Die Schwalbe

21 problem(s) found in 5431 milliseconds (displaying 21 problem(s)). [COMMENTDATE>=20200919 AND G='2#' AND K='En passant als Schlüssel'] [download as LaTeX]

1 - P0001310
Dragan Petrovic
182 Europe Echecs 107 01/1968
4. Preis
P0001310
(13+14) C+
#2 (AP)
1. gxf6ep! droht 2. 0-0#! (2.Kf2#?)
R: 1. f7-f5 f6xDe7,f6xTe7 etc
play all play one stop play next play all
Wh caps: fxe7, hxg5
Bl caps: axbxc2, wBf1
If wK castling right remains, the only way to give White a prior move is to retract f7-f5, so ep would be on.
The key threatens (inter alia) 2. 0-0#/Kf2#, and both remain whatever Black plays, so the castling retro-justification for ep can never be disrupted.
R: 1. S~a3? a3-a4? blocks wT from retracting to home square if wK castling right remains.
Dragan Petrovic: Author is Dragan T. Petrovic (2007-12-02)
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comment
Keywords: En passant as key, Castling (wk), a posteriori (AP) (Type Petrovic)
Genre: Retro, 2#
Computer test: HC+ Popeye v4.87 & simple retro-logic
FEN: 4r3/1p2P1n1/4p2B/b1pp1pPb/P5pp/nPP5/Q1pPP1P1/N1k1K2R
Reprints: (50) Problem 144-147 12/1971
(38) Mat Plus 12 10-12/2009
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2023-07-21 more...
2 - P0001859
William A. Langstaff
The Chess Amateur 1922
P0001859
(5+3) C+
#2
If Black can castle, e.p. is ok:
1. hxg6ep! 0-0 2. h7#
1. ... Tf8,Kf8 2. Td8#
Otherwise Black can't castle:
1. Ke6! ... 2. Td8#
play all play one stop play next play all
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comment
Keywords: Cant Castler, Partial Retro Analysis (PRA), Castling (sk), En passant as key
Genre: Retro, 2#
Computer test: HC+ Popeye 4.61 & trivial retro-logic
FEN: 4k2r/8/5B1P/3R1KpP/8/8/8/8
Reprints: (D17) feenschach 27 04/1975
RA64 diagrammes 27 05-06/1977
(1) Die Schwalbe 86 04/1984
Razem 34 23/08/1987
(I) diagrammes 15 07-09/1994
(10) Die Schwalbe 241 02/2010
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2021-11-30 more...
3 - P0003817
Jean Oudot
Nation Belge 1956
P0003817
(14+12) C+
#2
1. cxd6ep
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paul: Since the wB couldnt leave c1, the captured piece on b6 is the promoted wPh2. If last black move was f7-f5, then h-Pawn captured four pieces to promote on d8, among which bRh8, impossible. Thus, the h-Pawn could only have been promoted from f7 and therefore d7-d5 remains as the last move. (2011-07-02)
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comment
Keywords: En passant as key
Genre: Retro, 2#
Computer test: C+ Popeye 4.61
FEN: qrRNkb2/PpQ1p1pp/1pp1R3/2PpKpP1/6N1/7B/1P1PPP2/8
Reprints: RA15 diagrammes 15 06/1975
(51) Mat Plus 12 10-12/2009
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-11-27 more...
4 - P0004647
Branko Pavlovic
International Solving Match 1947
P0004647
(7+3)
#2
1. Kg6,Sf8 g3 2. f7#
1. fxg6ep? because e.g. R: 1. Kf7-g8 gxSh8=S+ can be history
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Paulo Roque: NL : 1. Sf8! g3 2. f7# (2009-08-22)
Henrik Juel: The organizers of solving matches in the old days liked tricky problems. Here there are two tricks: The 'obvious' e.p. key does not work (because last move could be Kf7-g8), and there are two solutions. (2009-08-22)
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Keywords: En passant as key
Genre: Retro, 2#
FEN: 6kN/3N3R/5P1B/5PpK/6p1/8/8/8
Reprints: (10) Problem 198-201 07/1980
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2021-11-01 more...
5 - P0006655
Thomas R. Dawson
The Chess Amateur 1925
P0006655
(7+3) C+
#2
1. fxg6ep+ Kg5 2. Lh4#
R: 1. g7-g5
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comment
Keywords: En passant as key
Pieces: du = Grasshopper (G)
Genre: Retro, 2#, Fairies
Computer test: HC+ Popeye 4.61 after very simple analysis
FEN: 8/5*2Q1K/5P1P/5Ppk/6p1/6B1/6N1/8
Reprints: 115 Caissa's Wild Roses 1935
Input: Gerd Wilts, 1996-07-16
Last update: A.Buchanan, 2021-05-03 more...
6 - P1020121
Philipp von Klett

