James Malcom, 2021-12-26 more...
63 - P1380523
Nels H. Nelson
760 Los Angeles Times , p. 30, 28/3/1937
"April Fool Joke"
P1380523
(9+5)
#3
1. gxh6ep+! Kxf7 2. 0-0xg1! Sf6 3. e8=sS#!
play all play one stop play next play all
28/3/1937-https://www.newspapers.com/clip/25408700/chess-by-herman-steiner/

"NELS NELSON

We have heretofore published many of Nelson's fine problems and should like to show any readers the more humorous side of his talent. This winter our distinguished friend is spending his vacation in Los Angles. It is with his kind permission that we are publishing this story and problem.

Nels Nelson, born in Denmark in 1871, emigrated to the United States when 12 years of age. He learned the moves of chess in Denmark and began solving and composing problems in 1894. He was chess editor of the Minneapolis State Chess Asccostion, 1911-1912, president of the Minnesota State Chess Asccostion, 19229-1930, and lives at Hopkins, Minn., a suburb of Minneapolis.

AN APRIL FOOL JOKE

A certain celebrated chess master, who we will designate as Mr. "X," while on in the provinces happened into a tavern which was the mecca of the village chess players. Mr. "X," very fond of practical jokes, conceived a plan of springing on one of the unsuspecting natives. Professing ignorance of the game, the champion of the club offered to teach Mr. "X" its intricacies. After showing Mr. "X' all of the moves with the exception of pawn promotion, pawn takes pawn, etc., and castling, the champion said the following: ""I have purposely omitted three of the maneuvers in chess, which to the beginner are somewhat difficult to grasp. They are pawn promotion-when a pawn reaches the eight rank it ceases to be a pawn but may but it may be converted to any piece on the board and assumes its function at once. It is thus theoretically possible to have as many as nine queens on the board at once, and so on down the line." The champion then went to explain the castling on the king and queen side and emphasized the importance of moving the king first. The act of pawn takes pawn "en passant" was then thoroughly explained and the actual game started with the champion giving odds of queen to Mr. "X," who proved to be a very apt pupil! Mr. "X" lost the first game in short order-walking boldly into a mating net. In the second game he gave the champion quite the battle and won the approbation of that was worthy. In the third game, the champion managed to trap Mr. "X's" queen but had to give up two pieces for it and saw that he had a lost game but continued on in the hope that his experienced opponent would make some mistake. When the game has reached the position in the diagram the champion was dumbfounded to hear Mr. "X" announce mate in three moves. "Impossible!" exclaimed the champion. "You should win, of course, but mate in three cant be done." "Well, if you have interpreted the move and rules correctly, I am certain I see a mate in three," said Mr. "X." "Of course I have interpreted the rules correctly, exclaimed the now irate champion: and I will lay you a wager of dinner for the members of the club that you fail to mate in three moves." "Done!" cried Mr. "X." By this time nearly every member in the club was watching the game with interest. Now, who won this wager? It will be shown in the solution April 11."

11/4/1937-https://www.newspapers.com/clip/25408721/chess-by-herman-steiner/

"SOLUTION TO PROBLEM 760 by N. Nelson: "April Fool Joke."

White: K. on K1 R. on Q7, and KR1: Kt. on KB7 and KB8: B, on QB5: P. on K7, KKt5, and KKt2, Black: K. on KKt2: R. on KKt1: Kt. on K1: B. on KKt8: P. on KR4. (Wh. 9: BL. 5.)

Many members of the club were very fine players and felt their champion would win. Curiously, most of them were pulling for Mr. "X," as the champion was somewhat of a braggard and if he won they felt they would be hearing about it for a long time. They were, therefore, keenly alert when Mr. "X" started to proceed the game. "My first move is pawn takes en passant," said the smiling Mr. "x." "Of course, I anticipated that move," replied the champion, "and I shall meet it with king takes knight." Oh well then I shall make for my second move, castle: taking the bishop," continued Mr. "X." "This move is according to your definition of castling, perfectly legitimate, as the king moves first, and the bishop being on the knight square, certainly is subject to capture." "Well," replied the champion, "I must say your interpretation is far fetched, but I will grant you even this point as I fail to see how you mate on the next move: you evidently overlook the fact that when you promote the pawn the king will be able to capture it. Of course, I am forced to interpose my knight and it is pinned, but the king will still be able to take care of that promoted pawn. " Well," smiled Mr. "X," "I shall, however, mate you by pawn to king eight, discovering check, as I shall claim a black knight for the promoted pawn, which, according to your interpretation of pawn promotion, is perfectly legitimate. You stated I might choose any piece on the board and, of course, as the black knight is the only piece that will mate, I naturally selected it."
Exit champion.

We are publishing the best solution sent in my Ladderite L. A. Post, incidentally only two others solved this April Fool Problem.

Problem 760 to complete the tale that Mr. Nelson started to what I believe to be the logical solution according to the rules given by the local champion.
1. White: Pawn takes pawn "en passant" check.
The local champion then captured the white knight reposing on his "bishop two."
1. Black: king takes knight.
"Now," continued Mr. "X" "I understand to quote you, the king moves firstl in castling."
"That is correct," agreed the champion.
Thereupon Mr. "X" executed the move in the prescribed manner by first moving his king to his king knight square and removing the champion's bishop and then setting his rook down on his king bishop square calling check.
The champion was nonplussed, for in stating the rules for "castling" he had failed to forsee a circumstance of this kind. He was forced to admit that, according to his own statement, such a move was possible But seeing in spite of this that it was still impossible to checkmate on the next move, he conceded the point and interposed his knight.
2. Black: Knight to king bishop three.
"Did you not say," resumed Mr. "X," "that in 'pawn promotion' you could reclaim to any piece on the board?"
"That is correct," conceded the champion, "but since you insist on taking me literally I might add that there is no "queen' on the board you may claim in one."
"In that case," stated Mr. "X," "I will be equally generous and present you with a 'knight.'"Whereupon Mr. "X" removed the pawn at king seven and placed a black 'knight' at king eight discovering checkmate to the champion's "king."
"Such a thing is impossible !" cried the outraged champion.
"Not at all," replied Mr. "X," "for according to your statement that "upon reaching the eight rank a pawn be converted to any piece on the board and assumes its function at once.'"
To this the other members agreed. So the champion held a dinner in honor of Mr. "X," the most apt pupil he had ever taught.

