2024 problem(s) found in 1063 milliseconds (displaying 100 problem(s)). [COMMENTDATE>=20181210]

1 - P0000033
S. N. Ravishankar
5467v Die Schwalbe 98 04/1986
P0000033
(5+3) cooked
#1 vor 14
VRZ, Typ friedlich
R: 1. Tg1-f1 2. Tf2-f3 Te2- 3. Te1-g1 4. Te2-f2 Ta2- 5. Ta1-e1 Tb2-a2 6. Tb1-a1 Tc2-b2 7. Tc1-b1 Td2-c2 8. Tg1-c1 Tc2-d2 9. Td2-e2 Tb2-c2 10. Tc2-d2 Ta2-b2 11. Tb2-c2 g3-g2 12. Lg2-h3+, dann 1. Th1#
play all play one stop play next play all
Cook: Kurzlösung:
R: 1. Tg1-f1 droht 2. Tf1-f3, dann 1. Th1#
R: 1. Tg1-f1 Tf2-g2 2. Tf1-g1, dann 1. T3xf2#
(Mario Richter)
Mario Richter: So wie abgebildet, sollte die Problemno. nicht '5467v' sein.
Die Verbesserung (also das 'v') scheint erst später erschienen zu sein.
Das Diagramm ist kurzlösig durch: R: 1. Tg1-f1 (dr. 2. Tf1-f3, dann 1. Th1#) Tf2-g2 2. Tf1-g1, dann 1. Tf3xf2#. (2011-8-18)
Alfred Pfeiffer: Dies ist schon eine Veränderung des Originals. Wo die (in der LB bereits erwähnte) "Korrekturfassung" erschien, ist unklar. (2018-1-16)
S N Ravi Shankar: Given Version of the problem is incorrect. bRg2 should be on f2 and a bP should be placed on g2. Stipulation is -12 and #1.
Solution is
-1. Rg1! Rb2 (say) -2. Rf2 Re2! -3.Re1! Rb2 (say) -4. Re2! Ra2!(-4 ... Rd2? -5. Rg1! as in text)
-5. Ra1! Rb2 -6. Rb1 Rc2 -7. Rc1 Rd2 -8. Rg1! Rc2 -9. Rd2! Rb2 -10. Rc2 Ra1 -11. Rb2 g3 -12. Bg2
and now 1. Rh1# (2019-1-2)
comment
Keywords: Defensive Retractor, Type Pacific
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-1-17 more...
2 - P0000108
Andrey Frolkin
6272 Die Schwalbe 111 06/1988
1. Lob
P0000108
(30+0) C+
Färbe die Steine!
BP in 19,0
1. h4 d6 2. Th3 Sd7 3. Tb3 Sdf6 4. Tb6 axb6 5. f4 Ta3 6. Kf2 Th3 7. a4 Th1 8. Ta3 Lh3 9. Tg3 Dd7 10. Tg6 hxg6 11. a5 Th5 12. a6 Ta5 13. h5 Ta1 14. h6 Da4 15. h7 b5 16. h8=T Sh7 17. a7 f6 18. a8=T+ Kf7 19. Ta7 Dd4+
play all play one stop play next play all
Henrik Juel: C+ by Natch 3.1 (16 min.)
The colored position has black Ta1,h1 and Pb5,g6, and white Ta7,h8, otherwise 'natural' (2018-12-7)
François Labelle: Henrik, did you really test all 2^30 possible colorings with Natch, or did you use human deductions to reduce the possibilities (making this HC+), or did you only test the intended coloring (making this a partial C+)? (2018-12-9)
Mario Richter: I do not think that it is necessary to check all 2^30 colorings, since the color of the pawns on files c,d,e and f is completely determined. This and more restrictions on the set of potentially possible colorings may be derived from insights presented in an article "Aggregierte Schlagbilanz" by Frolkin & Kornilov, feenschach 130, p.411ff. Since the mechanisms presented there can at least partially be implemented in a little computer program, even a "full C+" label for this problem is not out of reach ... (2018-12-10)
Henrik Juel: I only tested the intended coloring, Francois,
so the C+ label is not justifiable
In the other coloring proof games I write something like
The colored position was C+ by Natch

Mario is right, of course, in that not all colorings need testing; but still the number is very large
This genre is somewhat messy; at first I thought that the solver could determine the coloring, but this is clearly not the case; also, the intention is not
'color the men such that a correct proof game in 19 results' (2018-12-11)
A.Buchanan: Henrik: so what exactly should the stipulation be for clarity? (2018-12-12)
comment
Keywords: Unique Proof Game, Coloring problem, under-promotion (TT), Phoenix
Genre: Retro
Computer test: Natch 3.1 (16 min.)
Reprints: 158 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-7 more...
3 - P0000132
Nikita M. Plaksin
6578 Die Schwalbe 116 04/1989
2. ehrende Erwähnung
P0000132
(8+12)
Zeige, daß im Verlauf des Retrospiels zwingend die Möglichkeit zum ep-Schlag bestand!
Madrasi
paul: The stipulation in English: Show that, in the course of the retro game, the possibility for the en passant move existed! Madrasi (2019-1-13)
comment
Keywords: Madrasi, En passant
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2012-7-8 more...
4 - P0000143
Nikita M. Plaksin
6689 Die Schwalbe 118 08/1989
4. Lob
P0000143
(13+9)
Löse die Stellung auf!
Madrasi RI
R: 1. Se6xDd8 d2xTe1=L 2. Tb1-e1 c3xTd2 3. Tb8-b1 b4xTc3 4. b7-b8=T ... 5. a6xTb7,a6xSb7
play all play one stop play next play all
paul: If 4. -b5-b4 5.a6xBishop b7? Bc8-b7, then Black will be retro-stalemated. To unlock the position, the retro-play must be: Rf2 - Rg8 - g7-g8=R - Ph6xRg7 - Ph5 -Pg4xSh5(bSg3-h5), Rh1 - Rg8 - g7-g8=R - Ph6xRg7 - Ph5, Sh3-g5, Pg7-g5, Kg6-f7, Pf4-f5+, bBf8 was captured at home. (2019-1-13)
comment
Keywords: Madrasi (Rex inklusive)
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-6 more...
5 - P0000236
Karlheinz Bachmann
7437 Die Schwalbe 130 08/1991
P0000236
(3+1) cooked
BP in 16,0
Zeroposition
a) Kf8 nach g8
b) Lg5 nach g2
a) 1. Sf3 e5 2. Sxe5 Df6 3. Sxd7 Dxb2 4. Sxf8 Dxb1 5. Sxh7 Txh7 6. Txb1 Txh2 7. Txb7 Txg2 8. Txa7 Txf2 9. Txc7 Txf1+ 10. Txf1 Txa2 11. Tfxf7 Txc2 12. Txc8+ Kxf7 13. Txb8 Txd2 14. Txg8 Txd1+ 15. Kxd1 g5 16. Lxg5 Kxg8
b) 1. Sc3 d5 2. Sxd5 Dd6 3. Sxe7 Dxh2 4. Sxc8 Dxg1 5. Sxa7 Txa7 6. Txh7 Txa2 7. Txh8 Txa1 8. Txg8 Txc1 9. Txg7 Txc2 10. Txf7 Txb2 11. Txc7 Txd2 12. Txb7 Txd1+ 13. Kxd1 Dxf2 14. Txb8+ Ke7 15. Txf8 Dxg2 16. Lxg2 Kxf8
play all play one stop play next play all
Cook: NL
b) 1. Sb1-c3 b7-b5 2. Sc3xb5 c7-c6 3. Sb5xa7 Dd8-c7 4. Sa7xc8 Ta8xa2 5. Sc8xe7 Ta2xa1 6. Se7xc6 Ta1xc1 7. Sc6xb8 Tc1xc2 8. Sb8xd7 Dc7xh2 9. Sd7xf8 Dh2xg1 10. Th1xh7 Tc2xb2 11. Th7xh8 Tb2xd2 12. Th8xg8 Td2xd1+ 13. Ke1xd1 Dg1xf2 14. Tg8xg7 Df2xg2 15. Tg7xf7 Ke8xf7 16. Lf1xg2 Kf7xf8 (Mario Richter)
paul: a) is Jacobi+ (2019-2-23)
more ...
comment
Keywords: Unique Proof Game, Massacre PG, Rex solus (s)
Genre: Retro
Reprints: 119 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2017-4-25 more...
6 - P0000307
Thomas Volet
8130 Die Schwalbe 141 06/1993
P0000307
(12+14)
Ist die Stellung legal?
Die kürzeste Zugfolge bis zum letzten B-Zug sieht prinzipiell so aus ('...' = Wartezug):
R: 1. Ta8-b8 Kd1-c1 2. Kb8-c8 Ke2-d1 3. Lf8-g7 Lg7-h6 4. Lg8-h7 ... 5. Tb1-b2 ... 6. Th1-b1 ... 7. Th7-h1 Lh6-g7 8. Tg7-h7 ... 9. Lh7-g8 ... 10. Tg8-g7 ... 11. Lg7-f8 ... 12. Tc8-g8 ... 13. Lg8-h7 Td8-d7 14. Lh7-g8 Tg8-d8 15. Lf8-g7 Tg7-g8 16. Lg8-h7 Th7-g7 17. Te8-c8 Lg7-h6 18. Kc8-b8 Th1-h7 19. Lh7-g8 Lh6-g7 20. Lg7-f8 Tg1-h1 21. Tg8-e8 Tg4-g1 22. Lf8-g7 ... 23. Tg7-g8 24. Lg8-h7 25. Th7-g7 Lg7-h6 26. Th1-h7 Lh6-g7 27. Kd7-c8 ... 28. Lh7-g8 ... 29. Lg7-f8 ... 30. Tg8-a8 ... 31. Lf8-g7 ... 32. Tg7-g8 ... 33. Lg8-h7 ... 34. Th7-g7 Lg7-h6 35. Th3-h7 Th4-g4 36. ... Th7-h4 37. ... Lh6-g7 38. ... Tg7-h7 39. Lh7-g8 Tg8-g7 40. Lg7-f8 Ta8-g8 41. Lf8-g7 Lg7-h6 42. Lg8-h7 ... 43. Th7-h3 Lh6-g7 44. Tg7-h7 Ld3-c2 45. Lh7-g8 ... 46. Tg8-g7 ... 47. Lg7-f8 ... 48. Td8-g8 ... 49. Ke8-d7 ... 50. Kf8-e8 Lb5-d3 51. ... Ld7-b5 52. ... Lc8-d7 53. ... d7-d6!
play all play one stop play next play all
"Nach 'unserer' Ausdrucksweise ist die Stellung also illegal, weil nur unter Außer-acht-Lassung der 50-Züge-Regel erspielbar." (HHS)
"Schöne Rangierarbeit mit guter Ausnutzung der LL-Schleuse" (DB).
Auf derartige Forderungsfragen erwartet man ja i.a. ein JA als Antwort und so wäre eine Verkürzung der Zügezahl auf genau 50 Züge bis zum letzten B-Zug angebracht (und auch leicht zu bewerkstelligen). So vermutet jeder einen besonderen - aber nicht vorhandenen - Trick des Autors, um die 50-Züge-Beschränkung nicht zu überschreiten. Mehrere Löser kamen beim Rangieren offensichtlich so ins Schwitzen, daß sie gar nicht an die 50-Züge-Regel gedacht haben und so fälschlicherweise 'Legalität' behauptet haben! Ebenso falsch lagen einige Löser, die 'Illegalität' attestierten mit der Begründung sSh8 oder sLh6 seien nicht zu realisieren. 3/III und 5L., welche die Stellung aufgedröselt haben (von denen kam nur HHS zu der Erkenntnis: illegal!).
Brassaud: Je suis d’accord avec la solution proposée jusqu’à 53) Wartezug, d7-d6 et la partie est considérée comme nulle.
La position intermédiaire obtenue après 53) … , d7-d6 est la suivante :
T1ft1R1c/pppp/PPFF/4PtPf/3pppp1/8/1P6/P2pr3/7T
Cette position est-elle légale ? Je ne le crois pas. Les pions noirs ont pris 4 fois. Le pion h2 a donc été promu. Cette promotion peut être encore sur l’échiquier sous forme de T ou de F, ou bien a été prise mais c’est sans réelle importance. Pour dénouer cette position il faut d’abord reprendre d6xCe7 puis c5xDd6 afin de ramener ce pion en c2. A ce moment la tour blanche et les 2 fous de cases noires peuvent sortir mais le FB de g8 et le roi blanc sont encore dans la cage. Le pion de c2 a effectué les 2 seules prises de pièces noires. Les autres PB venus de e2,f2, g2 n’ont pas fait de prise et le pion de h2 a été promu en h8 sans prise. Il faut ensuite reprendre d6-d5 et e7xd6 (pièce quelconque)puis reprendre la promotion du pion en h8. Mais là je ne vois pas comment en raison du cavalier bloqué par les 2 pions blancs de f7 et g6. Le retour d’une pièce promue (dame ou tour ou même le fou de g7) en h8 ne peut se faire, donc on ne peut reprendre le retour de h7-h8 puis h6-h7 et h5-6 ni bien entendu reprendre h6xg5 pour tout dénouer.
Ainsi je pense que le problème en lui-même est illégal avant même de faire intervenir la règle des 50 coups. Pouvez-vous me dire si quelque chose m’aurait échappé ? (2015-9-11)
Thierry LE GLEUHER: Sorry but the position is legal. The retro play can continue with d6-d5 and d5xXe6, and unlock the rest is easy. (2015-9-13)
Brassaud: Merci pour votre aide. (2015-9-17)
Thomas Volet: TV: The composition's only point is the extension of the retroplay by the interaction of the 3 Bs.
I do not accept anyone's "codex" that purports to alter the rules of chess by making the draw automatic or that imports castling. Under the chess rules, a draw is at the option of the moving player whenever the sequence of non-P, non-capturing moves is sufficiently long (and has nothing to do with castling).
If interested in positions that involve the 50-move rule, please see P0008399 (75-move sequence with several rook circuits), P1202286 (where the "codex" automatic draw rule presents the situation in which either player on the move can make a move that is simultaneously a draw and a checkmate), or P1331867 (move preceding the sequence must have been a capture of a non-P by a non-P). (2019-1-2)
comment
Keywords: 50 move rule
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2015-9-17 more...
7 - P0000407
Günter Glaß
4360 Die Schwalbe 81 06/1983
5. Lob
P0000407
(7+9)
Weiß nimmt 1 Zug zurück, so daß Weiß und Schwarz #1
Circe
Duplex
w) R: 1. Kh6xBg5[+sBg7], dann Sf7#
bzw. R: 1. Kh6xBg5[+sBg7], dann 1. Lb5#