P1020121
(9+4) C+
#2
1. gxf6ep (ZZ) gxf6 2. Sxf6#
1. ... Kxg4 2. Le2#
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Klett: Statt der Dc1 würde auch ein Läufer genügen,; die Dame in ihrer freien Stellung erschien uns aber hier ausnahmsweise angemessener.

Für ein Problem, in dem die wD tatsächlich notwendig ist bringt Klett die P0002091.
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comment
Keywords: Brian Stephenson Collection (4961), En passant as key
Genre: 2#, Retro
Computer test: Henrik Juel (2021-02-20): C+ Popeye 4.61
FEN: 8/6p1/4P1P1/4KpPk/6Nb/3B4/5P2/2Q4R
Reprints: 2 Schachprobleme [Klett] 1878
Sammlung leichterer Schachaufgaben II , p. 6, 1882
96 Schackproblem [Geijerstam] , p. 7, 1908
50 Westdeutsche Landeszeitung 11/12/1927
263 La Suisse Liberale 31/12/1928
29 Volksstimme (Magdeburg) 29/06/1930
Kleine Volks-Zeitung (Wien) 16/05/1938
29 Der Schachzug (FV Schach Berlin) 23 01-02/1978
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2023-03-24 more...
7 - P1020144
Josef Kling
23 The Chess Euclid 1849
P1020144
(6+6)
#2
1. axb6ep+ Kb1 2. 0-0#
1. ... Da7 2. Kf2#
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in 'Le Pion' fälschlich wBa4 ("1 - R 1 R ... 5 - P 4 TD ...")