Respectfully yours,

L.A. Post
Seaman, First Class, U.S. Navy,
U.S..S Texas, San Pedro, Cal."
Henrik Juel: Some help is needed here, James
At least for me (2020-10-01)
A.Buchanan: Hi Henrik I am guessing it’s a cheatyface Valladao:
1. gxh6ep+ Kxf7 2. 0-0+ Sf6 3. f8=sS#
No proof for the ep, castling with capture and promotion to black officer (2020-10-02)
James Malcom: Bingo Andrew! (2020-10-02)
Henrik Juel: Even though I ought to stand by my fellow danish author:
This is a most crude 'joke' problem, especially the 'castling' with capture (2020-10-02)
A.Buchanan: It's kind of a running gag: three silly jokettes which do combine relatively harmoniously (2020-10-02)
A.Buchanan: 1. ... Kf6 allows a short mate, robbing White of the Valladao. 4nNbn/3RP1kN/8/6Pp/8/8/8/4K1bR is the best I can find, fixing the problem, and with less material (2020-10-02)
A.Buchanan: I was hoping that someone would spot that I have shifted a unit to h7 - i.e. the e.p. is even more Foolish :-) I claim it "improves" the problem because currently the e.p. *might* be legal :-) If this is too crude for some, then 4nNr1/3RP1k1/6N1/4P1Pp/8/8/8/4K1bR works. Note you need sTg8 to prevent 2. Sh8#, but wSg6 is blocking g-file, so wBg2 is still free to find other duties on e5. (2020-10-03)
James Malcom: Excellent improvements, Andrew! (2020-10-06)
A.Buchanan: Thanks James: do you think the one with Sh7 is excessively silly? (2020-10-06)
James Malcom: Yes, 'd say a bit too silly. (2020-10-16)
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comment
Keywords: Joke, Valladao Task, Joke promotion (s), En passant as key, Castling, Checking key, under-promotion (s)
Genre: 3#
FEN: 4nNr1/3RPNk1/8/2B3Pp/8/8/6P1/4K1bR
Reprints: Los Angeles Times , p. 13, 11/4/1937
Input: James Malcom, 2020-10-01
Last update: James Malcom, 2021-02-23 more...
64 - P1380892
Courtnay Lemon
343 American Chess Magazine Volume 2, p. 284, 12/1898
P1380892
(7+6)
#3
1. bxc6ep+! Kc7 2. 0-0-0 Dxb4 3. a8=S#
play all play one stop play next play all
Solution text from the 2/1899 issue: "A clever rendering of this "triple idea." It will be seen that Black cannot play simply 2.R-Q sq on account of 3. Q x Q ch."
zum Autor heißt es im 'ACM': Courtenay Lemon, New York
James Malcom: I found this most excellent early Valladao while ago, but only today did I finally find it again. This is the second one that I've found, i.e. P1380523

Is this the second oldest known Valladao after the 1867 P1360420 found by Keym?

The mainline should be C+, with the "legitimate" ep key, but with many dualed sidelines. (2020-10-14)
Henrik Juel: Something seems missing, James
There is no mate 3... Kc8,Kxc6 (2020-10-14)
Henrik Juel: Adding wSe7 would help (2020-10-14)
James Malcom: Henrik, Mario-many thanks!-has now fixed the position. I had missed the wSe7 when entering! (2020-10-14)
comment
Keywords: Joke (e.p.), En passant as key, Castling, under-promotion in mating move (S), Valladao Task
Genre: 3#
FEN: 1b6/Pk2N3/1q6/1Pp5/1Q6/4p1p1/2P5/R3K3
Input: James Malcom, 2020-10-14
Last update: Mario Richter, 2020-10-14 more...
65 - P1381642
Milomir Babic
8650 Phénix 301-302 11-12/2019
P1381642
(8+7)
s#11
1. d3-d4+! f7-f5 2. g5xf6ep+ Tg4-g6 3. 0-0+ Lf4-c1 4. Kg1-h1 h5-h4 5. Lg3-h2 h4-h3 6. f6-f7 b5-b4 7. f7-f8=L h6-h5 8. Lf8-d6 h5-h4 9. Lh2-g1 h3-h2 10. Ld6xh2 h4-h3 11. Tf2-g2 h3xg2#
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SCHRECKE: Nach 4. ... b4 geht 5.Lh2 oder 5.f7 (2020-11-09)
comment
Keywords: Checking key, En passant, Castling, under-promotion (L), Valladao Task, Pawn mate
Genre: s#
FEN: 8/5p1B/7p/1p4Pp/5br1/1N1P2B1/5R2/1k2K2R
Input: Marcin Banaszek, 2020-11-09
Last update: Alfred Pfeiffer, 2020-11-09 more...
66 - P1381790
James Malcom
Facebook 24/09/2020
P1381790
(7+5) C+
#3
1. h8=D+! e5 2. dxe6ep+ Kxd3 3. 0-0-0#
2. ... Kxb4 3. Db2#
play all play one stop play next play all
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comment
Keywords: Valladao Task, Promotion key (D), En passant, Castling as mating move, Checking key, Flight-giving key
Genre: 3#
Computer test: popeye 4.85
FEN: 8/4p2P/3p4/2pP4/1R6/2kBp3/8/R3K1N1
Input: James Malcom, 2020-11-12
Last update: Alfred Pfeiffer, 2020-11-13 more...
67 - P1383322
Werner Keym
7 Die Schwalbe 215, p. 241, 10/2005
Hanspeter Suwe gewidmet
P1383322
(5+4) C+
#3
1. Th5! droht 2. Th8#
1. ... g5+ 2. f5xg6ep 0-0-0 3. a8=D#
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comment
Keywords: Valladao Task, En passant, Castling, Promotion
Genre: 3#
Computer test: popeye 4.85
FEN: r3k3/PR4p1/8/5PR1/7K/8/6p1/8
Input: Alfred Pfeiffer, 2020-12-24
Last update: Alfred Pfeiffer, 2020-12-24 more...
68 - P1385600
Michel Caillaud
MatPlus.net Forum 14/01/2021
P1385600
(14+14)
PG in 12.5
Staugaard castling
b) 1. e4 h5 2. e5 h4 3. Dh5 h3 4. Le2 hxg2 5. h4 Th6 6. Th3 Tb6 7. Ta3 d6 8. Ta6 Kd7 9. Lg4+ f5 10. exf6ep+ Kc6 11. fxe7 bxa6 12. e8=T Kb7 13. 0-0-0-0-0-0
play all play one stop play next play all
Objective: Staugaard (Pam-Krabbé) Valladao.
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comment
