1211 problem(s) found in 1547 milliseconds (displaying 100 problem(s)).

1 - P0000007
Andrej N. Kornilow
Andrey Frolkin
Dmitri W. Pronkin

5408 Die Schwalbe 97 02/1986
P0000007
(15+15)
BP in 33,0
1. Sc3 Sc6 2. Se4 Se5 3. c3 c6 4. Da4 Da5 5. b3 b6 6. La3 La6 7. Lc5 Lc4 8. Le3 Le6 9. Lh6 Lh3 10. gxh3 gxh6 11. h4 h5 12. Lh3 Lh6 13. Lf5 Lf4 14. Sh3 Sh6 15. Tg1 Tg8 16. Tg3 Tg6 17. Te3 Te6 18. f3 f6 19. Kf2 Kf7 20. Tg1 Tg8 21. Tg4 Tg5 22. Sg3 Sg6 23. Lb1 Lb8 24. Td4 Td5 25. Tdd3 Tdd6 26. Df4 Df5 27. Te4 Te5 28. Ke3 Ke6 29. Sf2 Sf7 30. Sg4 Sg5 31. Sh6 Sh3 32. Sg8 Sg1 33. Dh6 Dh3
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Henrik Juel: After a couple of hours Natch 3.1 had not even found the symmetrical solution (2018-12-7)
comment
Keywords: Unique Proof Game, Symmetrical position
Genre: Retro
Reprints: 581 Ukrainisches Album 1986-1990
111 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Nikolai Beluhov, 2011-5-6 more...
2 - 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#
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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...
3 - 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+
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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...
4 - P0000111
Andrey Frolkin
Leonid Lyubashevsky