s) R: 1. ... Kd3xBc4[+wBc2], dann 1. ... Dgd4#
bzw. R: 1. ... Kd3xBc4[+wBc2], dann 1. Dbg2#
play all play one stop play next play all
HBae: R: 1. ... Kh6xBg5[+sBg7], dann 1. Lb5# bzw. 1. Sf7#
R: 1. ... Kd3xBc4[+wBc2], dann 1. Dgd4# bzw. 1. Dbg2# (2019-2-4)
comment
Keywords: Circe, Help retractor
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-4 more...
8 - P0000434
Hans Gruber
4700 Die Schwalbe 86 04/1984
2.-3. Lob e.a.
P0000434
(1+1)
Ergänze einen sS und 2 sBB zu einem IC!
Längstzüger
(+sBf7,sBg6,sSh8)
play all play one stop play next play all
Nicht +sSh1, sBf2, sBg3

Duplicate Diagram: P1187718, P1347424

Henrik Juel: The solution position is illegal, because Sh8-g6 is longer than g7-g6 and h7xg6, so these pawn moves could not happen
The try position is legal with a promoted Sh1 (2019-2-14)
comment
Keywords: Illegal cluster, Maximummer, only Kings
Genre: Retro, Fairies
Reprints: 110 Die Schwalbe 244, p. 582, 08/2010
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-15 more...
9 - P0000549
Hans Gruber
René Jean Millour

3464 Die Schwalbe 68 04/1981
P0000549
(1+1)
Ergänze weiße Steine minimaler Gesamtqualität zu einem IC
Keine Bauern auf der 1./8. Reihe
Mars-Circe
+wBe2,wBg2
play all play one stop play next play all
Die Lösung des ursprünglichen Alleinautors HG (+wBe2 f2 g2) ist nicht die Lösung, da die Stellung nach Entfernen des wBf2 immer noch illegal ist. Die Lösung von RJM, der damit auf Wunsch von HG zum Koautor wurde (+ wBe2 g2), ist aber auch nicht richtig: NL +wB auf 1. oder 8. Reihe. Dies muß also ausgeschlossen werden.
Henrik Juel: With the additional condition ruling out solutions like +wPa1, the problem now seems correct
Adding wPe2,g2 gives an illegal position, as [Lf1] could not have been captured on f1 in Mars Circe (2019-2-14)
more ...
comment
Keywords: Circe (Mars), Illegal cluster, only Kings
Genre: Retro, Fairies
Reprints: G) Problemkiste (50) 08/1987
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-15 more...
10 - P0000726
Hans Gruber
2873 Die Schwalbe 58 08/1979
P0000726
(3+5) C+
ser-h#19
Wieviele Lösungen?
Eine Lösung ist: 1. e5 2. f5 3. f4 4. f3 5. f2 6. f1=L 7. Ld3 8. g5 9. g4 10. g3 11. g2 12. g1=D 13. De3 14. h5 15. h4 16. h3 17. h2 18. h1=D 19. Dhe4 c3#
play all play one stop play next play all
911,797,992 Lösungen
Basically there are 1,6,6,6 moves, and choices of promotion to D/L in 2 cases. The difficulty is in managing the collisions on f2,f3&g2. The best way is probably consider in turn which pawn has priority to pass through the square. This partitions the solution set into 2^3=8 cases.
A.Buchanan: I see that the term "Pawn Endgame" is now the English translation of "Kindergarten Problem". To me, an endgame is a study. Does "Kindergarten Problem" carry that connotation in German, or does it refer more to general compositions such as this one? (2019-2-2)
Mario Richter: The latter is the case, we even have some famous Kindergarten Problems in the Retro genre (think e.g. of some of Thierry LeGleuher's works). "Kindergarten" refers to the fact that besides the two kings only "children" (aka pawns) are on the board.
So I do not understand the choice of "Pawn Endgame" as the english translation, even less because the english language has a word like "kindergarden" ... (2019-2-2)
A.Buchanan: Rainer Staudte has recently changed it. Out of respect, I don't want to unilaterally change it back but would like to hear his perspective. Apparently even in English, Kindergarten is the more common spelling. (2019-2-2)
more ...
comment
Keywords: Path enumeration, Series mover, Promotion in forward play, Kindergarten Problem, Excelsior
Genre: Mathematics, Fairies
Computer test: Mario Richter: rawbats' output: 911797992 Loesungen gefunden time= 1.535000(s) (2019-2-2)
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-3 more...
11 - P0000764
Leonid Makaronez
1160 Die Schwalbe 24 12/1973
P0000764
(9+14)
#2
1. c7! ... 2. c8=D,T#
1. ... 0-0? is illegal!
play all play one stop play next play all
Paulo Roque: Solution:
1. c7 ~ 2. c8=D (or T) # (1. ...0-0 is illegal !)

Demonstration the illegality of the castle:

a) Logical elements in the diagram (LED):
(a.1) The bishops black and white were captured in original squares.
(a.2) sLa7 is pawn-promoted, note square f8. The promotion was in square g1.
(a.3) captured two black pieces (vide a.1, then two bishops ).
(a.4) captured seven white pieces (two rooks,one knight, two bishops, queen and one unknown).
The piece unknown: (uk1) is one pawn, or (uk2) is one pawn-promoted, or (uk3) is one piece original equal the pawn-promoted which is in the diagram.

b) Development:
(b.1) The white pieces were captured in: The pawn-h black was promotion in square g1, is necessary hxgxh2xg1 (three captures) + two bishops white captured in original squares xLc1 xLf1 (two captures) + c7xd6(one capture) + a7xb6(one capture) = seven captures pieces white.
(b.2) The structure in the diagram with sLa7,sBb7,sBb6,sBd7,sBd6 is only possible if the promotion of pawn-h black and -c7xd6- preceding -a7xb6-.
(b.3) Then pawn-a white was promotion in square a8 and the piece unknow (a.4) is uk3, only possibility a8=S.
(b.4) On the way Sa8 for e5, necessarily have to go in square c7,then impossible s0-0.

c) Conclusion: 1. ...0-0 is illegal.

Keywords: Cant Castler (2009-7-17)
Henrik Juel: The illegality of castling may also be shown by looking at the retroplay. La7 is [Ph7] promoted on g1, so all missing white men are accounted for, and [Pa2] must have promoted on a8. We cannot uncapture a white officer fast, so the retroplay must start by unpromoting Se5. But it needs to pass c7, so black king has moved. (2009-8-21)
Paulo Roque: Henrik, your solution is very elegant! (2009-8-21)
Yoav Ben-Zvi: As noted by Henrik above, proof that Black "Cant Castle" is based on showing that the White piece unpromoted on a8 is wNe5 rather than an officer uncaptured by one of the bPs. This is not affected by time pressure. Instead, note that retraction of bPc7xf6 must be preceded by exit of bBa7 from the North-West (via c7) which requires previous retraction of bPa7xb6 which implies previous unpromotion on a8 with the unpromoted wP retreating past a7 to allow its occupation by bP. This shows the unpromotion on a8 occurs before Black can uncapture on b6 or on d6 or by bP unpromoted on g1. It follows that the piece unpromoted on a8 must be wNe5. (2018-12-26)
Yoav Ben-Zvi: Typo bPc7xd6 (not xf6) (2018-12-26)
comment
Keywords: Castling (sk), Cant Castler
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-27 more...
12 - P0001343
Friedrich Amelung
Düna-Zeitung 1897
P0001343
(5+3) C+
#2
1. hxg6ep Kh5 2. Txh7#
play all play one stop play next play all
siehe P1291160
Sally: Der en passant-Schlag als einziger Schlüselzug lässt sich im Zweizüger erst mit acht Steinen darstellen. Dies ist die früheste Aufgabe und beste Darstellung, die mit Zweispänner
möglich ist. (2019-1-18)
more ...
comment
Keywords: En passant, En passant as key
Genre: Retro, 2#
Computer test: Popeye 4.61
Reprints: 55B Retrograde Analysis 1915
169 Allgemeine Zeitung Chemnitz 04/12/1927
(VIII) Problem 37-40 09/1956
(1) Problem 103-105 01/1967
215 Europe Echecs 124 04/1969
D12 feenschach 27, p. 27, 04/1975
(2) Mat Plus 12 10-12/2009
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-17 more...
13 - P0001576
Alexander Kislyak
446 Europe Echecs 316 04/1985
T. R. Dawson et W. Hundsdorfer zum Gedenken
P0001576
(13+11)
Konnte die Stellung ohne Schach dem sK erreicht werden?
Henrik Juel: Solution: Yes, the bK may never have been checked. -1.Bc4 b6 -2.Bb5 Bb7 -3.Ba6 Bc8 -4.Bb7 Rh2 -5.Ba8 Rh1 -6.B=a7 Rh2 -7.a6 a7xR -8.Rb3 Rh1 -9.Rg3 Bb7 -10.Bh2 Rb1 -11.Bg1 Rb3 -12.Re3 Bc8 -13.Re1 Rg3 -14.Bh2 Bb7 -15.Rh1 Bc8 -16.Bg1 Rb3 -17.Rh2 Rb8 -18.Rh1 b7xB -19.Bb5 Ra8 -20.Bf1 Rb8 -21.e2 Ke4 etc. Two screens on g3 help replacing bR by wR in the SE corner. (2003-5-15)
hans: NO,you can't retrack bK without a check. f7-f6 to let bK out makes Bf8 useless! (2010-5-18)
Henrik Juel: I only see your comment now, Hans, and I agree
Early in the game Sd6+ e7xd6 happened (2019-1-7)
Henrik Juel: The real content of this excellent retro is how to resolve the position, but the author chose to frame it with a question that fooled me some 16 years ago
Here is another tricky question he might have asked:
For which black pawn can the exact play not be deduced? (2019-1-8)
Henrik Juel: The black pawns played
a7xTb6-b5, b7xLc6, e7xSd6, and the rest never moved, except for [Pf7], which played f7-f6 or, if [Pb2] had already captured TLS to reach e5, ready for an ep capture, f7-f5 (2019-1-9)
comment
Keywords: Promotion, Volet Pawn
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-8 more...
14 - P0001884
Thomas R. Dawson
Aachener Anzeiger 1926
P0001884
(8+2)
#1 vor 2
VRZ, Typ Hoeg
R: 1. c7-c8=D Lb4xSa3 2. Sc5-a6, dann 1. Sb3#
R: 1. c7-c8=D Lc5xSa3 2. Sb4-a6, dann 1. Sc2#
play all play one stop play next play all
klären: Quelle: Schach ohne Grenzen, S.35, Nr.3 = Magyar Sakkvilag, 1926 (VF)
Henrik Juel: -1.Q=c7 Bb4:S -2.Sc5, 1.Sb3#; -1.. Bc5:S -2.Sb4, 1.4Sc2#. It is illegal to supplement a checking bS on a6. (2003-10-9)
Sally: Weiß nimmt c7-c8D zurück. Nimmt Schwarz Lb4-a3 zurück, so ergänzt Weiß auf a3 einen Springer und nimmt Sc5-a6 zurück, um durch Sb3#. Nimmt Schwarz Lc5-a3 zurück, so ergänzt Weiß auf a3 wieder einen Springer und nimmt Sb4-a6 zurück, um durch Sc2 mattzusetzen. (2012-2-21)
Henrik Juel: Also 'On Retraction Chess Problems' gives Magyar Sakkvilag as original source (2019-2-10)
comment
Keywords: Promotion, Defensive Retractor, Defensive Retractor, Type Høeg
Genre: Retro
Reprints: 127 Magyar Sakkvilag 04/1926
(31) On Retraction Chess Problems 1927
3 Chess unlimited , p. 35, 1969
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-12 more...
15 - P0002213
Anders Olson
Kjell Widlert