Keywords: Unique Proof Game, Staugaard castling, Valladao Task, En passant, Castling, Prenix (T), Promotion (t)
Genre: Retro, Fairies
FEN: rnbq1bn1/pkp3p1/pr1p4/7Q/6BP/4K3/PPPPRPp1/RNB3N1
Input: A.Buchanan, 2021-01-21
Last update: Rainer Staudte, 2021-05-10 more...
69 - P1390560
Geir Sune Tallaksen Østmoe
Discord Chess Problems & Studies Server 02/05/2021
4. Platz
Discord Composition Tourney 1
P1390560
(14+5)
#1
b) wKf5->e1
c) wKf5->g1
a) 1. dxe6ep#
b) 1. 0-0#
c) 1. f8=D,T#
play all play one stop play next play all
Henrik Juel: Black captured [Lc1] and b7xDa6, so in part a) last move was e7-e5
1.dxe6ep#, 1.0-0#, 1.f8=DT# (2021-06-08)
comment
Keywords: Valladao Task, Castling as mating move, En passant, Tolerated dual promotion, under-promotion (T)
Genre: Retro
FEN: B7/p4P2/p7/P2PpK2/6P1/3P1kpP/1P1P2R1/2NN3R
Input: A.Buchanan, 2021-06-08
Last update: Alfred Pfeiffer, 2021-09-30 more...
70 - P1391291
Pascal Wassong
Messigny 1998
4. Preis
P1391291
(14+14) C+
BP in 13.5
1. a4 d5 2. Ta3 Lg4 3. Te3 Lf3 4. exf3 Kd7 5. Lb5 Kd6 6. Se2 d4 7. 0-0 d3 8. Kh1 dxe2 9. d4 exf1=L 10. d5 Ld3 11. Te2 Lf5 12. Dd3 Lc8 13. Lf4+ e5 14. dxe6ep+
play all play one stop play next play all
A.Buchanan: 14. ... Kc5! would move beyond the diagram check. (2021-07-31)
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (l), Pronkin Theme (l)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 12.5
FEN: rnbq1bnr/ppp2ppp/3kP3/1B6/P4B2/3Q1P2/1PP1RPPP/1N5K
Reprints: Problemesis 4 08/1998
M4 Phénix 66, p. 4112, 09/1998
13 Orbit 30, p. 318, 04/2006
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
71 - P1391292
Viktor Peretyatko
R307 The Problemist , p. 28, 01/2001
P1391292
(14+9) C+
BP in 12.5
1. e4 d5 2. exd5 Sc6 3. dxc6 Ld7 4. cxb7 Lb5 5. b8=S Dd7 6. Sxd7 0-0-0 7. Sxf8 Txd2 8. Sxh7 Txh7 9. g4 Th5 10. Lh3 Te2 11. Kf1 Tc5 12. g5+ f5 13. gxf6ep+
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (S), Ceriani-Frolkin Theme (S), Prentos Theme (S)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 11.5
FEN: 2k3n1/p1p1p1p1/5P2/1br5/8/7B/PPP1rP1P/RNBQ1KNR
Reprints: 9 Orbit 30, p. 317, 04/2006
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
72 - P1391293
Ayako Okaya
R003 Problem Paradise 13 03/1999
P1391293
(11+15) C+
BP in 11.0
1. d3 e6 2. Lh6 Dh4 3. Dd2 g5 4. Dc3 Lxh6 5. Dxh8 Kf8 6. Dg7+ Kxg7 7. Sa3 Kh8 8. 0-0-0 g4 9. f4 gxf3ep 10. Td2 fxe2 11. g4 exf1=T#
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (t), Phoenix (t)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 10.0
FEN: rnb3nk/pppp1p1p/4p2b/8/6Pq/N2P4/PPPR3P/2K2rNR
Reprints: 3 Orbit 30, p. 216, 04/2006
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
73 - P1391294
Per Grevlund
251 Problemskak 6 04-06/2009
to L.Larsen for his 90 years
6. Lob
Problemskak 2008-10
P1391294
(11+13) C+
BP in 11.0
1. g4 b5 2. g5 b4 3. g6 b3 4. gxh7 bxa2 5. hxg8=S axb1=S 6. Sh6 Sxd2 7. Kxd2 g5 8. Ke3 Lxh6 9. Ld2 0-0 10. Dc1 g4 11. f4 gxf3ep+
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling (sk), En passant (s), under-promotion (Ss), Ceriani-Frolkin Theme (Ss), Prentos Theme (Ss), Phoenix (s), Prenix (S)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 10.0
FEN: rnbq1rk1/p1pppp2/7b/8/8/4Kp2/1PPBP2P/R1Q2BNR
Reprints: Problemskak 21 2013
Input: A.Buchanan, 2021-07-03
Last update: Björn Enemark, 2022-08-07 more...
74 - P1391295
Andreas Thoma
17289 Die Schwalbe 288 12/2017
P1391295
(13+12) C+
BP in 13.5
1. b4 g5 2. b5 g4 3. b6 g3 4. bxa7 gxh2 5. axb8=S hxg1=S 6. Sxd7 Sxe2 7. Sc5 Sc3 8. Se4 Kd7 9. Dh5 Ke6 10. g4 Ld7 11. Lh3 Le8 12. 0-0 Dd7 13. g5+ f5 14. gxf6ep#
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling (wk), En passant, under-promotion (Ss), Phoenix (s), Prenix (S)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 12.5
FEN: r3bbnr/1ppqp2p/4kP2/7Q/4N3/2n4B/P1PP1P2/RNB2RK1
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
75 - P1391296
Jonathan Mestel
WCCC Ohrid 09/2018
2. ehrende Erwähnung
Champagne Tourney, 2018
P1391296
(15+13) C+
BP in 13.5
1. c4 h5 2. Db3 h4 3. Kd1 h3 4. Kc2 hxg2 5. Sh3 g1=S 6. Lg2 Sf6 7. Lc6 Sf3 8. Tg1 Se4 9. Txg7 f6 10. Tg1 Lg7 11. exf3 0-0 12. c5+ d5 13. cxd6ep+ Tf7 14. d7
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling (sk), En passant, under-promotion (s), Ceriani-Frolkin Theme (s)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 13.0 or 12.5
FEN: rnbq2k1/pppPprb1/2B2p2/8/4n3/1Q3P1N/PPKP1P1P/RNB3R1
Input: A.Buchanan, 2021-07-03
Last update: Marcin Banaszek, 2023-09-29 more...
76 - P1391297
Marek Kolcak
WCCC Ohrid 09/2018
1. ehrende Erwähnung
Champagne Tourney, 2018
P1391297
(12+15) C+
BP in 12.5
1. f4 c5 2. f5 Da5 3. f6 Kd8 4. fxe7 Kc7 5. e8=T b6 6. Te3 La6 7. Th3 Lxe2 8. Sf3 Lxd1 9. Le2 c4 10. 0-0 Lc5+ 11. d4 cxd3ep+ 12. Tf2 Lxf2+ 13. Kf1
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (T), Prenix (T)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 12.0 or 11.5
FEN: rn4nr/p1kp1ppp/1p6/q7/8/3p1N1R/PPP1BbPP/RNBb1K2
Input: A.Buchanan, 2021-07-03
Last update: Marcin Banaszek, 2023-09-29 more...
77 - P1391298
Ladislav Packa
Emil Klemanic
Michal Dragoun
Ladislav Salai