Nach heutigen Konventionen ist der Ep-Schlag unzulässig, man beachte aber:
Kling im 'Chess Euclid' zur Intention dieser Aufgabe: "This problem I have compossed expressly to shew the error the modern composers of problems have committed, in introducing the system of castling in the ends of games. In this problem I consider I have as good a reason to say that Black has just moved his Q. Kt. P. [b5] two squares as that White has not moved his K. R. or K."
James Malcom: I found this hidden ancient, another that rode the rails of the unjustified en passant key. (2020-12-28)
SP: Unsound in its own terms, as, whatever Black plays (Kb1/Qa7),
castling is never forced due to 2.Kf2#
I use the keyword "non-analytic en passant key" for such problems. (2023-08-21)
A.Buchanan: The composer's stated intention seems to be that (1) ep is ok (2) castling is not ok. In these terms, the problem is sound (2023-08-22)
comment
Keywords: Brian Stephenson Collection (4985), En passant as key, Castling (wk), En passant, Castling as mating move, Golden Age
Genre: 2#
FEN: R7/7q/7r/Pp6/5p1r/7P/4Q3/k3K2R
Reprints: 458 Dubuque Chess Journal 35 01/1873
P10 Le Pion 01/05/1873
Input: Brian Stephenson, 2004-08-12
Last update: A.Buchanan, 2023-08-22 more...
8 - P1054640
Jaques Fulpius
10038 Schweizerische Schachzeitung 09/1968
P1054640
(10+5) C+
#2
1. dxe6ep! Lxb2,Ld3 2. Da8#
1. ... c3 2. Tb3#
play all play one stop play next play all
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comment
Keywords: Brian Stephenson Collection (39688), En passant as key, En passant in the forward play, Blocknutzung, Deckungsverlust
Genre: 2#, Retro
Computer test: Juel: C+ Popeye 4.61 clearly, last move was e7-e5
FEN: 8/8/3P1B2/1BNPpK2/1Ppp4/k7/NR4Q1/b7
Reprints: 20 Kunstschach in der Schweiz , p. 19, 1980
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2023-11-12 more...
9 - P1106295
Thomas R. Dawson
776 Deutsche Schachblätter 15/12/1912
P1106295
(14+10)
#2
1. hxg6ep Lg5 2. Dxg5#
R: 1. g7-g5 Te3-e7+ 2. Kg5-h6+ Lf5-h7+
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A.Buchanan: I posted this in Facebook today - Lion Xray asked if wBh2 can be removed - I think it can. (2021-02-16)
Henrik Juel: Without Ph2 last move could also be f6xg5, it seems (2021-02-16)
Mario Richter: I too think the wPh2 can be removed, since then f6xg5 as Black's last move is still impossible (think of wPf2+h2) (2021-02-16)
A.Buchanan: With only one Wh unit unaccounted for, bPg & bPh never left their files. So wPh5 must have captured in. Either fxgxh or hxgxh. In the former case, the original wPh was "waylaid" captured unpromoted on its own file. In the latter case, wPf must have promoted on f8 without capturing. I.e. bPf captured to clear the way. However Black’s last move can’t have been f6xg5, because wPf would not have had a free path to march to f8. The count is correct in either case. (2021-02-17)
A.Buchanan: Another possibility is that wPf was waylaid, to allow bPf to promote on f1. Again, Black’s last move was not f6xg5. (2021-02-17)
A.Buchanan: "Superseded by" was replaced by "better version". I am not averse to improvements in terminology, but here I have reverted, for the following reasons: (1) A keyword should describe the compositions which are tagged by it. "Better version" does not describe a problem it tags, but indicates that *another* problem is the "better version". (2) A superseding problem may not be a version, but could be radically different matrix tackling a record or task. I have left the new German term "bessere Version" alone, and put this comment in the keyword text. (2021-02-18)
comment
Keywords: En passant as key, Superseded by (P1386614)
Genre: 2#, Retro
FEN: 3KN3/qrp1R2B/pp5k/Q5pP/PPP4b/1p4Pp/1PP4P/2B5
Input: Frank Müller, 2010-05-29
Last update: A.Buchanan, 2021-02-18 more...
10 - 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#
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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...
11 - P1201388
Arthur Poplawski
Deutsche Schachzeitung , p. 319, 10/1888
P1201388
(15+14) C+
#2
1. e5xd6ep+
1. ... e5 2. Taxf7#
1. ... f6 2. Dxf6#
1. ... Kxf8 2. Dh8#
play all play one stop play next play all
'DSZ': "Die untenstehende Stellung theilt uns ein Herr A. P. in Zürich zur Veröffentlichung mit. Wir möchten jedoch noch an das Diagramm für unsere Löser eine Warnungstafel anhängen, wie man solchen häufig in zoologischen Gärten begegnet: 'Achtung, ich beisse!"
Henrik Juel: Black captured [Lc1] with an officer, and the black pawns never captured. White captured d3xLe4 and f2xSg3, so all seemingly possible last moves by Black fail because of an illegal check, except d7-d5.
1.exd6ep+ f6/Kxf8 2.Dxf6/Dh8# (2011-09-04)
Ladislav Packa: 1.-e5 2.Raxf7# (2011-09-04)
A.Buchanan: Why not R: 1. Kf6-g7 d4xe5+ (2020-07-05)
Kevin Begley: You can not legally retract -1.Kf6-g7 d4xe5+, when you consider the only two units black is missing are a light-squared bishop and a knight. The Knight must have been captured on g3 (light squared bishop can not die there). Nor can black's light-squared bishop have been captured on e5. (2020-07-05)
A.Buchanan: I shouldn't post before breakfast (2020-07-05)
Lutz Neweklowsky: The chess problem is o.k. , because the last 2 moves were : 1.fxNg3 Bf3e4 2.dxBe4 d5 and 3.e5xd6ep+ cheers Lutz Neweklowsky (2023-06-10)
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Keywords: En passant as key
Genre: 2#, Retro
FEN: 1n3R2/R3ppkp/p1N3Br/rpKpP1pP/q1p1P2N/1PQ3P1/P1P3Pb/8
Input: Mario Richter, 2011-08-27
Last update: Mario Richter, 2021-03-26 more...
12 - 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#
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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...
13 - P1321497
Pal Benko

P1321497
(5+5) C+
#2
1. axb6ep cxb6+ 2. Sxb6#
1. ... Sxc8,Sxc6 2. b7#
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In 'My Life' steht als Originalquelle "Games 1996" - welche Publikation damit gemeint ist, ist unklar. In den Index-Files des 'Games and Puzzle Journal' [Jelliss] taucht der Name Benkö nicht auf, laut 'Chess Periodicals' [Felice] gab es zwar einige Magazine, die vom Namen her passen könnten (s. S.90ff, Einträge 1016ff), deren Publikationszeitraum aber jeweils weit vor 1990 endet.