7818 Springaren 57 06/1994
P0002213
(2+1)
h-retro-#5
Circe RI
Weiß beginnt
paul: 1. – Ke7xBf8 2.Bg7-f8 Sd6xPf7 3.Bh8-g7 Kd8xRe7 4.Bg7-h8 Kd7xQd8 5.Bf8-g7 Kc6xPd7 & 1.Kxb5(Ke8)#

But cooked:

1. - Ke8-f8 2.Ka4-b5 Sd8-f7 3.Ka3-a4 Sb7xQd8 4.Qd1-d8 Kf8-e8 5.Qh1xQd1 Ke8-f8 & 1.Qb3#

(information obtained from Kjell Widlert) (2018-12-15)
comment
Keywords: Help retractor, Circe, Aristocrat, Rex solus (s)
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-6 more...
16 - P0002289
Andrey Frolkin
Andrej N. Kornilow

2235 diagrammes 92 01-03/1990
P0002289
(14+14)
BP in 21,0
1. f3 Sc6 2. Kf2 Sd4 3. Kg3 Sxe2+ 4. Kg4 Sg3 5. hxg3 Tb8 6. Th5 Ta8 7. Ta5 Tb8 8. Lb5 Ta8 9. c4 Tb8 10. Dc2 Ta8 11. Dg6 Tb8 12. d3 Ta8 13. Ld2 Tb8 14. Le1 Ta8 15. Sd2 Tb8 16. Tc1 Ta8 17. Tc3 Tb8 18. Tca3 Ta8 19. T3a4 Tb8 20. a3 Ta8 21. Lxd7+ Dxd7+
play all play one stop play next play all
Henrik Juel: Natch 3.1 tests the first 20.0 moves OK in 13 seconds, but the first 20.5 moves would take more than an hour, and the entire problem more than a couple of hours, because of the possibility of [Pd7] promoting
So we may never know for sure whether this proof game with 16 oscillations by Ta8 is correct (2018-12-8)
Mario Richter: Henrik, I think certainty about the correctness of this problem can be achieved, if we take into account that Black's last move must have been a capture. (2018-12-10)
A.Buchanan: Henrik: the times you propose for testing don't seem outrageous, even without Mario's sensible heuristic. Also, the last move must have been DxLd7 from one of 5 squares only. (2018-12-12)
more ...
comment
Keywords: Unique Proof Game
Genre: Retro
Reprints: 101 Shortest Proof Games 11/1991
58b 64 Proof Games 2012
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2012-12-26 more...
17 - P0002605
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002605
(7+1)
In welche Richtung ziehen die Bauern?
von oben nach unten
play all play one stop play next play all
Henrik Juel: Last move was g2xDTSh1=L+ (2019-1-1)
comment
Keywords: Promotion
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-26 more...
18 - P0002606
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 13, 1979
P0002606
(7+1)
In welche Richtung ziehen die Bauern?
R: 1. exd6ep+ d7-d5 2. e4-e5+
play all play one stop play next play all
Henrik Juel: The next retraction is also determined
2... Ka7xSa8 (3.Sb6-a8+ or Sb6xDLSa8+) (2019-1-1)
Henrik Juel: oops, that is not true
after 2... Ka7-a8, Lc5 can uncheck directly (2019-1-2)
comment
Keywords: En passant, Rex solus (s)
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
19 - P0002607
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002607
(3+1) C+
Welches war der letzte Zug?
Weiß am Zug
R: 1. Ka7xSa8
play all play one stop play next play all
AB: Anticipated by P0001033. I feel almost guilty pointing this out, because Smullyan did so much to popularize RA. (2001-10-30)
Henrik Juel: The author of P0001033, Jan Mortensen, was no slouch either
For some 40 years he was the driving force in DSK, the danish chess problem society (2019-1-1)
comment
Keywords: Last Move? (KxS), Type B, anticipated (P0001033)
Genre: Retro
Computer test: RSP 1.2
Reprints: Schach mit Sherlock Holmes 1982
(1) diagrammes 86 07-09/1988
Outrageous Chess Problems 2005
R1 Phénix 275-276, p. 10810, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-9 more...
20 - P0002608
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002608
(12+14)
Auf welchem Feld wurde die wD geschlagen?
h6
play all play one stop play next play all
Henrik Juel: The pawn captures are determined, and also their sequence
d7xSe6 first, then a2xLb3, and finally g7xDh6 (2019-1-1)
comment
Keywords: Where was piece x captured?
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-26 more...
21 - P0002609
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002609
(3+1+1)
Welche Farbe hat der Bg3?
Monochromes Schach
sBg3 (Weiß hat rochiert)
play all play one stop play next play all
Henrik Juel: ... and wKb4 got out via h2 and g3 (2019-1-1)
comment
Keywords: Monochrome, Castling (wk)
Genre: Retro, Fairies
Reprints: feenschach 50 04-06/1980
Schach mit Sherlock Holmes 1982
R4 Phénix 275-276, p. 10812, 07-07/2017
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-26 more...
22 - P0002610
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002610
(3+1)
Der wK hat weniger als 14 Züge gemacht. Weise nach, daß eine UW stattgefunden hat!
Monochromes Schach
Der sSb8 kann nur von einem Bauern geschlagen worden sein!
play all play one stop play next play all
Henrik Juel: Strictly speaking, [Sb8] could also have been captured by DTL, e.g. h4xPg5xPf6epxPe7xDd8=DxSb8
But White must have promoted (on a dark square) (2019-1-1)
comment
Keywords: Monochrome, Promotion
Genre: Retro, Fairies
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-26 more...
23 - P0002612
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 30, 1979
P0002612
(11+10)
Welcher Stein steht auf h4?
(+wLh4!)
R: 1. c7xSd8=T,c7xLd8=T+
(sBhxXg2)
play all play one stop play next play all
Auf h4 steht ein wL
Henrik Juel: White captured [Lf8] with an officer, and the remaining four missing black men by fxexdxc and c7xLSd8=T+
So Black captured b7xa6, f7xe6xd5xc4, and h3xg2 on light squares, leaving only the dark-squared [Lc1] to be disclosed on h4 (2019-1-2)
Yoav Ben-Zvi: The detailed solution in Smullyan's book (p29) is reprinted in "Four lives, 2014 Ed. Jason Rosenhouse" (a tribute to Smullyan published shortly before his death). Another version appears in the wonderful chapter by Bernd Gräfrath in "Philosophy looks at chess, 2008 Ed. Ben Hale" where it is stated that Smullyan composed this problem at age 16 and considered it his best Retro problem. The following analysis is adapted from these sources:
Last move was -1.wPc7x(B or N, not Q or R)d8=R. The unpromoted wP implies 3 captures by [wPf2] (not 4 captures by [wPg2] plus 1, on g3, by [wPf2] since [bBf8] was not captured by a wP) implying that wPg3 comes from g2. It also implies promotion of [bPh7] (to bB or bN) after capturing on g2 (behind wPg3), a fifth capture by bP. The piece on h4 could not be bQ or bR (both kings would be in check) or bB or bN (requires a second Black promotion) therefore the piece on h4 must be White. A White piece on h4 other than wB would imply that [wBc1] was captured by a bP but all 5 captures by bPs are on light colored squares so:
Solution - White bishop stands on h4. (2019-1-2)
comment
Keywords: Promotion
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
TLG/4 feenschach 173, p. 303, 07-09/2008
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
24 - P0002614
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 45, 1979
P0002614
(12+11)
Schwarz ist am Zug. Darf er rochieren?
Mario Richter: vgl. mit P1012380 (2010-4-17)
Henrik Juel: Last move was a2-a3, so to prevent white retro-stalemate Black must uncapture a wS at once
Tb8xSa8 or LxSc8 do not give White a previous move, so the uncapture happened on e8 or h8, and Black may not castle (2019-1-2)
comment
Keywords: Castling (wksk), Cant Castler
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
25 - P0002615
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 46, 1979
P0002615
(6+4)
Weder Weiß noch Schwarz haben mit ihrem letzten Zug einen Stein geschlagen. Schwarz ist am Zug. Darf er rochieren?
Henrik Juel: Last move was not white castling, because the no-capture stipulation for Black would imply that the only previous white move available could be e2xf3??, rendering the position illegal (because d2-d1=L would be impossible)
So last move was Kh1-g1 or Kh2-g1, Th8 has moved to check, and Black may not castle (2019-1-2)
comment
Keywords: Castling (wksk)
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
26 - P0002616
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 49, 1979
P0002616
(9+9)
Welcher Stein steht auf a5?
(+wKa5)
play all play one stop play next play all
Alfred Pfeiffer: Auf a5 steht der wK. (2012-1-11)
Henrik Juel: No Mystery here (2019-1-2)
Mario Richter: No mystery, but a little joke ("Sir Reginald's Jest"): the position was given as a trap to Sherlock Holmes, who immediately started analysing: Let's see now; Black is in check. What could have been White's last move? Obviously a rook from b7 capturing a Black piece on a7. I guess the next question now is, what was the Black piece? If it was a rook, then Black has promoted earlier..."
A this point the spectators could resist any longer laughing out loud pointing out that the piece obviously has to be the White King. Holmes concluded: "I have really been given a good dose of my own medicine. How many times have I not told Dr. Watson: 'In looking for the subtle, be careful not to overlook the obvious.'" (2019-1-3)
comment

Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
27 - P0002618
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 53, 1979
P0002618
(8+10)
Weiß setzt in einem Zug matt.
a) Brettdrehung 90° in Uhrzeigerrichtung (a1->a8) 1. f7xe8=D,L#
b) Brettdrehung 90° gegen die Uhrzeigerrichtung (a1->h1) 1. g4#
play all play one stop play next play all
Henrik Juel: In the diagram, light and dark squares should be inverted (e.g., h1 should be dark), implying that the board must be rotated 90 degrees; this inversion is probably impossible to achieve in the PDB, otherwise Gerd would have done it
Clockwise rotation: 1.'Pb6xTa5=DL#'
Counter-clockwise: 1.'Pc2-d2#' (2019-1-2)
comment
Keywords: Board Rotation
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
R3 Phénix 275-276, p. 10811, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
28 - P0002620
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 56, 1979
P0002620
(13+13)
Keine der Damen hat jemals ihre Felderfarbe gewchselt.
Welche Rochaden sind zulässig?
b) ohne wTg1
c) wTg1->h1
Henrik Juel: An important condition is missing:
The queens never changed square color
With this condition added, we can analyze
White captured all missing black men with exfxgxh
Black captured [Lc1] on c1 and [Dd1] on a light square, so he captured another original white officer with a7xb6, after which White promoted [Pa2] on a8, so Ta8 has moved and Black may not castle
The promoted officer must be Ta1 or Tg1, so White may not castle either (2019-1-2)
Mario Richter: Originalforderung:
It is given that neither queen has ever moved off her own color
a) Which side, if either, can castle?
b) If the rook on g1 is removed, would that affect the answer?
c) If the rook is replaced on h1, then what would the answer be?" (2019-1-3)
Henrik Juel: Thanks for the update, Mario
b)
No need for promotion, as Black could have captured the missing T by a7xTb6
Black may castle, White may not
c)
Like a), but if the promoted officer is Ta1
White may castle short, Black may not castle (2019-1-3)
comment
Keywords: Castling (wgsg)
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
29 - P0002621
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 58, 1979
P0002621
(12+14)
Weiß hat die wD vorgegeben und die beiden wSS sind Originalspringer. Welche Rochaden sind zulässig?
Henrik Juel: With g7xh6 Black did not capture [Lc1], nor [Dd1], nor [Lf1], so [Pe2] must have promoted
If g7xh6 captured the promoted man, the promotion needed two white pawn captures, exPf and either f7xe8 or f7xg8, so Black must have played b3xa2-a1=Y, and White may not castle long
If g7xh6 captured an original man, this was also not [Sb1,Sg1], so [Th1] must have moved, and White may not castle short
White may castle short or long, but we cannot say which (2019-1-2)
comment
Keywords: Castling (wkwg), Odds game
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
30 - P0002625
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 69, 1979
P0002625
(3+2)
Ergänze einen wB auf c4, c5, d4 oder d5, so daß die Partie (mit Schwarz am Zug) nicht remis enden muß!
+wBc4, dann 1. bxc3ep
play all play one stop play next play all
Henrik Juel: tiny typo in stipulation: mit Schwarz, not Scharz
A wP on c4 does not imply that last move was c2-c4, so the ep capture is not legitimized as such; but it is the only way to prevent the game from ending in a draw (2019-1-2)
comment
Keywords: Add pieces, En passant, Kindergarten Problem
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
31 - P0002626
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 73, 1979
P0002626
(8+1)
Darf Weiß rochieren?
Henrik Juel: No, White may not castle right now, because it is Black to move, as he has no last move
Or (if you allow joking) the board is turned upwards down, in which case White could have the move, but castling would still not be possible (2019-1-2)
comment
Keywords: Castling (wkwg), Rex solus (s)
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
R6 Phénix 275-276, p. 10813, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
32 - P0002627
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002627
(5+1)
Weiß am Zug. Ist die Stellung legal?
R: 1. Kc6-b6 oder 1. Ka6-b6
play all play one stop play next play all
Henrik Juel: Yes, the position is legal, as the retroplay could be -1... Kc6-b6 -2.b7-b8=S++ etc. (or Ka6-b6 -2.a7xb8=S++) (2019-1-2)
comment
Keywords: Last Move?, Promotion
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-28 more...
33 - P0002630
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002630
(15+15)
Welche Farbe ist Schwarz, welche Weiß?
Schwarz ist Weiß, Weiß ist Schwarz
play all play one stop play next play all
Henrik Juel: The number of white moves in the game is uneven, and the number of black moves is even, implying that White just moved (assuming that White started; this is the standard parity argument); but this contradicts that Black just checked on c3
If Black started the game, there is no contradiction (2019-1-2)
comment
Keywords: Parity Argument
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-28 more...
34 - P0002631
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002631
(6+9)
Schwarz am Zug darf rochieren. Ergänze einen wB auf f2 oder g2!
+wBf2
play all play one stop play next play all
Henrik Juel: The diagram white pawns captured 6 times, and black pawns 8 times, so after adding a white pawn there is room for just one more capture by each side
Only addition on f2 permits a legal position, where the remaining captures were black hxPg (with promotion on g1) and white h7xg8=DLS (2019-1-2)
comment
Keywords: Add pieces, Castling (sk)
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-28 more...
35 - P0002632
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002632
(14+15)
1. Weiß hat einen Turm vorgegeben,
2. die wSS haben noch nicht gezogen,
3. es fanden keine UW statt,
4. der letzte Zug von Weiß war e2-e4.Darf Schwarz rochieren?
Henrik Juel: Yes, Black may castle, as he had no time to move his king or rooks during the 6.0 moves game (but it is White to move)
Proof game (the black moves could be shifted):
1.a3 Sc6 2.a4 Sh6 3.a5 e5 4.a6 Dg5 5.axb7 Lb4 6.e4 Lxb7
Too many conditions for my taste in this problem (2019-1-2)
comment
Keywords: Conditional problem, Odds game
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-28 more...
36 - P0002633
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 93, 1979
P0002633
(13+15)
Die KK haben noch nicht gezogen. Ergänze einen wB!
Henrik Juel: White captured g2xTh3, so to get [Ta8] out, Black cross-captured b7xTc6 and c7xLb6
The sequence was: [Ta1] to c6 before b7xc6 before g2xh3 before [Th1] to a1
Add wPc4 to permit the wT moves (2019-1-3)
more ...
comment
Keywords: Add pieces, Conditional problem
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
37 - P0002634
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 95, 1979
P0002634
(15+14)
Schwarz ist am Zug. Weiß hat zuletzt mit dem Bf4 gezogen; woher kam dieser Bauer? Es befindet sich keine UWF auf dem Brett,
Henrik Juel: with wPe4 moved to f4:
White captured [Lc8] on a light square with an officer and d2xc3, so Black captured the light-squared [Lf1] either by dxLc or by d3xLe2 (and promotion on e1)
In both cases the sequence must be
e2-e3 (to release [Lf1]) before dxL before d2xc3 before [Lc1] could reach g5 traversing f2
So last move was f3-f4 (2019-1-3)
more ...
comment
Keywords: Conditional problem
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
38 - P0002637
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002637
(15+14)
Befinden sich UWF auf dem Brett?
Yoav Ben-Zvi: The Black piece captured on c3 could not be [bBc8] (captured on a light square) or [bPh7]. Therefore [bPh7] promoted on g1 after capturing [wBc1] (on g3) which was released previously by wPb2xc3. This implies that the piece promoted on g1 could not have been captured on c3 as the capture on c3, releasing [wBc1], occurred before the Black could promote. Therefore the promoted Black piece must be present on the board, replacing the piece captured on c3. The idea is developed further in P0002638. (2018-12-29)
comment
Keywords: Promotion
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-28 more...
39 - P0002638
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002638
(14+14)
Weiß hat gerade rochiert. Befindet sich UWF auf dem Brett?
Yoav Ben-Zvi: The Black piece that accounts for the capture on a3 could not be [bBc8] (captured on a light square) so it was a missing bP that promoted. The bP promotion could not have occurred on h1 ([wRh1] did not move before castling) so the promotion was on g1 or f1. wPg3 came from g2, it could not capture on g3 as this would be the second capture by White on a dark square and Black's 2 missing pieces include [bBc8] which was captured on a light square. This means that the promoting pawn could not have been [bPg7] as this would require 2 captures on the way to promotion (to bypass [wPg2]) plus a third capture by bPh7xg6. Therefore the promoted bP comes from h7 and, to reach the promotion square, it must have captured on column g behind wPg3. If the piece captured on a3 was an "original" (not promoted) Black piece (could be any officer other than [bBc8]) then the piece promoted by Black is present in the diagram, replacing the piece captured on a3. Henceforth we consider the alternative: that the piece captured on a3 was the promoted piece itself. This implies that the capture by the bP on its way to promotion came before the capture on a3. If wBg5 is not promoted then, prior to wPb2xa3, the wB was locked at c1 which implies that [wRa1] had not yet escaped its home corner and that [wBc1] subsequently moved to g5 via b2 crossing c3. This means the White pawn was still standing on c2 and therefore, since the wK had not moved, that the wQ could not have escaped from d1. It follows (for the case of Black promotee being captured on a3) that the White piece captured by the Black pawn on its way to promotion could not have been [wBc1] or [wRa1] or [wQd1] as it has been shown that, in this case, all 3 were locked when this capture occurred. The White piece captured by promoting bP also could not have been a wP since, as noted above, wPg3 came from g2 and the capture occurred behind it. Since the White piece captured on column g could not have been one of the missing original pieces, [wPh2] must have promoted. On its way to promotion [wPh2] could not capture on g7 (with bP waiting on h7) for the same reason as given above for the capture on g3 (not all White captures were on dark squares). Therefore wP must wait on h2 until its way to promotion is cleared by bPh3xg2 so it can subsequently promote on h8 to replace the captured piece (known to be a knight). In conclusion: for every alternative scenario there is a promoted piece on the board.
The stipulation, which might be defined more accurately as "Must there be a promoted piece on the board?", weaves together the alternative strands of the solution.
The presentation of the problem begins on page 106 of the book (chapter "Shades of the Past") relaying the condition that the last move was -1.0-0 and that Sherlock Holme's nemesis, Professor Moriarty, solved the problem in less than 4 minutes while Holmes admits it took him more than 20 minutes. The description of the solution begins on page 155. (2018-12-29)
Mario Richter: @Yoav: Quote: "... to replace the captured piece (known to be a knight)." This is not completely correct.
Just a small thought to think about: Let's assume that Black answers White's castling by playing 1. ... 0-0! In what way does this change the RA? (2018-12-29)
Yoav Ben-Zvi: The conclusion that the piece captured on g2 was a wN is reached under the assumptions that Black's promoted piece was captured on a3 (therefore it is not present in the diagram) and that wBg5 is not promoted (implying that [wBc1] exited after the capture on a3 and before [wQd1] could be released by wPc2-c3). It has been shown that, under these assumptions, [wBc1], [wRa1] and [wQd1] could not have escaped in time to be captured on g2. The piece captured on g2 also could not be a wP ([wPg2] moves to g3) or a wB (wBg4 could not be promoted on the dark square h8) or a promoted piece (the path to promotion of [wPh2] is open only after the capture on g2) so I think the conclusion that it had to be a knight is justified, under the assumptions (although it is not needed to meet the stipulation).
The suggested addition of the condition: "Black retains the right to castle 0-0" prevents any resolution that has [wPh2] promoting on h8. It has been shown above that capture of Black's promoted piece on a3 requires the White promotion on h8 (either to a wB that replaces the one captured on c1 or to a wN that replaces the one captured on g2). This contradiction (promotion on h8 is required but not allowed) means that the piece captured on a3 could not have been Black's promoted piece so it was an original (not promoted) piece. The piece captured on a3 could not be [bBc8] (captured on a light colored square) or a bP so it is a bQ or bR or bB or bN that is replaced in the diagram by the promoted piece, proving that there must be a Black promoted piece present in the diagram position. A fine idea that improves the accuracy of the resolution. (2018-12-30)
comment
Keywords: Promotion, Castling (wksk), Conditional problem
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-2-28 more...
40 - P0002639
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 113, 1979
P0002639
(11+11)
Weiß setzt matt. In wieviel Zügen?
1. axb6ep#!
play all play one stop play next play all
Henrik Juel: White pawns captured bxa, cxb, f6xe7 (to promote on e8), and g2xh3 (the remaining missing black man was captured by an officer)
Black captured h7xg6xf5xe4xd3 and dark-squared [Lc1] with an officer
Last move was not a6xb5, c4xd3, d4-d3, d7xe6, nor d7-d5, e7-e6 (as White moved f6xe7-e8=L and promoted L to c6 or c8), so last move was b7-b5
White mates by axb6ep# (2019-1-3)
comment
Keywords: En passant
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
41 - P0002640
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 115, 1979
P0002640
(12+11)
Der weiße König ist unsichtbar.
Schwarz am Zug setzt matt!
Henrik Juel: The stipulation might be written more clearly:
Black to move mates in 1
In the Reprints it looks strange that the problem appeared as number R8 in Phenix twice on pages 10810 and 10814 (2019-1-3)
Henrik Juel: White captured [Lf8] on f8, cxd, f2xg3, g2xh3, and once more
Black captured b7xTa6, f7/h7xTg6, and [Lc1] on a dark square
With Black to move, wK could not stand in check on e4, f3, nor g2, so Kc6 stands in check from wLh1, and wK must be ready to uncheck (possibly following the retroplay -1.c5xPd5ep+ d7-d5)
The discovered check by wK could not be from e4 (Lxd3+ is impossible) or f3 (impossible double check), so it was from g2, and wK must stand on g1
Black mates with Sf3#
(On g2 wK would stand in double check explained by f2xLe1=S++, so Black earlier captured h7xTg6, not f7xTg6) (2019-1-3)
comment

Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
R8 Phénix 275-276, p. 10810, 07-08/2017
R8 Phénix 275-276, p. 10814, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
42 - P0002641
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 118, 1979
P0002641
(15+15)
Beide Seiten dürfen rochieren.
Ergänze einen wL auf a3 oder a4!
(+wLa3)
R: ?
play all play one stop play next play all
Mu-Tsun Tsai: Actually to solve this problem there's no need to know if Black can castle. When it comes to the part of explaining why the Pawn originated in e2 can't promoted, it suffice to notice that it can only go straight forward and therefore cannot pass the Pawn originated in e7. (2009-5-12)
Henrik Juel: White's only capture was a2xb3, so Black must have captured [Pe2] with an officer and played e2xLd1=LS or e2xLf1=LS
Add the dark-squared wL on a3 (2019-1-3)
Yoav Ben-Zvi: Smullyan thought that if bK could vacate e8 then [wPe2] could promote there. However, as shown in the solution on page 158, with wK immobile the promotion of [bPe7] occurs from e2 not from d2 and, since Black does not have the captures needed to promote from e2 after clearing the way on the e file, [wPe2] is prevented from moving straight forward to promotion. Therefore (as noted by Mu-Tsun) White retaining castling rights is a sufficient condition . In addition to removing the condition on Black castling, I think wPd5 can be removed ([bPe7] could then capture the wP and arrive at e2 but it needs a further capture to promote). Another idea, closer to Smullyan's intention, is to remove bQd7 and retain the condition on Black castling (preventing wP promotion from d7). (2019-1-5)
A.Buchanan: White is marked as having 15 units - which means that both of the x marks are being counted as White! I am not sure I can edit these in any case. But conventionally the x+y indicates the number of pieces visible in the diagram, for checking purposes, and does not include units to be added. It hardly matters, but it interests me. It would be possible to replace the x marks with lines, which are definitely available for users to edit. (2019-1-5)
A.Buchanan: Curious that the x marks are coded as *Black*: sXa3a4, yet are counted as White. Also, even after units are added to positions, the counter (y+z) is never updated. (Here hit the "play" button above. The "?" after the R: is necessary to get the position to update.) (2019-1-5)
comment
Keywords: Add pieces
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2019-1-5 more...
43 - P0002642
Raymond Smullyan
v The Chess Mysteries of Sherlock Holmes , p. 120, 1979
P0002642
(6+4)
Zeige, daß eine UW und ein ep-Schlag stattgefunden haben!
Weiß am Zug
Monochromes Schach
Cooker: Illegal position. I don't see what black unit takes the white bishop f1. (2002-9-21)
Joost de Heer: In the second (or perhaps even later?) version of this book, a white bishop is added on f1.
See http://janko.at/Retros/Misc/SmullyanErrata.htm for a list of errata in 'Sherlock Holmes'. (2002-9-27)
Henrik Juel: Black has castled and his king exited via h7 and g6, so last move was done by Ka2
The only possibility is Kb3xTa2, preceded by Tc2-a2+
The uncaptured wT is a pawn promoted after four captures; three of these captured [Ta8,Lc8,Pb7], and as [Sg8] never moved, the remaining capture was en passant, e.g.
a2-a4xPb5xPa6epxLb7xTa8=T (2019-1-3)
comment
Keywords: Monochrome, En passant, Promotion
Genre: Retro, Fairies
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
44 - P0002643
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 123, 1979
P0002643
(6+4)
Monochromes Schach?
Henrik Juel: Suppose the monochrome condition is in effect
Then everything is honky-dory except for Da6, which is [Pd7 ] or [Ph7] promoted on f1 or h1, e.g., h7-h5xYg4xPh3epxDg2xLf1=D
Here Y is [Pa2] promoted to DTL on c8 or e8; this seems possible, as [Ta8,Lc8,Pd7] and an ep-capture are available, but it does not work, since [Ta8] cannot reach b5: a2-a4xZb5xPc6epxPd7xLc8??, and a2xVb3xWc4xPd5xPc6epxLd7xTc8?? is even worse
So the monochrome condition is not in effect (2019-1-3)
comment
Keywords: Monochrome
Genre: Retro, Fairies
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
45 - P0002645
Raymond Smullyan
M2 The Chess Mysteries of Sherlock Holmes , p. 146, 1979
P0002645
(3+2)
In den letzten 5 Zügen haben weder der wK noch die Dame einen Zug ausgeführt. Auch sind keine Steine geschlagen worden. Was war der letzte Zug?
R: 1. Lg5-h6 a5-a4 2. Ld8-g5 a6-a5 3. d7-d8=L a7-a6 4. d6-d7 Kg8-h8 5. d5-d6+
play all play one stop play next play all
Henrik Juel: With the stringent conditions the only possibility is to unpromote Lh6 and let the resulting pawn uncheck, when Black must retract Kg8-h8
Unpromotion on b8 is too slow
Last move was Lg5-h6 (2019-1-3)
Mario Richter: Originalforderung: "Neither the White king nor queen has moved during the last five moves, nor has any piece been captured during that time. What was the last move?"
Ich schlage vor, das "Figuren" in der deutschen Version der Forderung durch "Steine" zu ersetzen, weil "Figuren" im Deutschen die Bauern nicht mit einschließt, was aber hier offensichtlich bezweckt zwar. (2019-1-4)
comment
Keywords: Last Move?
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
46 - P0002646
Raymond Smullyan
M3 The Chess Mysteries of Sherlock Holmes , p. 146, 1979
P0002646
(3+8)
In den letzten 5 Zügen hat kein Bauer gezogen, und es wurden auch keine Figuren geschlagen. Versehentlich fiel der sK zu Boden. Auf welchem Feld muß er stehen?
(+sKc8)
R: 1. ... Td8-h8 2. Kg8-f7 0-0-0 3. Kh8-g8 Sc1-a2,S~ 4. Kg8-h8 Sa2-c1,5. Kh8-g8 Sc1-a2,S~ 6. Kg8-h8
play all play one stop play next play all
Henrik Juel: The only way to avoid retrostalemate under the conditions is to put sK on c8 and retract
-1... Td8 -2.Kg8 0-0-0 -3.Kh8 S~ 4.Kg8 S~ -5.Kh8 S~ -6.Kg8 (2019-1-4)
comment
Keywords: Add pieces, Castling in the retro play
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
47 - P0002648
Raymond Smullyan
M5 The Chess Mysteries of Sherlock Holmes , p. 147, 1979
P0002648
(14+14)
Keiner der beiden KK hat bisher gezogen.
a) Weisen Sie nach, daß einer der 4 Springer schon einmal gezogen hat, wenn sich auf dem Brett keine weißen UWF befinden.
b) Weisen Sie nach, daß zwei der SS schon einmal gezogen haben, wenn sich auf dem Brett keine schwarzen UWF befinden.
Henrik Juel: I believe the stipulation is incorrect.
If there are no promoted men on the board:
Black played g3xLh2-h1=Y (DS), so Sg1 has moved
White played dxPc-c7xYb8=S-a6 (or =D), so Sb8 has also moved
If there are no white promoted men on the board:
White captured [Lc8] on c8 with Dd1 and promoted to DTS on c8, later captured on a6
Black promoted to L on h1, so Sg1 has moved; this L is now on a4 (2019-1-4)
comment

Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
48 - P0002649
Raymond Smullyan
M6 The Chess Mysteries of Sherlock Holmes , p. 148, 1979
P0002649
(14+15)
Weiß darf rochieren. Ist die wDd2 die Originaldame?
Henrik Juel: The missing men are a black T, the white pawn from a2 or c2, and the white L from f1
Black crosscaptured to let a T out to b3 ([Lf1] was captured on the light square) and allow a white promotion to replace the captured original officer (capturing a white pawn on the dark square does not work)
The details are:
1. a7xDb6
2. sT gets out to be captured by c2xTb3, and Pa2-a8=D
3. b7xLa6
Promotion to T would not work, because Ta1 is immobile and Tg1 is inaccessible by the castling condition; a light-squared L is not on the board now; an S could not leave a8
Crosscapture on d6,e6 (or a2xTb3) would not permit promotion
Dd2 is promoted (2019-1-4)
comment

Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
49 - P0002650
Raymond Smullyan
M7 The Chess Mysteries of Sherlock Holmes , p. 148, 1979
P0002650
(16+12)
Beide Seiten dürfen noch rochieren. Auf c6 steht eine unbekannte schwarze Figur, aber kein Turm.
a) Angenommen, es ist ein Springer, auf welchem Feld ist dann die fehlende schwarze Dame geschlagen worden?
b) Angenommen, es ist die Originaldame, auf welchem Feld ist dann der fehlende sS geschlagen worden?
c) Angenommen, es ist eine umgewandelte Dame, wo ist dann der schwarze Springer geschlagen worden?
Henrik Juel: The missing [Ta8] was captured in its corner
White captured the other two missing black men with b2xc3 and g2xh3
The only black capture was c7xDb6, so [Pg7] must have promoted to D, T, or L on g1 after g2xh3 (promotion to S is ruled out, because Sg1-f3 would ruin white castling)
b2xc3 (letting [Dd1] out) happened before c7xDb6, which lets [Dd8] out
Here follow the pawn captures and the promotion, and their sequence, for the three situations; this is easily found by considering the few possibilities
A. Black S on c6
1. b2xLc3
2. c7xDb6
3. g2xDh3
4. g1=L, now on g7
The D was captured on h3
B. [Dd8] on c6
1. g2xSh3
2. g1=Y
3. b2xYc3
4. c7xDb6
The S was captured on h3
C. Promoted [Pg7] on c6
1. b2xSc3
2. c7xDb6
3. g2xDh3
4. g1=D, now on c6
The S was captured on c3 (2019-1-4)
comment

Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
50 - P0002651
Raymond Smullyan
M8 The Chess Mysteries of Sherlock Holmes , p. 149, 1979
P0002651
(15+14)
Schwarz hat im ersten Zug Bd7-d5 gezogen. Der auf f5 stehende Springer hat genau dreimal gezogen. sD, sK und sTh8 haben noch nicht gezogen.
Teil I
A) Weisen Sie nach, daß drei Figuren, die jetzt noch auf ihrem Ausgangsfeld stehen, schon einmal gezogen haben.
B) Hat der Bauer h5 ein- oder zweimal gezogen?
C) Stünde der h-Bauer statt auf h5 auf h6, wäre die Stellung dann noch legal?
Teil II
Angenommen, man entfernt den sLc8 und stellt folgende Bedingungen: Der Läufer soll auf irgendeinem anderen Feld stehen. Er darf aber noch nie auf f7 gestanden haben, er darf auch nicht b7 oder c6 überquert haben, und er darf nicht vor dem weißen Läufer g4 gezogen haben. Auf welchem Feld muß der Läufer dann stehen?
Henrik Juel: The first condition could be formulated more clearly:
Black's first move in the game was 1... d7-d5 (2019-1-4)
Henrik Juel: I
Black has moved Sb8-c6-d4-f5
White captured [Lf8] on f8 with an S
The sequence was something like
d2-d3 and d7-d5, c7xLd6, b7-b6 and Sb8-c6-d4-f5, e2xTf3
Now the route by [Lf1] can be determined:
Lf1-e2-d1-b3-c4-a6-c8-e6-g8-h7-g6 (with [Sg8] screening on f7) -h5-g4
A. Dd1, Lc8, and Sg8 must have moved
B. [Ph7] went h7-h6-h5
C. With Ph5 on h6, the position would be illegal, because Sg8 could not get home
II
With the additional conditions Lc8 would have to run ahead of [Lf1] and now stand on h3 (2019-1-4)
comment

Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-6 more...
51 - P0002652
Raymond Smullyan
M9 The Chess Mysteries of Sherlock Holmes , p. 149, 1979
P0002652
(13+14+1)
Keiner der beiden Könige hat bisher gezogen. Auf f2 steht ein schwarzer oder ein weißer Bauer. Ein weißer Springer steht entweder auf f3 oder f4.
A. Welche Farbe hat der Bauer auf f2?
B. Steht der weiße Springer auf f3 oder f4?
Henrik Juel: La5 must be a pawn promoted on g1
A.
If Pf2 were white, [Ph7] must have promoted on g1, as [Pf7] would need too many captures
Black could play h7xLg6xPh5-h2xLg1=L, but then a7xb6 could not happen (promoting [Ph2] on h8 makes no difference)
Or Black could capture [Ph2] and play h7-h2xLg1, but this would leave no dark-squared white men for a7xb6; if Black played h3xLg2-g1=L (after g2-g3), the L could not reach a5
So Pf2 is black, and it just checked by f3-f2+, because e3xf2+ would require too many black captures, as [Pf2] or [Ph2] was not captured by a black pawn
B.
wS is on f4, since Black just left f3 (2019-1-4)
comment
Keywords: Promoted material on the board (sLa5)
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-6 more...
52 - P0002653
Raymond Smullyan
M10 The Chess Mysteries of Sherlock Holmes , p. 150, 1979
P0002653
(11+10) C+
Weiß ist am Zug. Kann er in zwei Zügen mattsetzen?
1. Dd6 droht 2. Dxe7#
1. ... exd6 2. Sg7#
1. ... exf6 2. Dxf8,Txf8# (Mattdual)
1. ... Kd8 2. Txf8#
1. ... 0-0-0? (illegal!)
play all play one stop play next play all
Henrik Juel: If Black cannot castle, White can mate in 2 moves
1.Dd6 thr. 2.Dxe7#
1... exd6/exf6/Kd8 2.Sg7/DTxf8/Txf8
C+ by Popeye 4.61, except for the dual (2019-1-5)
Henrik Juel: Let us show that Black may not castle (with White to move)
White captured [Lc8] and four of the five remaining missing black men with his pawns on the king-side
Black Pg2 captured four of the five missing white men, which include [Pa2,Pb2], so one of these must have promoted
h7xg6 is illegal as last move (requiring six black captures), and so is h3xg2 (illegal black pawn position)
If Black made last move with Ta8 or Ke8, he may obviously not castle
1. Suppose last move was Dg7-f8
Then White must retract Th8xYf8+, exhausting the five possible captures by White, so White could not promote [Pb2] as this would require another capture; instead he promoted [Pa2] on a8 to supply four capturable white men, meaning that Ta8 has moved, so Black may not castle
If last move was g7-g6 (so [Lf8] was not captured by a pawn), the same analysis applies
2. Suppose last move was Dg7xYf8
This leaves just the needed four white men captured by Pg2, so White must have captured the last available black man with [Pb2] to promote it, and hence promoted [Pa2] on a8, so Black may not castle
If last move was g3-g2 (so Pg2 did not capture the missing light-squared [Lf1]), the same analysis applies
Conclusion: Black may not castle, because he has moved his K or T (2019-1-5)
Yoav Ben-Zvi: The convoluted stipulation is not needed as this is a standard #2 with solution supported by "Cant Castle" retroanalysis. (2019-1-7)
comment
Keywords: Castling (sg)
Genre: Retro
Computer test: Popeye 4.61
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-6 more...
53 - P0002654
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 122, 1979
P0002654
(5+4)
Monochromes Schach
Der wK hat erst zweimal gezogen.
War das Feld h8 mehr als einmal besetzt?
R: 1. g3xTh4 Th8-h4 2. Kf2-e3 Kh7xDg8 3. Dg4-g8+ Tf8-h8 4. h2xLg3 Lh4xTg3 5. Ke1-f2 Kg8-h7 6. Dd1-g4 0-0
play all play one stop play next play all
Henrik Juel: Black has castled, so [Th8] has visited f8.
Where was it captured? Not on f8 or d8, because by the condition wK could not go that far, [Ta1] could not reach row 8, [Lc1] never moved, and White did not promote a dark-squared pawn
So after the castling [Th8] must have moved back to h8
The retroplay could start like this:
-1.g3xTh4 Th8 -2.Kf2 Kh7xDg8 -3.Dg4 Tf8 -4.h2xLg3 Lh4xTg3 -5.Ke1 Kg8 6.Dd1 0-0 (2019-1-5)
Henrik Juel: should be -6.Dd1, of course (2019-1-5)
comment
Keywords: Monochrome, Castling
Genre: Retro, Fairies
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-6 more...
54 - P0002661
Henry Tanner
5094 Thema Danicum 07/1991
P0002661
(1+1)
Ergänze sT, sL und sS zu einem IC!
3 Lösungen
a) +sTb4+sLc4+sSb3
b) +sTc2+sLb3+sSc4
c) +sTd1+sLb1+sSc3
play all play one stop play next play all
Henrik Juel: The solutions feature impossible check by T, L, and S (2019-2-14)
comment
Keywords: Illegal cluster, no 8x8 board, Aristocrat
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-18 more...
55 - P0002678
Hans Gruber
18) feenschach 45, p. 37, 01-03/1979
P0002678
(1+1)
Ergänze 1 wB zu einem IC!
Wieviele Lösungen?
Gitterschach
b) +Ohneschlag