WCCC Ohrid 09/2018
2. Lob
Champagne Tourney, 2018
P1391298
(15+12) C+
BP in 11.5
1. h4 e6 2. h5 Dh4 3. c3 Dc4 4. f4 Lb4 5. f5 Se7 6. f6 0-0 7. fxe7 Sc6 8. exf8=S Se7 9. Sxh7 Kxh7 10. Dc2 Kh6 11. d4 g5 12. hxg6ep+
play all play one stop play next play all
Henrik Juel: Thanks for posting this nice set of Valladao proof games, Andrew (2021-07-03)
A.Buchanan: Welcome Henrik - it's a popular and accessible theme :) (2021-07-03)
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (S), Ceriani-Frolkin Theme (S), Prentos Theme (S)
Genre: Retro
Computer test: C+ Euclide 1.01, no solution in 10.5
FEN: r1b5/ppppnp2/4p1Pk/8/1bqP4/2P5/PPQ1P1P1/RNB1KBNR
Input: A.Buchanan, 2021-07-03
Last update: Marcin Banaszek, 2023-09-29 more...
78 - P1391300
Igor Vereshchagin
Michel Caillaud

IV Phénix 206, p. 8574, 06/2011
P1391300
(15+12) C+
BP in 15.5
1. e2-e4 c7-c5 2. Lf1-d3 c5-c4 3. Sg1-e2 c4-c3 4. 0-0 c3xd2 5. c2-c4 e7-e6 6. Se2-c3 Lf8-a3 7. Dd1-e2 d2-d1=S 8. f2-f4 Sd1-f2 9. b2xa3 Sf2-h3 10. g2xh3 Ke8-e7 11. Tf1-f2 Ke7-f6 12. Kg1-f1 Kf6-g6 13. e4-e5 f7-f5 14. e5xf6ep Kg6-h6 15. f4-f5 g7-g5 16. f5xg6ep#
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant (2), under-promotion (s), Ceriani-Frolkin Theme (s)
Genre: Retro
Computer test: Euclide 1.01, no solution in 14.5
FEN: rnbq2nr/pp1p3p/4pPPk/8/2P5/P1NB3P/P3QR1P/RNB2K2
Reprints: 791 Problemskak 17, p. 9, 2012
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
79 - P1391301
Brian E. Chamberlain
R450 The Problemist 09/2012
dedicated to J.Ling
P1391301
(12+14) C+
BP in 16.0
1. Sb1-c3 Sg8-f6 2. Sc3-d5 Sf6-e4 3. Sd5xe7 Se4xd2 4. Ke1xd2 a7-a5 5. Kd2-c3 a5-a4 6. Kc3-b4 Sb8-a6 7. Kb4-a5 Lf8xe7 8. e2-e4 0-0 9. Dd1-h5 f7-f5 10. Lf1-e2 f5-f4 11. Le2-g4 f4-f3 12. Sg1-e2 f3xe2 13. Th1-d1 Tf8-f3 14. Td1-d5 Tf3-a3 15. Td5-b5 e2-e1=L+ 16. b2-b4 a4xb3ep#
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (l), Non-standard material (l)
Genre: Retro
Computer test: Euclide 1.01, no solution in 15.0
FEN: r1bq2k1/1pppb1pp/n7/KR5Q/4P1B1/rp6/P1P2PPP/R1B1b3
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
80 - P1391302
Unto Heinonen
Tehtäväniekka 10/2014
Lob
Jubile E Saazenheimo-95
P1391302
(14+12) C+
BP in 17.5
1. d2-d4 g7-g6 2. d4-d5 Lf8-h6 3. d5-d6 Ke8-f8 4. d6xe7 Kf8-g7 5. Dd1-d6 c7-c5 6. Dd6xb8 b7-b5
7. Db8-b6 a7xb6 8. e7-e8=D Ta8-a4 9. De8-e7 Ta4-h4 10. e2-e4 d7-d5 11. Lf1-d3 Lc8-g4 12. Sg1-e2 Lg4-h5 13. 0-0 Lh6-d2 14. g2-g4 Ld2-a5 15. g4xh5 g6xh5 16. Lc1-f4 Kg7-g6 17. e4-e5 f7-f5 18. e5xf6ep#
play all play one stop play next play all
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Keywords: Unique Proof Game, Valladao Task, Castling, En passant, Promotion (D), Phoenix (D)
Genre: Retro
Computer test: Euclide 1.01, no solution in 16.5
FEN: 3q2nr/4Q2p/1p3Pk1/bppp3p/5B1r/3B4/PPP1NP1P/RN3RK1
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
81 - P1391303
Hitoshi Yanami
R253 Problem Paradise 84 10/2018
P1391303
(12+16) C+
BP in 18.0
1. g2-g3 h7-h5 2. Lf1-g2 h5-h4 3. Lg2-c6 d7xc6 4. d2-d4 Lc8-e6 5. Dd1-d3 Dd8-d7 6. Dd3-b5 c6xb5 7. Lc1-f4 Sb8-c6 8. Ke1-d2 0-0-0 9. Kd2-e3 Dd7-e8 10. Sb1-d2 Td8-d5 11. Ta1-f1 Td5-h5 12. d4-d5 Kc8-b8 13. d5-d6 Le6-d5 14. d6-d7 e7-e5 15. d7-d8=L e5-e4 16. Ld8-f6 g7xf6 17. Lf4-d6 Lf8-h6 18. f2-f4 e4xf3ep+
play all play one stop play next play all
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, Promotion (L), Ceriani-Frolkin Theme (L)
Genre: Retro
Computer test: Euclide 1.01, no solution in 17.0
FEN: 1k2q1nr/ppp2p2/2nB1p1b/1p1b3r/7p/4KpP1/PPPNP2P/5RNR
Input: A.Buchanan, 2021-07-03
Last update: Alfred Pfeiffer, 2021-11-26 more...
82 - P1391304
Ivan Denkovski
76 feenschach 183, p. 382, 08/2010
Lob
P1391304
(13+13) C+
BP in 24.0
1. h2-h4 a7-a5 2. h4-h5 Ta8-a6 3. h5-h6 Ta6-e6 4. h6xg7 Te6-e3 5. f2xe3 h7-h5 6. Ke1-f2 Sg8-h6 7. g7-g8=L Lf8-g7 8. Kf2-g3 Lg7-e5 9. Kg3-h3 f7-f6 10. Lg8-b3 h5-h4 11. c2-c4 0-0 12. Sb1-a3 Dd8-e8 13. Sa3-c2 De8-h5 14. c4-c5 Sh6-f7 15. c5-c6 Sb8-a6 16. c6xb7 c7-c5 17. a2-a3 c5-c4 18. Ta1-a2 c4-c3 19. Sc2-a1 c3-c2 20. b7-b8=D c2xd1=T 21. Db8-c7 Td1xf1 22. Dc7-c2 Tf1-f2 23. Dc2-d1 d7-d5 24. g2-g4 h4xg3ep#
play all play one stop play next play all
Henrik Juel: Euclide 1.01 found the solution quickly, but later got stuck on pos. 112, and I killed the program after some 20 hours (2021-07-04)
A.Buchanan: Congratulations Henrik you have invented the concept of "HC++" (2021-07-04)
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comment
Keywords: Unique Proof Game, Valladao Task, Castling, En passant, under-promotion (Lt), Promotion (D), Pronkin Theme (D), Phoenix (t), Prenix (LD)
Genre: Retro
Computer test: Stelvio 1.5, in 2sec.
FEN: 2b2rk1/4pn2/n4p2/p2pb2q/8/PB2P1pK/RP1PPr2/N1BQ2NR
Reprints: feenschach 212 04/2015
Input: A.Buchanan, 2021-07-03
Last update: Reto, 2023-08-19 more...
83 - P1391341
Gianni Donati
v Best Problems 50 04/2009
2nd Honourable Mention,
E. Minerva 45 JT
P1391341
(13+14) C+
BP in 22.0
1. h4 a5 2. Th3 a4 3. Tb3 axb3 4. Sc3 bxa2 5. b3 d5 6. La3 Lf5 7. Db1 e6 8. Kd1 Dg5 9. hxg5 c5 10. g6 Sc6 11. gxh7 g5 12. Kc1 Lg6 13. Kb2 f5 14. Dd1 Sf6 15. Sb1 Tg8 16. h8=T 0-0-0 17. Th1 Lh6 18. Kc3 Tg7 19. Kd3 c4 20. Ke3 c3 21. Lc1 g4+ 22. f4 gxf3ep+
play all play one stop play next play all
HJ: last moves were something like 21... g5-g4+ 22.f2-f4 gxf3ep+
so it suffices to test the position with Pf3 on g5 and a wP added on f2
C++ means C+ plus that no shorter solution can be found.
A.Buchanan: The definition of Pronkin seems over-narrow, in two ways:
(1) The original officer must be captured: why? Standardization of material can be achieved by later Ceriani-Frolkin of the promoted officer, or (if S or T) by capture of another officer. In *any* of these three cases, it's an achievement for the promoted unit to have doing a homecoming.
(2) And this capture must happen *before* the homecoming of promoted officer: again why? This is a similar timing irrelevancy to "Phoenix", where the proper concept is "Nix".
So there are all these other fine scenarios which are completely nameless. Not to moan: how to fix all this? (2021-07-04)
A.Buchanan: @Henrik, I like your concept of "C++" (the well-known programming language). For positions with checks in the final diagram clearly testing n & n-1.0 suffices. Where there is no check in the final diagram, then the testing should be n, n-0.5, n-1.0 & n-1.5. Even though this is a bit of a bore, in most cases the other cases are very quick. This is the minimum set of tests necessary to *guarantee* no shorter PGs exist. To me, it seems worth pushing that extra yard, because otherwise C++ will be tarred with the same subjective incompleteness as C+. (2021-07-04)
comment
Keywords: Unique Proof Game, Valladao Task, Castling (sg), Promotion (T), Phoenix (T), Pronkin Theme (T), Impostor (Th1)
Genre: Retro
Computer test: C++ Euclide 1.01
FEN: 2kr4/1p4r1/2n1pnbb/3p1p2/8/1Pp1Kp2/p1PPP1P1/RNBQ1BNR
Input: A.Buchanan, 2021-07-04
Last update: A.Buchanan, 2021-07-04 more...
84 - P1399595
David Dana-Bashian
Chess Life and Review 4/1990
P1399595
(6+16)
h#3
1. ... fxg6ep 2. 0-0 c8=S 3. Dh8 Sxe7#
play all play one stop play next play all
http://uscf1-nyc1.aodhosting.com/CL-AND-CR-ALL/CL-ALL/1990/1990_04.pdf
Henrik Juel: White captured nothing, so Black captured a7xb6xc5xd4xc3, cxd, d7xc6 hxg, and did two more pawn captures to explain the pawn inversion on the f-line; as [Lf1] was captured at home, all 10 missing white men are accounted for
White has no possible last move, so he has the move, and the stipulation is really h#2.5
Last move was g7-g5, because this is the only way to give White a previous move (Kg5-h5), so White may start with an ep capture (2022-03-02)
Henrik Juel: HC+ Popeye 4.61 with analysis (2022-03-02)
comment
Keywords: Valladao Task
Genre: h#
FEN: 4k2r/1pPbn3/2p2q1P/3p1PpK/3bprpn/4pp2/4P1P1/8
Input: James Malcom, 2022-03-02
Last update: James Malcom, 2022-03-02 more...
85 - P1400824
Otto Kerekes
Tivadar Kardos
Andrew Buchanan