Figurenkranz 3×4 a5c8
Henrik Juel: C+ by Popeye 4.61
Strategems started in 1998, I believe (2016-06-19)
Frank Müller: Die Quelle kann ich auch nicht prüfen. es könnte auch The Games and Puzzles Journal sein. Das gab es zumindest in 1996. (2016-06-19)
Mario Richter: Vielleicht kann jemand mit Zugriff auf alte 'Strategems'-Ausgaben mal schauen, was dort als Originalquelle zu Problem P1000507 angegeben ist - das könnte helfen ... (2016-06-20)
James Malcom: As far as I can see it, it does not appear in the archived issues of The Games and Puzzles Journal: http://www.mayhematics.com/p/p.htm (2021-01-03)
Anton Baumann: vergl. P1402037 (2023-05-15)
comment
Keywords: En passant as key, Symbol problem
Genre: 2#, Retro
Computer test: Popeye 4.61 + analysis
FEN: kbN5/n1p5/B1N5/PpK5/8/8/8/8
Reprints: 284 My life, games and compositions 2003
Input: Mario Richter, 2016-06-19
Last update: A.Buchanan, 2023-05-15 more...
14 - P1375286
Andrew Buchanan
James Malcom

PDB Website 30/4/2020
P1375286
(6+3)
#2
(-:
1. dxc7ep! b4 2. c8=D,T#

R: 1. ... c8-c6?! and earlier c8=sB?!
play all play one stop play next play all
Supersession of P1380851

Superseded by P1380851

The 2018 FIDE laws state: "3.7.2 on its first move the pawn may move as in 3.7.1 or alternatively it may advance two squares along the same file, provided that both squares are unoccupied."

Hence Black's newborn 8th rank pawn, which has never been moved before, reserves the right to commence a double-step on its first move, and likewise White receives the right to capture it en passant as they do with a 7th rank pawn.
Henrik Juel: This un-dummy-pawn is like a pawn created on c8 by the Einstein condition
The retroplay looks wrong, what about 1... d8-d6!? 2.d7-d8=sB!? c6xYb5 (2020-04-30)
James Malcom: That makes much more sense Henrik. I have edited it accordingly. (2020-04-30)
A.Buchanan: You don't like Adrian's (: haha? What about :) then? In heraldic terms, it would be described as "regardant". See 270 on https://www.heraldica.org/cgi-bin/atlas.pl?12. I don't know the word for "non-regardant", which is the default direction for the head, e.g. most of the others on that page.
We could replace wBa6a7 with wSa6, but alas having the 3rd knight is non-thematic & distracting. The other thing I would've liked to do is empty b2 so the promotion is forced to be to D. Such a tiny problem should have precision promotion. Needs more thinking. (2020-05-01)
James Malcom: UPDATE: The position has been edited to have one less piece and a precise queen promotion. (2020-10-12)
A.Buchanan: There is dialogue here which is now orphaned by a change of diagram with new matrix. Suggest we revert to the older diagram and mark it superseded by a new PDB entry here (2020-10-12)
James Malcom: I agree-it is now done. (2020-10-12)
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comment
Keywords: En passant as key, Joke, Joke promotion (b), Tolerated dual promotion (D/T), Promotion (D/T), Superseded by (P1380851)
Genre: 2#, Retro
FEN: k7/PN1N4/PKpP4/1p6/8/8/8/8
Input: James Malcom, 2020-04-30
Last update: A.Buchanan, 2022-09-18 more...
15 - P1380992
Otto Gross
1 Aufbau (New York) 30/04/1943
P1380992
(13+5) C+
#2
1. gxf6ep! droht 2. Dg5#
1. ... gxh6 2. Sxh6#
1. ... Sf3+ 2. exf3#
1. ... Sxg2 2. e7#
1. ... Sxg6+ 2. Dxg6#
1. ... gxf6+ 2. Sxf6#
play all play one stop play next play all
'Aufbau': Das Problem des en-passant-Schlagens ist in unserer Aufgabe nicht die Schwierigkeit, der wir besonderen Wert beimessen, sondern es handelt sich lediglich darum, die Korrektheit der Stellung nachzuweisen, nämlich warum zuletzt nur f7-f5 von Schwarz geschehen sein kann.
f6-f5 oder Sh4-f3 kann nicht geschehen sein, sonst hätte der weisse König im Schach gestanden; die Möglichkeit, dass evtl. ein dritter Springer, in welchen der fehlende weisse Bauer umgewandelt wurde, bei der Placierung des schwarzen Königs auf g3 durch ein Abzugsschach (Sf2-g4 Kg3xg4) ermöglicht haben könnte, fällt fort, da der fehlende Bauer nur ein weisser Läufer geworden sein kann, der jetzt auf c8 steht. Der bei Beginn des Spiels vorhanden gewesene weisse Läufer muss auf seinem Platz geschlagen worden sein, da Be2 und g2 seine Entwicklung verhinderten.
SCHRECKE: Umwandlungsläufer wLc8! (2020-10-16)
Henrik Juel: C+ Popeye 4.61, after analysis proving that last move was f7-f5 (2020-10-16)
comment
Keywords: En passant as key, Obvious promotion
Genre: 2#, Retro
Computer test: Popeye 4.61
FEN: 2B3N1/2P3p1/4P1PQ/4KpPp/5Pkn/8/3NP1P1/4B3
Input: Mario Richter, 2020-10-16
Last update: Alfred Pfeiffer, 2020-10-17 more...
16 - P1381271
I. I. Lyon
No. 9 American Chess Review Vol. 1, p. 27, 8/1886
P1381271
(6+4)
#2
1. exf6ep! droht 2. Sc6,Se6#
1. ... Sd6,gxf4 2. Se6#
1. ... Sc7,Sxf6,Sg7 2. Sc6#
play all play one stop play next play all
https://books.google.com/books?id=y6uBo98GjoUC
Henrik Juel: The ep key is unjustified (2020-10-24)
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comment
Keywords: En passant, En passant as key, Joke
Genre: 2#
FEN: 3kn3/8/1N6/4PppB/3N1B2/8/3K4/8
Input: James Malcom, 2020-10-24
Last update: A.Buchanan, 2020-10-25 more...
17 - P1386614
Thomas R. Dawson
Lion Xray
Andrew Buchanan