a) 20 Lösungen: a1, ..., h1, a8, ..., h8, c2, e2, a6, h6
b) 34 Lösungen: a1, ..., h1, a8, ..., h8, c2, e2, a6, ..., h6, a7, ..., h7
Henrik Juel: In Grid Chess a white pawn cannot reach a6 (nor h6), as a5-a6 and b5xa6 are impossible
With No-capture Chess added as extra condition a white pawn can reach no higher than row 5 (2019-2-14)
more ...
comment
Keywords: Illegal cluster, No-capture chess, Grid Chess, only Kings
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2015-3-20 more...
56 - P0002730
Maryan Kerhuel
991 Phénix 14 09/1991
Michel Caillaud gewidmet
P0002730
(1+3)
Ergänze wD, wL, 3 wBB, sT und 2 sBB zu einem IC!
Patrouilleschach
(+wDb7,wLc6,wBb6d5d7,sTd6,sBb5e7) R: 1. Dc7xb7, aber keine Auflösung
play all play one stop play next play all
Henrik Juel: The stipulation and solution are inconsistent
Assuming that 2 wBB is changed to 2 sBB, I cannot see how the solution position without Td6 could be legal
-1.Dc7xSb7+ Sd6xSb7 is not possible, as sSd6 checks wK (2019-2-14)
comment
Keywords: Illegal cluster, Patrol Chess, Kindergarten Problem, Rex solus (w)
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-15 more...
57 - P0003049
Raymond Smullyan
The Chess Mysteries of the Arabian Knights , p. xii, 1981
P0003049
(14+15)
Ein sL hat einen weißen Stein geschlagen. Welcher sL?

Der sLe5 hat den wL geschlagen.
H.Juel: The capture sequence must have been g7xSh6 before d2xTc3 before Lx[Lc1]
more ...
comment

Genre: Retro
Reprints: Die Schachgeheimnisse des Kalifen , p. 10, 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
58 - P0003050
Raymond Smullyan
The Chess Mysteries of the Arabian Knights , p. xiii, 1981
P0003050
(5+1)
In welche Richtung spielt Weiß?
Im letzten Zug wurde kein Stein geschlagen.
R: 1. Td2-f2 Kf2-f1 2. Be2xXd1=S+
play all play one stop play next play all
Weiß spielt von oben nach unten!
Henrik Juel: The stated retroplay is the only possibility
so White pawns move downwards (2019-1-23)
comment
Keywords: Conditional problem, Aristocrat, Rex solus (s)
Genre: Retro
Reprints: Die Schachgeheimnisse des Kalifen , p. 12, 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
59 - P0003053
Raymond Smullyan
3a The Chess Mysteries of the Arabian Knights 1981
P0003053
(12+11)
Ersetze einen der Steine durch den wK, so daß die Stellung legal ist!
Henrik Juel: Solution
0. Replacing wK on g8, h7, or h8 obviously does not work; neither does a4, a6, a7, b5, b7, b8, c4, c6, d7, f7, or g6, having both kings in check
1. What about replacing the white man on d5, e4, g4, or h5? This gives four missing white men, three of which were captured on light squares by b7xa6 and d7xc6xb5, while the fourth, [Lc1], was captured on a dark one
Hence the retroplay -1.Df8xYg8 Yxg8 does not work, because g8 is light, nor does -1.Df8xSg8 Sf6 -2.Dh6, because Sf6 would check wK (on d5, e4, g4, or h5)
(-1... Kg7 is illegal, and no other black men can retract)
2. Replacing a black man on a5, a8, e7, or e8 does not work, because the three missing white men include the dark-squared [Lc1]
3. This leaves the solution: putting wK on c7; now the black pawn play could have been b7xa6 and c7xb6-b5, so many retroplays are possible (after the uncheck -1.Df8xg8) (2019-1-23)
comment
Keywords: Add pieces
Genre: Retro
Reprints: 3a Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
60 - P0003054
Raymond Smullyan
3b The Chess Mysteries of the Arabian Knights 1981
P0003054
(12+10)
Ersetze einen Stein einer anderen Art als in der vorigen Aufgabe 3a durch den wK, so daß die Stellung legal ist!
Henrik Juel: Replacing Pa7 or Pc7 with wK would work, but this is ruled out by Alfred's stipulation clarification: wK may not take the place of a black pawn
Compared to P0003053, Da8 has been removed, but an extra missing black man makes no difference, so the arguments from there still apply
b7 is no longer attacked by Black, however, so the solution is putting wK on b7 (2019-1-23)
Mario Richter: Imho, Alfred's stipulation doesn't rule out Pa7, it should be: "Ersetze einen Stein einer anderen Art als in der vorangegangenen Aufgabe 3a (P0003053) durch dem wK, so daß die Stellung legal ist". This fits the original intention, where the problem is embedded into a story about Caliph Haroun al Rashid (the wK), who wents out one night masquerading as some other piece (=3a), and then again the next night (=3b), quote: "Only on this second night, he costumed himself differently than he had on the first." (2019-1-24)
Henrik Juel: Thanks for your clarification clarification, Mario
At first I thought that a7 was a cook, but then I interpreted Alfred's stipulation more broadly (2019-1-24)
more ...
comment
Keywords: Add pieces
Genre: Retro
Reprints: 3b Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
61 - P0003055
Raymond Smullyan
4 The Chess Mysteries of the Arabian Knights 1981
P0003055
(11+11)
Schwarz ist am Zug. Welcher Stein steht auf g4?
Darf Schwarz rochieren?

Steinkontrolle wegen des 'x' nicht exakt.
Henrik Juel: Solution
Black captured [Lc1] on c1 and played e7xd6xc5xb4xa3-a2xb1=L, capturing all six missing white men, so [Pf7,g7,h7] never captured, and Yg4 is black
Last move was not Te1-d1, so it was 0-0-0, and Y is not L
To let [Th1] out to be captured, [Pg2,h2] crosscaptured, so Lh2 is [Pg7] promoted on g1, and Y is not P
The forward sequence was: g2xh3 before [Th1] got out before g1=L before h2xg3, so there were not any more black promotions, hence the hidden black man is Sg4, and [Pf7,h7] were captured on their files
The white captures were a2xLb3, g2xPh3, and h2xLg3, leaving only [Pf7] who was captured on f2, f3, .. , or f7
[Pe2] must have promoted, either on e8, or on f8 via f7, so Ke8 has moved, and Black may not castle (2019-1-23)
comment

Genre: Retro
Reprints: 4 Die Schachgeheimnisse des Kalifen 1984
R10 Phénix 275-276, p. 10810, 07-08/2017
R10 Phénix 275-276, p. 10815, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
62 - P0003058
Raymond Smullyan
7 The Chess Mysteries of the Arabian Knights 1981
P0003058
(12+13)
Der schwarze Damenturm ist von einem Bauern geschlagen worden, der weiße Königsläufer wurde vorgegeben, Die beiden wT sind auf der selben Reihe geschlagen worden. Schwarz kann noch rochieren.
Wo wurden die wTT geschlagen?
Henrik Juel: Too many conditions for my taste
Alfred's addition shows that Ke8 (and Th8) never moved
The only white pawn capture was f2xe3, i.e., f2xTe3, so [Pb7,c7] cross-captured to let [Ta8] out
At first, only [Lc1] could get out, so the first black pawn capture was c7xLb6
But [Lc8] was in the way for [Ta8], so it was captured on c8, and La6 is a pawn promoted on f1
g2-g3 happened early to let promoted Lf1 reach a6, so Sf1 is also a promoted pawn
Hence Black captured gxf, and since the white rooks fell on the same row, they were captured on c6 an f6 (2019-1-24)
Henrik Juel: Alfred's addition was
Schwarz kann noch rochieren. (2019-1-24)
more ...
comment
Keywords: Conditional problem, Odds game
Genre: Retro
Reprints: 7 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
63 - P0003059
Raymond Smullyan
8 The Chess Mysteries of the Arabian Knights 1981
P0003059
(13+13+1)
Schwarz hat soeben rochiert und es sind keine weißen Umwandlungsfiguren auf dem Brett.
Ist der Ta5 weiß oder schwarz?

Ta5 is black
Henrik Juel: First some observations
Black has captured b7xa6 and played g3xh2-h1=L (other ways to promote [Pg7] on a light square need to many captures)
Assume that Ta5 is white
Then the black captures were b7xYa6 (Y is [Pe2] promoted) and g3xLh2
La2 cannot be promoted, because White must play b2-b3 before [Lc1] can reach h2 to enable the black promotion
Lb7 also cannot be promoted, because Black must play c7-c6 before [Dd8] can get out to enable [Pe2] to promote on g8
So Ta5 is black
(Then one of the two needed black pawn captures could be b7xTa6 or g3xTh2) (2019-1-25)
Henrik Juel: For a slightly clearer argument, please replace
'Lb7 also cannot be promoted'
with
La2 also cannot be the original [Lc8] (2019-1-25)
Mario Richter: My first attempt was: +wTa5, then R: 1. ... Lc8-b7 2. ~ b7xSa6 3. Sb8-a6 ~ 4. c7xTb8=S ~ 5. d6xDc7 ~ 6. e5xLd6, before I realized that afterwards it is not possible to unpromote sLa2 ... (2019-1-26)
Alfred Pfeiffer: For the sLL both is possible, each of them can be the original or the promoted piece. Beside the above discussed solution White could play first wTa1 to a6. After bxa6 Black could move its Ta8 to a5 and play its Lc8 to a2. Then White plays b2-b3 and the wLc1 to h2. After the promotion of sBg7 at h1 the promoted bishop could move to b7. Then Black moves c7-c6. In this case there is no need to promote the wBe2. It could be captured somewhere, the sDd8 also. (2019-1-26)
more ...
comment
Keywords: Non-standard material (l)
Genre: Retro
Reprints: 8 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
64 - P0003061
Raymond Smullyan
10 The Chess Mysteries of the Arabian Knights 1981
P0003061
(14+13+1)
Kein Bauer hat bisher mehr als einen Stein geschlagen, die Dh5 ist eine Originaldame. Zeige, daß sich die Farbe der Dh5 bestimmen läßt, wenn bekannt ist, ob die fehlende Dame auf ihrer eigenen Linie geschlagen worden ist!
Henrik Juel: .
If [Dd8] was captured by d2xDc3, Dh5 is white
If not, the capture was d2xTSc3, and Black later played exDd-d1=TS, so Dh5 is black (the sequence was d2xc3 before the promotion before Se3-d1 before e2-e3 before [Lf1] could exit)
Thus, Dh5 is black if the missing D was captured on the d-line, and white otherwise (2019-1-24)
more ...
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 10 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
65 - P0003062
Raymond Smullyan
11 The Chess Mysteries of the Arabian Knights 1981
P0003062
(11+10)
Woher kommt der wBg3?
Henrik Juel: The retroplay was not
-1... Kf6 -2.d5xPe5ep e7 -3.d4
because this would require too many black pawn captures (incl. promotion of Ld8)
So it was -1... Kf6xSg6 -2.Se5
If Pg3 came from f2, too many white pawn captures would be required (incl. promotion to S), so Pg3 came from h2 (2019-1-24)
Henrik Juel: for clarity, please replace the last parenthesis by
(because White must promote to S) (2019-1-24)
comment