France-Echecs 23/04/2022
OK & TK, correction AB
P1400824
(11+15)
h#2
b) wBg2 -> sB
a) 1. cxd4 Lxc4 2. Dd5 Ld3#
not 1. cxd3ep? Txd1 2. dxc2 Lxc2# because last move was 0-0.
b) 1. cxd3ep cxd3+ 2. Kf3 Lxd1# because last move was d2-d4.
play all play one stop play next play all
Corrects P0005275
Henrik Juel: C+ Popeye 4.61 and analysis (2022-04-23)
Henrik Juel: solutions
a) 1.cxd4 Lxc4 2.Dd5 Lxc2#
not 1.cxd3ep? Txd1 2.dxc2 Lxc2, because last move could be 0-0
b) 1.cxd3ep cxd3+ 2.Kf3 Lxd1# (2022-04-23)
Mario Richter: In a), why not 1. cxd3ep?
Andrew: "because last move was 0-0."
Henrik: "because last move could be 0-0"
Mario: "because d2-d4 definitively was not White's last move" (2022-04-24)
Henrik Juel: You are right, Mario
But my argument suffices to rule out the ep capture, which is allowed only if you can show that last move was d2-d4 (2022-04-24)
A.Buchanan: Thanks Mario. I think that our opinions are consistent. I wanted to emphasise the castling because of Valladao. In b), h8=L is accurate, even if we never know the result of e8=X in either twin. (2022-04-25)
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Keywords: Valladao Task, En passant as key, Castling in the retro play, Promotion (L), Castling (wk)
Genre: h#, Retro
Computer test: HC+ Popeye v4.61 & Retractor 2 which determines that only candidate last move are a) d2-d4 & 0-0 b) d2–d4. Manual logic determines in a) that last move was not in fact d2-d4 because wPe would promote on wrong colour square. Also C+ with rawbats
FEN: 8/p1p5/1B6/q1p1b3/r1pPkpp1/1Bp3Pb/PPP2PPr/1n1n1RK1
Input: A.Buchanan, 2022-04-23
Last update: A.Buchanan, 2023-08-15 more...
86 - P1401480
Jean-Michel Trillon
v Rex Multiplex 2 04/1982
to C.Caminade
2nd Honourable Mention
P1401480
(6+8) cooked
#4 AP
Maximummer
b) g6->g5
a) 1. Ld6! Td8 2. fxg6 Txd5 3. g7 Th5 4. g8=D#
b) 1. fxg6ep Txd5 2. Le5 0-0-0 3. g7 Th8 4. gxh8=D/T#
play all play one stop play next play all
a) Black had a candidate last move b7-b5 of length 2. The only way this might not have been played is if bK was in check from e8 namely Kd8xDTe8,Kf7xDe8. So certainly Black castling rights are lost. With this known, there is still a unique solution.
b) Again, b7-b5 looms, and this time if Black castling rights are lost, there is no solution. The only possible way we can operate is if the last move was g7-g5. But we are only permitted to play this if we can show that the last move *was* not one of Kd8xDTe8,Kf7xDe8. I.e. under AP we need to castle after the fact. There is a unique solution after the ep, which does indeed include castling.
Cook: b) R: 1. Th4xDh5,Th4xLh5,Th6xDh5,Th6xLh5
Henrik Juel: a) C+ Popeye 4.61
1.fxg6 Txd5 2.Le5 0-0-0 3.g7 Th8 4.gxh8=DT#
b) no solution (2022-05-27)
Henrik Juel: I shall leave the analysis to you, Andrew... (2022-05-27)
A.Buchanan: OK, Henrik: please check my suggested solutions & rationale :) I find this a beautiful problem (2022-05-28)
A.Buchanan: In (b), is it possible that Black has just played RxQBh5? If this is feasible, it would apply even if Black 00 rights are still on. Cook? (2022-05-28)
Mario Richter: Looks indeed like a cook.

One can manually retract e.g. R: Th4xLh5 and use popeye to check if in the resulting position the reverse of this retraction is legal:
begin
remark Position after R: Th4xLh5
pieces white Bb8 Pd5 Pf5 Bh5 Ph3 Pd2 Ka1
black Ra8 Ke8 Pb7 Pd7 Ph7 Pa6 Pg5 Rh4
cond Maximummer
option HalfDuplex
stip h~0.5
end

This gives:
1...Rh4*h5
1...Ke8-e7
1...Ke8-d8
1...Ke8-f8

solution finished. Time = 0.013 s (2022-05-29)
A.Buchanan: Thanks Mario. I showed this problem on the international zoom call last night, and Siegfried spotted the cook immediately. Can g4 and h4/h6 be plugged suitably with pawns? Can't just shift bPh6 to h5, because it means that in a), bPg6 might have just captured checking Q/B, while not disrupting Black 000 rights. But I think can shift wPh3 to h4, together with adding Pg4 (Black or White - I prefer White aesthetically). Does this work? (2022-05-29)
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comment
Keywords: a posteriori (AP) (Type Petrovic), Maximummer, Castling (sg), En passant as key, Promotion (D), Valladao Task, Superseded by (P1401566)
Genre: n#, Retro, Fairies
Computer test: Popeye v4.87 & not-so-simple retro-logic to identify the cook
FEN: rB2k3/1p1p3p/p5p1/3P1P1r/8/7P/3P4/K7
Input: A.Buchanan, 2022-05-27
Last update: A.Buchanan, 2022-06-02 more...
87 - P1401495
Igor Vereshchagin
Odessa 1997
Special commendation
P1401495
(10+14) C+
h#2 (AP)
1. a4xb3ep+ Sxa5+ 2. Kd5 0-0-0# (by AP not Td1#?)
R: 1. b2-b4 Kb4-c4+ 2. Sd6-b7,Sd6xLc7
play all play one stop play next play all
With the typo wPd5 corrected to e5, the two forward candidate solutions are correct. How about the retro? Assume that White castling rights remain. bBg5 is promoted, and did so on c1 or g1. In either case, there were 6 pawn caps by Black, but in the former case, the blockaded wRh was not consumable. So the promotion must have been on g8, and White can't retract h2-h3. The missing White unit is light B, so was not just captured on e5 or b4. wRf6 is promoted, say wPd, which would have involved no captures.