PDB Website 19/02/2021
TRD, version LX & AB
P1386614
(13+9) C+
#2
1. hxg6ep+ Lg5 2. Dxg5#
R: 1. g7-g5 Te3-e7+ 2. Kg5-h6+ Lf5-h7+ 3. Kf6-g5 Sd6-e8+
play all play one stop play next play all
Black has captured 3 white units. dxcxb accounts for 2. With only one left over, we know that bPh3 never captured. So to explain wPh4, White must have played fxgxh or hxgxh. Combined with dxcxb & exdxcxb, that accounts for all of White's captures.
(a) If White played fxgxh, then the original [wPh] was "waylaid" by an officer, without promoting or capturing.
(b) If White played hxgxh, then the original [wPf] did not capture. We know that [bPf] or [bPg] promoted, using at most one capture.
(b.1) If Black did capture fxg or fxe, then [wPf] did promote to make the balance, and Black's last move can't have been fxg, or the f-file would be blocked to wP.
(b.2) If Black didn't capture fxg or fxe, then [wPf] was waylaid to clear the way for [bPf] to promote.
We don't know which of these three possibilities happened, but in every case:
(1) All captures are accounted for (so e.g. Kg5xSh6 was not possible).
(2) Black did not just play f6xg5.
If Black just played g6-g5, retract prior checking moves and discover retropat as g6 is blocked preventing discovered check by wB now on h7. By elimination, last move was g7-g5 and ep key is ok.
Removes 2 pieces from P1106295, and enriches the retro logic
Henrik Juel: Nice clean-up and careful retro argumentation (2021-02-18)
A.Buchanan: Thanks Henrik - in fact I've just seen that one can uniquely retract a couple of single moves further, see the animation (2021-02-19)
comment
Keywords: En passant as key, Last Moves? (6)
Genre: 2#, Retro
Computer test: HC+ retro musing + Popeye v4.85
FEN: 3KN3/rPp1R2B/pp5k/Q5pP/PPP4b/1p4Pp/1P6/2B5
Input: A.Buchanan, 2021-02-18
Last update: A.Buchanan, 2021-04-16 more...
18 - P1395008
Cor Goldschmeding
4 International Solving Match 1946
P1395008
(11+5)
#2
1. cxb6ep? droht 2. Dxe7#
but R: 1. Kg6xBf6 g5xf6ep 2. f7-f5 Lf3-e4+,~ equally possible history
play all play one stop play next play all
s. Anmerkung zu P1395005
Autorangabe aus der YACPDB (id=241476) übernommen
Henrik Juel: Last move was clearly b7-b5
1.cxb5ep thr. 2.Dxe7#
HC+ Popeye 4.61 (2021-10-29)
Mario Richter: As stated, I do not know the intended solution, but I think 1. cxb5ep? is only a trap.
R: 1. ... Kg6xPf6 2. g5xf6ep++ f7-f5 3. Lf3-d4+ is a legal retraction sequence, so the ep-key is not justified. (2021-10-30)
Henrik Juel: You are right, Mario (as usual, I might add) (2021-10-30)
comment
Keywords: En passant as key, En passant in the retro play, no solution
Genre: 2#, Retro
FEN: 8/4p1pp/P1N1Pk1N/KpP5/4BP2/Q1P3R1/8/8
Input: Mario Richter, 2021-10-29
Last update: A.Buchanan, 2021-10-30 more...
19 - P1395505
Thomas R. Dawson
Johan Barendregt