Genre: Retro
Reprints: 11 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
66 - P0003063
Raymond Smullyan
12 The Chess Mysteries of the Arabian Knights 1981
P0003063
(13+15)
Weiß darf noch rochieren. Hat sich der sBb7 umgewandelt?
Henrik Juel: Black is missing one man ([Pb7]), so the only white capture was b2xc3, and the obvious explanation of the position is that White captured an original black officer, which was later replaced by promotion
Still, suppose Black did not promote
Then he must have captured a white officer with bxc, and White might promote [Ph2] on h8 after h7xg6 (later Black would have to complete the cross-capture with g7xh6)
In his first pawn capture Black must have captured an original white officer, but we can rule out all five possibilities:
Not S, as a promoted S could not leave h8
Not [Lf1], as it could not be replaced by promotion on h8
Not [Lc1], as it could not get out
Not T, as [Ta1] could not get out, and Th1 never moved
Not D, as Black would have to capture [Lc1] to let her out, and a8=L-h4 would require a total of four black captures
So [Pb7] did promote
(The possibility of White capturing the promoted officer after a2-a3 and b3xTa2-a1=Y will not work, as [Lc1] could not leave the SW corner, and b3xSLa2 are ruled out as above, so the promoted [Pb7] is still on the board) (2019-1-26)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 12 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
67 - P0003064
Raymond Smullyan
13 The Chess Mysteries of the Arabian Knights 1981
P0003064
(14+15)
Beide Könige haben nur je einmal gezogen.
Der sBa7 hat sich umgewandelt; in welche Figur?
Henrik Juel: solution: the promoted pawn is Dd7
Both kings have castled
White castled early to let out [Th1], so Black could capture axTb
To avoid a check on b2, Black must capture again bxTa and promote on a1
Let us consider the possible promotions:
S or L could not move without checking
T could not reach d8,e8
So the promotion was to D (2019-1-26)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 13 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
68 - P0003065
Raymond Smullyan
14 The Chess Mysteries of the Arabian Knights 1981
P0003065
(13+14)
Die schwarze Dame wurde auf ihrer eigenen Reihe und der weiße Damenturm auf seiner Linie geschlagen, keiner der beiden Könige hat gezogen, Schwarz darf rochieren. Was geschah mit dem weißen Bauern h2, der sich umgewandelt hat?
Henrik Juel: Too many conditions for my taste
The move sequence must have been
h7xg6 before h6-h7 before g7xh6 before b2xLa3 before b7xTa6 before h7xDg8=D! (with a screen on f8)
(A promoted S would check on f6 and a promoted L or T could not exit)
So the promoted pawn is Dd1
. (2019-1-26)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 14 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
69 - P0003066
Raymond Smullyan
15 The Chess Mysteries of the Arabian Knights 1981
P0003066
(15+13)
Welcher der beiden wL ist der Originalläufer?
Henrik Juel: solution: La2 is original
[Ta8] was captured in its corner, so White could not promote before g7xf6
Hence the sequence must have been
Lf1-a2 before b2-b3 before g7xLf6 before g8=L-g2
. (2019-1-26)
comment
Keywords: Non-standard material (L)
Genre: Retro
Reprints: 15 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-28 more...
70 - P0003067
Raymond Smullyan
16 The Chess Mysteries of the Arabian Knights 1981
P0003067
(14+13)
Der Th8 ist auf auf seinem Ursprungsfeld geschlagen worden, keiner der beiden KK hat gezogen, auf dem Brett befinden sich keine schwarzen Umwandlungsfiguren. Welches ist der weiße Originalläufer?
Henrik Juel: solution: Lb2 is original
Both h-pawns promoted
The sequences must have been
c2-c3 before c7xDd6 before h6xTg7xTh8=L-h2 before g2-g3
and hxTg before h1=Y before b2xYa3
. (2019-1-26)
Henrik Juel: If [Ta8] was captured on a3, [Ph7] need not promote, and White could just capture [Th8,Ph7] with officers
The result is unchanged (2019-1-26)
comment
Keywords: Conditional problem, Non-standard material (L)
Genre: Retro
Reprints: 16 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
71 - P0003068
Raymond Smullyan
17 The Chess Mysteries of the Arabian Knights 1981
P0003068
(4+4)
Was geschah mit dem weißen Königsläufer?
Henrik Juel: solution: [Lf1] was captured on f1
-1... f4xg4ep -2.g2 f5
. (2019-1-26)
comment
Keywords: Non-standard material (L)
Genre: Retro
Reprints: 17 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-28 more...
72 - P0003069
Raymond Smullyan
18 The Chess Mysteries of the Arabian Knights 1981
P0003069
(11+11)
Welcher weiße Stein wurde vorgegeben?
Henrik Juel: solution: [Lc1]
The retroplay was -1.Dd8xYe8 Yxe8 (-1... b7xa6/c6xb5 are illegal as they would prevent wK from reaching c8), so Black has captured the other missing white men on a light square
. (2019-1-27)
comment
Keywords: Odds game
Genre: Retro
Reprints: 18 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-5 more...
73 - P0003070
Raymond Smullyan
18b The Chess Mysteries of the Arabian Knights 1981
P0003070
(11+11)
Es fanden keine Umwandlungen statt.
Welcher weiße Stein wurde vorgegeben?
Henrik Juel: Seems cooked
As in P0003069 the retroplay shows that Black captured on a6,b5,c6,e8
The captured men must be wTTLS, as no wP could reach any of these squares (White also captured Dd8xe8)
But any one of [Pd2,e2,h2] could have been given as odds (one of Pd7,e6 could be [Ph2]) (2019-1-27)
Mario Richter: Smullyan wrongly argues: "... four White pieces must have been captured (one on e8, and three by the pawns on a6 and b5). The pawn from h2 could certainly not have been captured by either of the two Black pawns, nor could it get to e8 without promoting, which we are given it did not. Hence this pawn must have been given as odds."
As Henrik explained, Smullyan overlooked the simple possibility that wPh2 is still on the board (on d7 or e6).
So the problem is indeed cooked. (2019-1-28)
comment
Keywords: Conditional problem, Odds game
Genre: Retro
Reprints: 18b Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-28 more...
74 - P0003072
Raymond Smullyan
20 The Chess Mysteries of the Arabian Knights 1981
P0003072
(14+14)
Es befinden sich keine UWF auf dem Brett.
Zeige, daß der weiße Königsspringer bereits gezogen hat!
Henrik Juel: .
[Pb7] did not promote, because otherwise it would be on the board
The capture sequence must have been bxTa before b2xPa3
So [Sg1] must have moved to let a wT out
. (2019-1-27)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 20 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-28 more...
75 - P0003073
Raymond Smullyan
21 The Chess Mysteries of the Arabian Knights 1981
P0003073
(13+10)
Einer der beiden weißen Springer hat noch nicht gezogen. Welcher?
Henrik Juel: solution: Sg1
The retroplay was -1.Pc5xPd5ep d7 -2.c4 Ke8, so [Lc8] was captured on c8
The other white captures were b2xc3, e2xd3xc4, fxg, while Black played f7xTg6xPh5, axLb-b1=Y, so Sb1 must have moved
(The problem could have formulated without a condition by asking
Which wS must have moved?)
. (2019-1-27)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 21 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-5 more...
76 - P0003074
Raymond Smullyan
22 The Chess Mysteries of the Arabian Knights 1981
P0003074
(5+12+1)
Schwarz ist am Zug. Ist der Sa1 weiß oder schwarz?
Henrik Juel: solution: Sa1 is white
Last move was Kd1xSd2, so the black knights are accounted for
. (2019-1-27)
comment

Genre: Retro
Reprints: 22 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2019-1-28 more...
77 - P0003075
Raymond Smullyan
23 The Chess Mysteries of the Arabian Knights 1981
P0003075
(12+10)
Ein weißer und ein schwarzer Springer haben die Farbe getauscht. Welche Springer?
Henrik Juel: solution: Sa1 and Sa3
White pawns captured all missing black men, so last move was Sc2-a3+, preceded by b2xa1=S
. (2019-1-27)
more ...
comment

Genre: Retro
Reprints: 23 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-28 more...
78 - P0003083
Raymond Smullyan
30 The Chess Mysteries of the Arabian Knights 1981
P0003083
(12+14)
Eine Figur hat die falsche Farbe. Welche?
Henrik Juel: solution: Lf1
The pawns are true by stipulation (Figur means officer) and the kings are obviously true
[Lc1] was captured on c1, so Lh4 is true and checking Ke1
Hence Sf3 and Dd8,Th8,Sc7,Sf6 are true
Ta8 is true, because a wT could not have left row 1
Dc4 is true, because a black promotion would require four captures, but only wDS and one wT are available
So Lf1 is black, explainable by Black capturing [Lf1] and playing c5xTd4xTe3xSf2=L
. (2019-1-27)
comment