This leaves b2-b4, preceded by Kb4-c4+ and before that Sd6-b7. Prior to b2-b4, why couldn't bQ have just played e.g. Qa8-a5+ instead? Because there would still be no prior move: wSb7 can't have just come from h5 or e6. Similarly Rc3-a3 has no precedent.

We don't know exactly what happened to sLc, but that doesn’t affect the soundness. It might have enabled wPc or wPd to capture. wPd did promote, but maybe it was wPc that after capturing promoted to T. Alternatively, Sd6xLc7 was possible.
Henrik Juel: Popeye 4.61 with 'opt enp b3' found no solution (2022-05-27)
Gerald Ettl: Schaut so aus, als ob die sDa5 nach e5 muss. 1.axb3 ep Sa5+ 2.Kxd5 0-0-0# (2022-05-27)
Gerald Ettl: aber auch 2.-Td1# ? (2022-05-27)
Henrik Juel: Andrew, can you throw any light on this problem? (2022-05-28)
Henrik Juel: Gerald, in AP problems like this one White must castle to legitimize the ep capture key (2022-05-28)
A.Buchanan: Hi Henrik, Gerald. I found this one in WinChloe with the current diagram. It gave the "solution" 1. axb3ep+ Sxa5+ 2. Kd5?? 0-0-0#. However when I tried running the WinChloe solver just now, it said there's no solution. Quite right: Rf5 controls d5. I don't think we can shift Qa5 to e5 though.
My first thought is that wPd5 should be on e5. Check my suggested solution in the solution text. However, as you will see, I think we need a second thought as well! Hope the finest retro minds can figure this out. Failing that, we could ask Igor. (2022-05-28)
Mario Richter: The diagram in the reprint in 'Uralsky Problemist' is exactly as given here. The solution given there without further explanation is: 1. ab+ (e.p.) Sxa5+ 2. Kd5 0-0-0#!
Notice that the second black move doesn't contain a capture sign!

Some typos in Andrew's analysis:
The black potential promotion squares should be c1 and g1.
White's last move couldn't have been b3-b4?? simply because that would give an illegal check. (2022-05-28)
A.Buchanan: Thanks Mario for the careful reading. I’ve fixed the errors. Pd5 may be a typo in the reprint then. It also creates a bogus retraction d4-d5, so I don’t think it can be right. Now for Igor. (2022-05-29)
A.Buchanan: Joaquim Crusats spotted R: 1. b2-b4 Kb4-c4+ 2. Sd6-b7, which I'm sure is the intended retraction. So we diagnose a single typo that occurred in the Uralsky reprint diagram: wPe5 appeared on d5. I suggest correcting it here. (2022-05-30)
A.Buchanan: Author confirmed this was a typo (2022-11-23)
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comment
Keywords: a posteriori (AP) (Type Petrovic), En passant as key, Castling (wg), Promotion (Tl), Valladao Task
Genre: h#, Retro
Computer test: Once the diagram typo was fixed, C+ Popeye v4.87 & basic but tricky retro logic
FEN: 3n4/1Np1p1p1/4pn2/q1p1PRb1/pPk1pr2/r6P/P4PP1/R3K3
Reprints: 18 The Ural's Problemist 13, p. 5, 02/1998
Input: A.Buchanan, 2022-05-27
Last update: A.Buchanan, 2022-05-30 more...
88 - P1401497
Mario Velucchi
Scacco! 1998
P1401497
(5+5) C+
h#2.5 (AP)
1. ... cxb6ep
Not 2. Ta7? bxa7 3. Kd8 axb8=D#
But 2. Sxa6! Ld6 3. 0-0-0 b7# AP
play all play one stop play next play all
Under AP Type Petrovic, the ep is enabled by the later castling
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comment
Keywords: a posteriori (AP) (Type Petrovic), Valladao Task, Castling (sg), En passant as key, Promotion (D)
Genre: h#, Retro
Computer test: HC+ Popeye v4.87 & simple retro-logic
FEN: rn2kB2/3p4/P1P5/KpP5/8/8/8/8
Input: A.Buchanan, 2022-05-27
Last update: A.Buchanan, 2022-05-28 more...
89 - P1401566
Jean-Michel Trillon
Siegfried Hornecker
Andrew Buchanan