De Schaakwereld 1937
TRD, correction JB
P1395505
(15+9) C+
#2
1. axb6ep+ Kxe3 2. De2#
R: 1. b7-b5 2. Sc4-e3+ Ke3-d3+ 3. Sb6-c4+ d3xTc2
play all play one stop play next play all
Correction of P1395488
Henrik Juel: Black captured d3xTc2 and promoted on h1
White captured bxPa, d6xc7, exd, fxe, and h2xPg3xf4xe5
R: 1... b7-b5 2.Sc4-e3+ Ke3-d3+ 3.Sb6-c4+ d3xTc2
Yet another way to motivate the double step b7-b5
Solution 1.axb6ep+ Kxe3 2.De2# (2021-11-07)
comment
Keywords: En passant as key
Genre: 2#, Retro
Computer test: HC+ Popeye v4.87 & simple retro-logic
FEN: 2R5/2P1p3/B1pP1N2/Pp2P1K1/4P3/P1PkN3/1Bpb2P1/1nrQn3
Reprints: Tim Krabbé's Website 2001
MatPlus.net Forum 2021
Input: A.Buchanan, 2021-11-07
Last update: A.Buchanan, 2021-11-07 more...
20 - P1395678
N. Bania
4 International Solving Match 1948
P1395678
(12+10)
#2

1. dxe6ep? aber zuletzt war auch d6xc5 möglich, also ist der ep-key nicht gerechtfertigt
Henrik Juel: Black captured all 4 missing white men with axb, dxc, and fxgxPh-h1=L
White captured all 6 missing black men with cxbxa, dxc, exd, and fxexd
Last move was not e7-e6 ([Lf8]), so it was c7-c5 or d6xc5
1.dxc6ep? is not justified, and the problem is unsolvable (2021-11-10)
comment
Keywords: no solution, En passant as key, Obvious promotion (l)
Genre: 2#, Retro
FEN: kB6/Pp4pp/4p3/PKpP4/1pPP4/2p2B2/nP4PQ/2N4b
Input: Mario Richter, 2021-11-10
Last update: Alfred Pfeiffer, 2021-11-11 more...
21 - P1399767
A. Mittelmann
3368 Wiener Schach-Zeitung 2 01/1937
P1399767
(7+7)
#2
1. fxe6ep fxe6+ 2. Sxe6#
1. ... Txg7 2. e7#
1. ... Kxg7 2. Txf7#
play all play one stop play next play all
Henrik Juel: cooked
The ep capture key is not justified, because last move could be Ke7-f8 (2022-03-13)
Henrik Juel: Replacing wTd6 with a white pawn would fix the ep issue,
but it gives the dual 1... Txg7 2.e7,Td8# (2022-03-13)
comment
Keywords: En passant as key
Genre: Retro, 2#
FEN: 5krr/3R1pNp/3R1N1p/3KpP1P/8/8/8/8
Input: Rainer Staudte, 2022-03-13
Last update: Rainer Staudte, 2022-03-13 more...
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