Genre: Retro
Reprints: 30 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
79 - P0003084
Raymond Smullyan
31 The Chess Mysteries of the Arabian Knights 1981
P0003084
(13+11)
Weiß ist am Zug, beide KK haben noch nicht gezogen. Zeige, daß der wLg7 bereits die 8. Reihe betreten hat!
Henrik Juel: .
White captured [Ta8,Lc8,Dd8] with an S in the NW corner, g2xTh3, and [Lf8] somewhere
So Pb3,c3 did not cross-capture, [Ta1] was captured in the SW corner, and Pf5 never captured
Sg8 entered via h6, and last move was f6-f5 (not Sc2-a1 or Sd3-c1), allowing these (forward) sequences:
L-g7 before f7-f6
White captured [Lf8] on f8 before Th8-f8 before Sh6-g8 before g7xDh6 before g2xTh3
So [Th8] went Th8-f8-f7-g7-h3, showing that Lg7 visited h8 or f8 to make way (and that last move was not f7-f5)
(The penultimate move was g2xTh3 or L-e2) (2019-1-29)
Henrik Juel: It may be clearer to reverse the two sequences and rewrite:
g7xDh6 before L-g7 (or L-h8) before f7-f6 before Tf8-f7 (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 31 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
80 - P0003085
Raymond Smullyan
32 The Chess Mysteries of the Arabian Knights 1981
P0003085
(14+13)
Der wK und die wD haben noch nicht gezogen und sind noch nicht angegriffen worden. Was geschah mit dem sBg7?
Henrik Juel: Dd8 is [Pg7] promoted on g1
White captured L or S on b3 and some original black officer (not S) on c3, before [Ta1] could get out to help [Pg7] promote on g1
Promoting to LT does not work, so after d2xDc3 Black played gxT...xLg2-g1=D (with a screen on f1)
. (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 32 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
81 - P0003086
Raymond Smullyan
33 The Chess Mysteries of the Arabian Knights 1981
P0003086
(14+14)
Der sK und die sD haben noch nicht gezogen, Weiß darf noch rochieren. Welches ist der schwarze Königsturm?
Henrik Juel: Ta2
The only feasible sequence is
a2xLb3 before Ta1-f6 before g7xTf6 before Th8-a2 before b2xLa3 before c7xLb6 before Ta8-h3
. (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 33 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
82 - P0003087
Raymond Smullyan
34 The Chess Mysteries of the Arabian Knights 1981
P0003087
(14+13)
Beide Seiten dürfen noch rochieren, die wD ist nie angegriffen worden, die sD nur einmal. Welcher weiße Offizier hat einen illegalen Zug gemacht?
Henrik Juel: Silly problem
Retroanalysis requires legality throughout
Silly answer:
[Ta1] illegally reached e6 early, allowing d7xTe6 and then e.g. d2xDc3
. (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 34 Die Schachgeheimnisse des Kalifen 1984
R11 Phénix 275-276, p. 10810, 07-08/2017
R11 Phénix 275-276, p. 10815, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-9 more...
83 - P0003088
Raymond Smullyan
35 The Chess Mysteries of the Arabian Knights 1981
P0003088
(13+16)
Ergänze den weißen Damenläufer, wenn möglich. Wenn nicht: wo wurde er geschlagen?
Henrik Juel: [Lc1] was captured on c1
The sequence must have been
d7xDc6 before Lc8-a2 before b2-b3
. (2019-1-29)
comment
Keywords: Where was piece x captured?
Genre: Retro
Reprints: 35 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
84 - P0003089
Raymond Smullyan
36 The Chess Mysteries of the Arabian Knights 1981
P0003089
(13+15)
Der weiße Damenläufer ist nicht auf seinem Ausgangsfeld geschlagen worden. Ergänze, wenn möglich, den weißen Damenläufer oder zeige, auf welchem Feld er geschlagen worden ist!
Henrik Juel: [Lc1] was captured on b2
[Lc8] could not get out before d7xDc6, so La2 must be promoted: a3xLb2-b1=L
. (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 36 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
85 - P0003090
Raymond Smullyan
37 The Chess Mysteries of the Arabian Knights 1981
P0003090
(13+15)
Die wD wurde auf c6 geschlagen, Weiß darf noch rochieren. Ergänze einen weißen Läufer. Ergänze, wenn möglich, den schwarzen Königsläufer oder zeige, auf welchem Feld dieser geschlagen worden ist!
Henrik Juel: Add wLh8, [Lf8] was captured on h6
[Lc1] was captured on c1, so the added wL must be [Pg2] playing g5xLh6-h8=L
. (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 37 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
86 - P0003091
Raymond Smullyan
38 The Chess Mysteries of the Arabian Knights 1981
P0003091
(12+14)
Weiß hat einen Springer vorgegeben, der wK hat noch nicht gezogen. Nur eine Figur ist auf ihrem Ausgangsfeld geschlagen worden, und dies war nicht die erste Figur, die geschlagen worden ist. Befindet sich der schwarze Damenläufer noch auf dem Brett?
Henrik Juel: Yes
The sequence must have been
c2-c3 before e7xDf6 before Sb3xLc1 before Ta1-c1 before Sa3-b1 before b2xLa3 before b7xTa6
Only then could [Lc8] get out (it was not captured at home, because [Lc1] was), but White cannot have captured it, so it is still on the board somewhere
. (2019-1-29)
comment
Keywords: Conditional problem, Odds game
Genre: Retro
Reprints: 38 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
87 - P0003244
M. Geofth
1022 L'Echiquier de Paris 1954
1. -2. Preis e.a.
P0003244
(5+10) cooked
h#4
b) sBb2 statt wBb2
a) 1. dxe3ep Kd4 2. Tc6 Kd5 3. Dg6 dxe3 4. Kf5 e4#
b) 1. Se3 Lxb2 2. Dg1 Lxd4 3. Dg4 Lxf6 4. Lg3 dxe3#
play all play one stop play next play all
Cook: NL
b) 1. Da2 Lxb2 2. De6 Lxd4 3. h3 Lxf2 4. Ke5 Lg3#
Yuri Bilokin: Correction: bpb2, +bnh5 2.1… b7/8/5p2/7n/3pPknp/3K1p2/1prP1b2/1qB5 (4+12)
1.dxe3 e.p. Kd4 2.Rc6 Kd5 3.Qg6 dxe3+ 4.Kf5 e4#
1.Se3 Bxb2 2.Qg1 Bxd4 3.Qg4 Bxf6 4.Bg3 dxe3# (2019-3-13)
comment
Keywords: En passant as key, Check Protection
Genre: h#, Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2017-7-11 more...
88 - P0003927
Herbert Hultberg
Springaren 1979
P0003927
(10+2)
-1w, dann #1
VRZ, Typ Proca
R: 1. g7xSh8=S? (illegale w Bauernstruktur)
R: 1. c7xSb8=S!, dann 1. c8=D#
play all play one stop play next play all
klären: # vor 1 Zügen!? - 1 Zug oder n Zügen! (VF)
Mario Richter: #1 vor 1 ist möglich: R: c7xSb8=S, dann 1.c7-c8=D#
Der spiegelbildliche Versuch R: g7xSh8=S, dann 1.g7-g8=D# scheitert an der Illegalität der wB-Struktur. (Das erklärt aber natürlich noch nicht das 'VRZ,Typ Proca'.) (2009-12-8)
Henrik Juel: Hultberg also made Høeg retractors, so maybe the type designation just underscores that this problem is not a Høeg retractor. If it were, it would be unsolvable: Black chooses to supplement some other officer than a knight on b8, and then there is no mate. (2009-12-11)
Mario Richter: Thank you, Henrik! Your explanation sounds very plausible to me. (2009-12-11)
paul: Actually, this is a help retractor. (2018-12-14)
comment
Keywords: Symmetrical position, Defensive Retractor, Type Proca, Asymmetrical solution
Genre: Retro
Reprints: RA135 diagrammes 49 01-02/1981
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-14 more...
89 - P0004043
Karl Fabel
Parallele 50 1950
P0004043
(2+1)
Weiß nimmt 1 Zug zurück, dann #2
R: 1. "0-0", dann 1. "0-0-0" Ka1 2. Ta3#
play all play one stop play next play all
Veröffentlicht in der Rubrik "Professeur Cosinus"
Mario Richter: Vorwärtsspiel m.E. zumindest teilweise vorweggenommen durch P1359470. (2019-1-12)
A.Buchanan: This one, in constrast to P1359470, remains a joke and a good one. (2019-1-12)
comment
Keywords: Odds game, Help retractor, Joke, Castling (wkwg)
Genre: Retro
Reprints: 490 La Composition Contemporaine [Martin] 1951
(9) diagrammes 86 07-09/1988
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2015-8-12 more...
90 - P0004066
S. N. Ravishankar
2069 diagrammes 89 04-06/1989
P0004066
(2+1)
#1 vor 6
VRZ, Typ Proca
S N Ravi Shankar: This problem is not mine. (2019-1-2)
Mario Richter: My first guess for the solution was:
R: 1. Ke2xLf1 2. Kd3xLe2 3. Kc4xLd3 4. Kb5xLc4 5. Ka6xLb5 Lc6-b5+ 6. Sd7xLb8, dann 1. Sb6#, but that doesn't work because of 5. ... Ld7-b5+!
Does someone see (or know) the correct solution? (2019-1-3)
Henrik Juel: No, because with 1... Lh3-f1+, 5.Ka6-b5 thr. 6.Sd7xLb8 fails similarly on 5... Ld7-h3 (2019-1-3)
comment
Keywords: Defensive Retractor, Type Proca, Rex solus (s), Aristocrat
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-4 more...
91 - P0004348
Edward J.M.D.P. Dunsany
1 The Week-End Problems Book , p. 179, 1932
P0004348
(8+16)
#4
(Brettdrehung 180°)
1,2) 1. Sc6,Sd7 Sf3 2. Sb4,Sc5 Se5 3. Dxe5 ... 4. Sd3#
play all play one stop play next play all
Das Brett muss um 180 Grad gedreht werden, da sK und sD vertauscht sind.
AB: Two variant solutions.
(In any case, board must be rotated by 180 degrees, then 1 Nc6/d7 Nf3 2 Nb4/c5 Ne5 3 Qxe5 ~ 4 Nd3# (2002-4-3)
more ...
comment
Keywords: Joke, Board Rotation (180), Illegal position
Genre: Retro, n#
Reprints: Problem 101-102 09/1966
73 100 Classics of the Chessboard 1983
17 Die gefesselte Zeit , p. 137, 1987
(L) Die Schwalbe 151 02/1995
Karl 4/2018, p. 57, 12/2018
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-6 more...
92 - P0004845
Dmitri W. Pronkin
4833v Die Schwalbe 84 08/1984
1. Preis
P0004845
(14+1)
BP in 26,5
1. Sh3 g5 2. Sf4 gxf4 3. Sa3 f3 4. gxf3 Sf6 5. Lg2 Se4 6. fxe4 d5 7. exd5 Sc6 8. dxc6 Dd3 9. exd3 h5 10. Dg4 hxg4 11. cxb7 g3 12. hxg3 f5 13. Th2 f4 14. gxf4 e5 15. fxe5 Ld6 16. exd6 Th3 17. dxc7 Te3+ 18. fxe3 a5 19. Kf2 Ta6 20. Kg3 Tc6 21. Kh4 Tc3 22. dxc3 Le6 23. Ld2 Lb3 24. cxb3 a4 25. bxa4 Kf7 26. Ld5+ Kg6 27. Lf7+
play all play one stop play next play all
Henrik Juel: Mario, can your rawbats test this one? (2018-12-9)
Mario Richter: White pawns captured all missing black men, and we know exactly on which squares all these captures took place. So one testing idea would be to generate all possible mappings M: BLACK_PIECES -- CAPTURE_SQUARES and use these mappings as constraints for programs like 'jacobi' or 'rawbats'.
The main task is to find a subset M' of M which reduces the number of test cases from approx. 15! to a manageable size.
Can you provide some mathematical/logical insight how this might be done?! (Some observations that might be helpful are: Bishops could only have been captured on squares of their own color, Ph7 captured at least once and he or Pg7 either promoted or did the last remaining black capture,so most of the other black pawns never left their homefile, ...) (2018-12-10)
Henrik Juel: I have no further insights, Mario (2018-12-11)
comment
Keywords: Unique Proof Game, Massacre PG, Rex solus (s)
Genre: Retro
Reprints: 118 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
93 - P0005374
Stefan Höning
6638 feenschach 111 01-09/1994
P0005374
(2+1)
Ergänze wK, wD, wT, wL, wS, wB; sK, 2sTT, sL zu einem weißen L.C.!
+wKd3,wDd7,wTe4,wLc2,wSc5,wBd2,sKa4,sTd1d8,sLb1
play all play one stop play next play all
FM: "Bemerkenswerte Idee, dieser Semi-Legal Cluster."
3/III
Henrik Juel: The stipulated position is not an ordinary Legal cluster (LC), but an easier variant called a White LC, defined as a legal position that becomes illegal if you remove any one white man (so removing a black man is irrelevant)
The solution position is legal, as last move could be Sb3-c5++
Removing Lc2, Pd2, Dd7, or Te4 puts both kings in check, removing Pb4 or Pb5 gives an illegal triple check, and removing Sc5 gives impossible check from wLc2 (and removing Kd3 obviously gives an illegal position) (2019-2-18)
Henrik Juel: Alfred has waved his magic wand again, so you don't need a board, just click on the little right-arrow, then move the cursor up, and, presto, the diagram shows the solution
I agree with solver FM that this is a clever way to avoid a condition (like Checkless Chess), but the idea hasn't caught on; at least this is the only White LC in the PDB (2019-2-19)
Olaf Jenkner: Good idea: Alfred used a zero-position and the solution as part a) (2019-2-19)
A.Buchanan: Sorry been very busy. One feature still missing from the animation is the ability to return to the zero position. Compare Julia's Fairies animation, where there are *** at the top which you can click on. (2019-2-20)
comment
Keywords: Legal cluster (w)
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-2-18 more...
94 - P0005567
Raymond Smullyan
39 The Chess Mysteries of the Arabian Knights 1981
P0005567
(16+13)
Weiß und Schwarz dürfen noch rochieren. Welcher der 3 wSS muß vom Brett entfernt werden, damit die Stellung legal wird?
-wSg1
play all play one stop play next play all
Henrik Juel: .
The sequence must have been
b2xLc3 before c7xDb6 before g2xDh3 before g1=L
and f2-f3 before Lg1-g7
A wS could not reach g1 after Lg1 had left, so Sg1 must be removed
. (2019-1-29)
comment
Keywords: Conditional problem, Non-standard material, Illegal position, Remove pieces
Genre: Retro
Reprints: 39 Die Schachgeheimnisse des Kalifen 1984
R12 Phénix 275-276, p. 10810, 07-08/2017
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
95 - P0005568
Raymond Smullyan
40 The Chess Mysteries of the Arabian Knights 1981
P0005568
(14+15)
Keiner der KK hat gezogen.
Wo wurde der weiße Königsturm geschlagen?
Henrik Juel: On b6
The sequence must have been
b7xSc6 before g2xTh3 or g3xTh4 before [Th1] could get out
So it was captured on b6
. (2019-1-29)
comment

Genre: Retro
Reprints: 40 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
96 - P0005569
Raymond Smullyan
41a The Chess Mysteries of the Arabian Knights 1981
P0005569
(14+14)
Die KK und die DD haben weder gezogen noch sind sie angegriffen worden. Welcher Offizier muß vom Brett entfernt werden, damit die Stellung legal ist?
Henrik Juel: Lf1
No S was captured by a pawn
The pawn captures were f2xLe3, b7xTc6, g2xTf3, in this order, so Lf1 must be removed
. (2019-1-29)
comment
Keywords: Conditional problem, Remove pieces
Genre: Retro
Reprints: 41a Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
97 - P0005570
Raymond Smullyan
41b The Chess Mysteries of the Arabian Knights 1981
P0005570
(14+14)
Kein König hat je gezogen und keine Dame ist jemals angegriffen worden. Welche Figur muß vom Brett entfernt werden, damit die Stellung legal wird?
Henrik Juel: .
Seems to be unsolvable, as no white man could be captured on c6 to release [Ta8,Lc8]
. (2019-1-29)
Mario Richter: Wrong stipulation. The correct one is:
""This time, neither king has moved, and neither queen has been under attack. Where is the genie [the piece to be removed to make the position legal] now?" (2019-1-30)
A.Buchanan: I suppose sometime we should put English & French translations of these wretchedly long Smullyanesque stipulations. It's the kind of thing that novice visitors might come for. (2019-1-30)
Henrik Juel: With Mario's condition modification:
Remove Lc8, so that Dd8 could step aside to c8, allowing b7xSc6 (2019-1-30)
comment
Keywords: Conditional problem, Remove pieces
Genre: Retro
Reprints: 41b Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-30 more...
98 - P0005571
Raymond Smullyan
42 The Chess Mysteries of the Arabian Knights 1981
P0005571
(15+13)
Welcher der beiden LLh2 und h4 muß entfernt werden, damit Weiß zwingend in 2 Zügen gewinnen kann?
Henrik Juel: Lh4
Suppose that Black may castle
Then [Ta8] was captured in its corner, leaving a light-squared L and a h-pawn as missing men for White and for Black
d2xc3 and e7xf6 were captures on dark squares, so both missing pawns must have promoted
White could not capture h6xg7 on a dark square, so first Black captured h3xLg2 allowing White to play h2-h7xLg8 later
But then we cannot explain Lh2
So remove Lh4 and play 1.Da6 thr. 2.Dc8#; Black cannot defend, because he may not castle
(The position without Lh4 is clearly legal, because Black need not promote)
. (2019-1-29)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 42 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
99 - P0005572
Raymond Smullyan
43 The Chess Mysteries of the Arabian Knights 1981
P0005572
(13+14)
Die KK und DD haben noch nicht gezogen. Welcher der 4 SS ist in Wirklichkeit ein Läufer?
Henrik Juel: Sc6
White captured 3 times, but only 2 black men are missing, so Sc6 or Sf6 must be a wL
Only wLc6 works, as g7xLh6 is needed (2019-1-30)
comment
Keywords: Conditional problem
Genre: Retro
Reprints: 43 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
100 - P0005573
Raymond Smullyan
44 The Chess Mysteries of the Arabian Knights 1981
P0005573
(14+15)
Es sind keine weißen UWF auf dem Brett. Der wB b3 kam von b2. Welcher der sSS ist eine UWF?
Henrik Juel: Sh8
[Pa2] promoted on b8, so Sa8 is original
Later [Pd7] promoted on b1, so Sa1 is original (2019-1-30)
comment
Keywords: Conditional problem, Non-standard material
Genre: Retro
Reprints: 44 Die Schachgeheimnisse des Kalifen 1984
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2018-3-7 more...
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