Discord Chess Problems & Studies Server 02/06/2022
J-MT, correction SH & AB
P1401566
(7+8) C+
#4 AP
Maximummer
b) g6->g5
a) 1. Ld6 Td8 2. fxg6 Txd5 3. g7 Th5 4. g8=D#
b) 1. fxg6ep Txd5 2. Le5 0-0-0 3. g7 Th8 4. gxh8=D,T#
play all play one stop play next play all
What did Black play last, and why not b7-b5?
a) Can only be Kxe8 to escape check. Thus castling rights are definitely lost.
b) Also the possibility of g7-g5, so 000 rights can remain. This breaks the earlier solution but allows another solution in which AP retro-justifies ep with 000, which is also necessary for the mate. The solution beginning 1.Ld6 does not work any more, because under RS convention, castling is legal and so must be played.
FYI: here are two non-unique games validated by Jacobi v0.7.5 to prove the legality of the diagram positions. 000 rights remain in b, while in a are retained until the penultimate move.
a) 1.e4 Sf6 2.a4 Sd5 3.exd5 Sc6 4.a5 Sb4 5.h4 Sd3+ 6.Ke2 Sxb2 7.g3 Sc4 8.Bb2 Sa3 9.Be5 Sxc2 10.Bxc7 Sb4 11.Sc3 Sa6 12.Se4 Sb8 13.Sg5 Sa6 14.Se6 Sb8 15.Sxd8 Sa6 16.Bb8 Sb4 17.Sxf7 Sa6 18.Sh6 Sc5 19.Ra4 Sa6 20.Rc4 Sc7 21.Rc6 Sa6 22.Rd6 Sb4 23.Sf3 Sa2 24.Sg5 Sb4 25.Se6 Sa2 26.Sxf8 Sb4 27.Sg6 Sa6 28.Sxe7 Sb4 29.Qc2 Sa6 30.Kd3 Sc7 31.Be2 Sa6 32.f4 Sc7 33.Rb1 Sa6 34.Rb5 Sc7 35.Kc3 Sa6 36.Kb2 Sc7 37.Ka1 Se6 38.Bg4 Sd8 39.Rf6 Sc6 40.Be6 Sd8 41.Sf7 Sc6 42.Sg5 Sd8 43.Qxc8 Rf8 44.Bg4 Rh8 45.Sf5 Rf8 46.Sd4 Rh8 47.Sde6 Rf8 48.Kb2 Rxf6 49.Ka1 Rh6 50.Bh5+ Rxh5 51.Sd4 g6 52.g4 a6 53.Qc1 Sc6 54.f5 Sxd4 55.Rb3 Sxb3+ 56.Ka2 Sxa5 57.Ka1 Sc6 58.Ka2 Se5 59.Ka1 Sf7 60.Ka2 Sxg5 61.Ka1 Sf7 62.Qc8+ Sd8 63.Qxd8+ Kf7 64. Qe8+ Kxe8
b) 51. … a6 52.Qc1 Se6 53.Qc2 Sxg5 54.f5 Sf3 55.g4 Sxd4 56.Rb3 Sxb3+ 57.Ka2 Sxa5 58.Qb1 Sb3 59.Qa1 Sxa1 60.Kxa1 g5
Corrects P1401480.
Henrik Juel: a) 1.fxg6 Txd5 2.Le5 0-0-0 3.g7 Th8 4.gxh8=DT#
b) 1.fxg6ep Txd5 2.Le5 0-0-0 3.g7 Th8 4.gxh8=DT# (2022-06-02)
Henrik Juel: a) is C+ Popeye 4.61, except for the promotion mate dual; no AP here
In b) Popeye with 'opt enp g6' gives the intended solution; here the castling is needed to rule out the possibility of Kf7xDe8 as last move
But how do we know that last move was not f6xg5 or h6xg5? (2022-06-02)
A.Buchanan: Hi Henrik thanks for examining this.
In a), the last move must have been Kxe8 to deal with checking piece. Otherwise black would have played e.g. b7-b5. If you forbid castling in Popeye you will see a completely different solution.
In b) hxg5 or fxg5 is too short to compete with b7-b5. (2022-06-02)
Henrik Juel: Yes, I missed b7-b5
Popeye with 'opt noc a8' gives this solution for a) 1.Ld6 Td8 2.fxg6 Txd5 3.g7 Th5 4.g8=D#
Very nice, with analysis in both parts (2022-06-02)
comment
Keywords: a posteriori (AP) (Type Petrovic), Maximummer, Castling (sg), En passant as key, Promotion (D,D/T), Valladao Task, Retro Strategy (RS)
Genre: h#, Retro, Fairies
Computer test: HC+ Popeye v4.87 for forward logic, Jacobi v0.7.5 to validate demo games & humans for non-trivial retro-logic
FEN: rB2k3/1p1p3p/p5p1/3P1P1r/6PP/8/3P4/K7
Input: A.Buchanan, 2022-06-02
Last update: A.Buchanan, 2022-06-03 more...
90 - P1401684
Velmurugan Nallusamy
SS027 The Hopper Magazine I01 24/12/2021
P1401684
(15+11) C+
PG in 9.5
Madrasi
1. h4 Sf6 2. h5 g5 3. hxg6ep Lh6 4. Txh6 0-0 5. Txh7 De8 6. Txf7 Dxf7 7. g7 Se8 8. gxf8=T+ Kg7 9. Th8 Kf6 10. Th1
play all play one stop play next play all
more ...
comment
Keywords: Unique Proof Game, Homebase (w), En passant, Pronkin Theme (T), Promotion (T), Castling (sk), Valladao Task, Phoenix (T), Madrasi
Genre: Retro, Fairies
Computer test: C+ Jacobi 0.7.5
FEN: rnb1n3/pppppq2/5k2/8/8/8/PPPPPPP1/RNBQKBNR
Input: A.Buchanan, 2022-06-08
Last update: Miguel Ambrona, 2023-07-26 more...
91 - P1406941
Marco Bonavoglia
Best Problems 105, p. 561, 01/2023
P1406941
(4+4)
h#2 a Posteriori
Ultrapatrouilleschach
1. dxe3ep 0-0-0+! 2. Kf7 d8=S#

R: 1. e2-e4
play all play one stop play next play all
Autor: "Le ultime mosse sono state del Re bianco (protetto dalla Ta1) o Be2-e4 protetto dal Ke1. Il nero prende en passant e il bianco deve giustificarlo a posteriori arroccando. Tema Valladao of course." [Zuletzt zog der weiße König (geschützt durch Ta1) oder Be2-e4 geschützt durch Ke1. [mri: oder Td1-a1] Schwarz schlägt en passant und Weiß muss es anschließend durch die Rochade rechtfertigen. Valladao-Thema natürlich.]
Posthum innerhalb eines Nachrufes auf Marco Bonavoglia veröffentlicht.

Antonio Garofalo: "Marco, mentre era in ospedale, mi ha inviato questi due problemi, uno augurale, l'altro per la competizione fairies. Sfortunatamente egli non può vedere i suoi lavori pubblicati, essendo deceduto nelle prime ore del 5 dicembre 2022..." [Marco schickte mir, während er im Krankenhaus war, diese beiden Probleme [dieses und P1406940], eines für seine [Neujahrs-]Wünsche (P1406940), das andere für den Wettbewerb, Abteilung Märchenschach. Leider kann er seine veröffentlichten Werke nicht mehr sehen, denn er verstarb in den frühen Morgenstunden des 5. Dezember 2022.]
Joost de Heer: C+ Popeye with 'opt enp e2e3e4'.
Too bad there isn't a try without castling. (2023-04-04)
comment
Keywords: En passant as key, Ultrapatrol, Valladao Task
Genre: h#, Retro, Fairies
Computer test: laut 'Best Problems' C+, aber Prüfprogramm nicht angegeben
FEN: 4k2r/3P4/2n5/8/3pP3/8/8/R3K3
Input: Mario Richter, 2022-12-30
Last update: Mario Richter, 2022-12-30 more...
92 - P1408358
Andrew Buchanan
10 Problemas 36, p. 1190, 10/2021
P1408358
(15+13) C+
PG in 14.5
1. e4 c5 2. Lb5 c4 3. Sf3 c3 4. 0-0 cxd2 5. c4 f6 6. Db3 d1=L 7. Lh6 Kf7 8. c5+ d5 9. cxd6ep+ Kg6 10. Se5+ Kh5 11. Le8+ g6 12. Lg7 Lh3 13. gxh3 Lg4 14. f3 Kh4 15. fxg4
play all play one stop play next play all
Objective: co-record shortest achievement of task, followed by artistic continuation.
Also version rnbqBbnr/pp2p1Bp/3P1pp1/4N2k/4P3/1Q5P/PP3P1P/RN1R2K1 PG in 14.0 mentioned in article. This offers different artistic continuation (with Pronkin instead of Ceriani-Frolkin).
more ...
comment
Keywords: Unique Proof Game, Valladao Task, Castling (wk), En passant, Promotion (l), Prenix (l), Ceriani-Frolkin Theme (l)
Genre: Retro
Computer test: HJ: C+ Stelvio 1.0
FEN: rn1qBbnr/pp2p1Bp/3P1pp1/4N3/4P1Pk/1Q5P/PP5P/RN3RK1
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-03-20 more...
93 - P1408359
Andrew Buchanan
9 Problemas 36, p. 1190, 10/2021
P1408359
(14+13) C+
PG in 12.0
1. e4 b5 2. e5 b4 3. Lb5 b3 4. Se2 bxc2 5. 0-0 cxb1=S 6. Dc2 f5 7. Dxc7 Kf7 8. Dc4 d5 9. exd6ep+ Kf6 10. Dxg8 Le6 11. d7 Dc8 12. d8=S Sd7
play all play one stop play next play all
Objective: co-record shortest achievement of task, followed by artistic continuation.
more ...
comment
Keywords: Unique Proof Game, Valladao Task, Castling (wk), En passant, Promotion (sS), Prenix (s), Phoenix (S)
Genre: Retro
Computer test: HJ: C+ Stelvio 1.0
FEN: r1qN1bQr/p2np1pp/4bk2/1B3p2/8/8/PP1PNPPP/RnB2RK1
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-03-20 more...
94 - P1408360
Andrew Buchanan
8 Problemas 36, p. 1190, 10/2021
P1408360
(13+13) C+
PG in 11.5
1. d3 e5 2. Sd2 e4 3. Sdf3 exf3 4. b4 fxe2 5. La3 exf1=S 6. Dg4 Ke7 7. 0-0-0 Kd6 8. b5+ c5 9. bxc6ep+ Kc7 10. Dxd7 Kb6 11. g4 Sg3 12. hxg3
play all play one stop play next play all
Objective: co-record shortest achievement of task, followed by artistic continuation.
more ...
comment
Keywords: Unique Proof Game, Valladao Task, Castling (wg), En passant, Promotion (s), Ceriani-Frolkin Theme (s)
Genre: Retro
Computer test: HJ: C+ Stelvio 1.0
FEN: rnbq1bnr/pp1Q1ppp/1kP5/8/6P1/B2P2P1/P1P2P2/2KR2NR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-03-20 more...
95 - P1408361
Andrew Buchanan
2 Problemas 36, p. 1189, 10/2021
P1408361
(15+13) C+
PG in 8.0
1. e4 Sf6 2. Ke2 Sd5 3. exd5 g5 4. d6 Lh6 5. dxc7 0-0 6. cxb8 Da5 7. Ke3 g4+ 8. f4 gxf3ep+
play all play one stop play next play all
Objective: record achievement of task. Promotion can be to either minor officer, but prefer to keep the "stem cell" to avoid arbitrary choice of non-standard material.
more ...
comment
Keywords: Unique Proof Game, Dummy Pawn (in diagram), Valladao Task, Golden Age (Dummy Pawn), Castling (sk), En passant
Genre: Retro
Computer test: HJ: with wSd8 C+ Stelvio 1.0
FEN: rn1P1rk1/ppp2p1p/3p1n1b/8/8/4Kp2/PPPP2PP/RNBQ1BNR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-08-04 more...
96 - P1408362
Andrew Buchanan
2 Problemas 36, p. 1189, 10/2021
P1408362
(15+13) C+
PG in 8.0
1. e4 Sf6 2. Ke2 Sd5 3. exd5 g5 4. d6 Lh6 5. dxc7 0-0 6. cxb8 Da5 7. Ke3 g4+ 8. f4 gxf3ep+
play all play one stop play next play all
Objective: record achievement of task. Promotion can be to any officer, but prefer to keep the "stem cell" to avoid arbitrary choice of non-standard material.
more ...
comment
Keywords: Unique Proof Game, Dummy Pawn (in diagram), Valladao Task, Golden Age (Dummy Pawn), Castling (sk), En passant
Genre: Retro
Computer test: HJ: with wSb8 C+ Stelvio 1.0
FEN: rPb2rk1/pp1ppp1p/7b/q7/8/4Kp2/PPPP2PP/RNBQ1BNR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-08-04 more...
97 - P1408363
Andrew Buchanan
3 Problemas 36, p. 1189, 10/2021
P1408363
(15+13) C+
PG in 8.0
1. d4 Sf6 2. Kd2 Se4+ 3. Ke3 Sc5 4. dxc5 g5 5. c6 Lh6 6. cxb7 0-0 7. bxc8 g4+ 8. f4 gxf3ep+
play all play one stop play next play all
Objective: record achievement of task. Promotion can be to any officer, but prefer to keep the "stem cell" to avoid arbitrary choice of non-standard material.
more ...
comment
Keywords: Unique Proof Game, Dummy Pawn (in diagram), Valladao Task, Golden Age (Dummy Pawn), Castling (sk), En passant
Genre: Retro
Computer test: HJ: with wSc8 C+ Stelvio 1.0
FEN: rnPq1rk1/p1pppp1p/7b/8/8/4Kp2/PPP1P1PP/RNBQ1BNR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-08-04 more...
98 - P1408364
Andrew Buchanan
4 Problemas 36, p. 1189, 10/2021
P1408364
(15+12) C+
PG in 8.0
1. d4 Sc6 2. Kd2 Se5 3. dxe5 Sf6 4. exf6 g5 5. fxe7 Lh6 6. exd8 0-0 7. Ke3 g4+ 8. f4 gxf3ep+
play all play one stop play next play all
Objective: record achievement of task. Promotion can be to either minor officer, but prefer to keep the "stem cell" to avoid arbitrary choice of non-standard material.
more ...
comment
Keywords: Unique Proof Game, Dummy Pawn (in diagram), Valladao Task, Golden Age (Dummy Pawn), Castling (sk), En passant
Genre: Retro
Computer test: HJ: with wSd8 C+ Stelvio 1.0
FEN: r1bP1rk1/pppp1p1p/7b/8/8/4Kp2/PPP1P1PP/RNBQ1BNR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-08-04 more...
99 - P1408365
Andrew Buchanan
5 Problemas 36, p. 1189, 10/2021
P1408365
(15+14) C+
PG in 8.0
1. f4 e6 2. f5 Lc5 3. f6 Se7 4. fxe7 Lb6 5. exd8 c5 6. Kf2 0-0 7. Ke3 c4+ 8. d4 cxd3ep+
play all play one stop play next play all
Objective: record achievement of task. Promotion can be to either minor officer, but prefer to keep the "stem cell" to avoid arbitrary choice of non-standard material.
more ...
comment
Keywords: Unique Proof Game, Dummy Pawn (in diagram), Valladao Task, Golden Age (Dummy Pawn), Castling (sk), En passant
Genre: Retro
Computer test: HJ: with wSd8 C+ Stelvio 1.0
FEN: rnbP1rk1/pp1p1ppp/1b2p3/8/8/3pK3/PPP1P1PP/RNBQ1BNR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-08-04 more...
100 - P1408366
Andrew Buchanan
6 Problemas 36, p. 1189, 10/2021
P1408366
(15+14) C+
PG in 8.0
1. f4 d5 2. f5 Ld7 3. f6 Lc6 4. fxe7 Sd7 5. exf8 Dg5 6. Kf2 0-0-0 7. Kf3 d4+ 8. e4 dxe3ep+
play all play one stop play next play all
Objective: record achievement of task. Promotion can be to either minor officer, but prefer to keep the "stem cell" to avoid arbitrary choice of non-standard material.
more ...
comment
Keywords: Unique Proof Game, Dummy Pawn (in diagram), Valladao Task, Golden Age (Dummy Pawn), Castling (sg), En passant
Genre: Retro
Computer test: HJ: with wSf8, C+ Stelvio 1.0
FEN: 2kr1Pnr/pppn1ppp/2b5/6q1/8/4pK2/PPPP2PP/RNBQ1BNR
Input: A.Buchanan, 2023-03-19
Last update: A.Buchanan, 2023-08-04 more...
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