6330 Die Schwalbe 112 08/1988
4. ehrende Erwähnung
P0000111
(28+0)
Färbe die Steine!
BP in 11,0
1. h4 f5 2. Th3 Kf7 3. Tb3 De8 4. Tb6 axb6 5. g3 Ta3 6. Lg2 Tc3 7. Lc6 dxc6 8. dxc3 Le6 9. Dd8 Lb3 10. axb3 Dd7 11. Ta8 Dd1+
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Henrik Juel: C+ by Natch 3.1
The colored position is 'natural' except for wTa8, wDd8, and sDd1 (2018-12-7)
comment
Keywords: Unique Proof Game, Coloring problem, Interchange
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2005-12-27 more...
5 - P0000129
Manfred Seidel
6575 Die Schwalbe 116 04/1989
P0000129
(13+12) cooked
BP in 18,5
1. c4 Sa6 2. c5 Sxc5 3. Sf3 Se4 4. Se5 Sg3 5. Sxd7 e5 6. Sb6 axb6 7. hxg3 Ta3 8. Txh7 Tf3 9. gxf3 Lf5 10. Lh3 Lxh7 11. Lc8 f5 12. d3 Kf7 13. Le3 Kg6 14. Sd2 Kh5 15. Tc1 g6 16. Tc4 Lh6 17. Te4 Df8 18. Ld4 Le3 19. Le6
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Henrik Juel: Here is one of the three similar cooks
1.Sg1-f3 Sb8-c6 2.Sf3-e5 Sc6-d4 3.Se5xd7 Be7-e5
4.Sd7-b6 Ba7xb6 5.Sb1-c3 Ta8-a3 6.Sc3-b1 Ta3-g3
7.Bh2xg3 Sd4-f3 8.Bg2xf3 Lc8-f5 9.Th1xh7 Lf5xc2
10.Lf1-h3 Lc2xh7 11.Lh3-c8 Bf7-f5 12.Bd2-d3 Ke8-f7
13.Lc1-e3 Kf7-g6 14.Sb1-d2 Kg6-h5 15.Ta1-c1 Bg7-g6
16.Tc1-c4 Lf8-h6 17.Tc4-e4 Dd8-f8 18.Le3-d4 Lh6-e3
19.Lc8-e6 (2018-12-7)
comment
Keywords: Unique Proof Game
Genre: Retro
Reprints: 146 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2004-8-27 more...
6 - 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...
7 - P0000143
Nikita M. Plaksin
6689 Die Schwalbe 118 08/1989
4. Lob
P0000143
(13+9)
Löse die Stellung auf!
Madrasi RI
R: 1. Se6xDd8 Bd2xTe1=L 2. Tb1-e1 c3xTd2 3. Tb8-b1 b4xTc3 4. b7-b8=T 5. a6xT(S)b7
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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
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-15 more...
8 - P0000172
Dmitri W. Pronkin
6991v Die Schwalbe 123 06/1990
P0000172
(13+13)
BP in 24,5
1. Sc3 Sf6 2. Se4 Sd5 3. Sg5 Sc3 4. Sxh7 Sb1 5. Sxf8 Th5 6. h4 Tg5 7. hxg5 Kxf8 8. Th6 Kg8 9. Tb6 Kh7 10. g6+ Kh6 11. e4 Kg5 12. Lb5 Kf4 13. Ke2 Ke5 14. Kf3 Kd4 15. Kf4 Kc5 16. b4+ Kxb4+ 17. La3+ Kxa3 18. Df3+ Kb2 19. a4 Kc1 20. Se2+ Kd1 21. Sc1+ Ke1 22. Sd3+ Kf1 23. Sb2+ Kg1 24. Lf1 Kh1 25. Dd3
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Henrik Juel: The long promenade is made by k, not K (2018-12-7)
comment
Keywords: Unique Proof Game, Promenade (K)
Genre: Retro
Reprints: 579 Ukrainisches Album 1986-1990
113 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2005-12-27 more...
9 - P0000231
Jasper van Atten
7376 Die Schwalbe 129 06/1991
3. Preis
P0000231
(16+13)
BP in 20,0
1. h4 a5 2. h5 a4 3. h6 Ta5 4. hxg7 Sh6 5. g8=T Sa6 6. Tg3 Tg8 7. c4 Tg6 8. c5 Lg7 9. c6 Kf8 10. cxb7 De8 11. b8=T Lb7 12. Td8 d6 13. Td7 Dd8 14. b3 Ke8 15. Lb2 Lf8 16. Lg7 Tf5 17. Tc3 Tf3 18. exf3 Sb8 19. La6 Lc8 20. Lb7 Sg8
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Henrik Juel: C+ by Natch 3.1 (5 min.) (2018-12-7)
comment
Keywords: Unique Proof Game, Non-standard material, Promotion (TT)
Genre: Retro
Reprints: 131 Shortest Proof Games 11/1991
feenschach 137 08-09/2000
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2006-1-9 more...
10 - 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!
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"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...
11 - P0000372
Andrey Frolkin
8422 Die Schwalbe 145 02/1994
1. ehrende Erwähnung
P0000372
(14+12)
BP in 23,5
1. Sh3 g5 2. Sf4 g4 3. h3 g3 4. Th2 gxh2 5. Sh5 h1=S 6. f4 Sg3 7. f5 Sxf1 8. f6 Sh2 9. fxe7 f5 10. Kf2 f4 11. Dg1 f3 12. Kg3 Sf6 13. Dxa7 c5 14. Sc3 Sc6 15. Db8 Ta3 16. Sa4 Tc3 17. bxc3 f2 18. La3 f1=T 19. Lb4 Th1 20. Tf1 Db6 21. Tf3 Sd8 22. Te3 Sf1+ 23. Kf3 De6 24. exd8=T+
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"Uff, das war bannig oder sakrisch schwierig, je nach landschaftlicher Mundart. Daß die schwarzen UW-Steine den Platz tauschen, war wohl das Uranliegen des Autors. Aber dazu hat er sich doch ganz Hübsch etwas einfallen lassen: Falsche Fährten legen und Unerwünschtes verunmöglichen - das ist ihm bestens gelungen" (HHS) "Dieser Platztausch der umgewandelten Figuren fasziniert mich sehr" (RS) 3,5/III/6L.
Henrik Juel: Unfortunately cooked
1.Sg1-h3 Sb8-c6 2.Bf2-f4 Sc6-e5 3.Bf4-f5 Bg7-g5
4.Sh3-f4 Bg5-g4 5.Bf5-f6 Bg4-g3 6.Bf6xe7 Bf7-f5
7.Sf4-h5 Bf5-f4 8.Bh2-h3 Bf4-f3 9.Th1-h2 Bg3xh2
10.Ke1-f2 Bh2-h1=T 11.Kf2-g3 Th1xf1 12.Sb1-c3 Tf1-h1
13.Dd1-g1 Se5-g4 14.Dg1xa7 Sg4-h2 15.Da7-b8 Ta8-a3
16.Sc3-a4 Ta3-c3 17.Bb2xc3 Bf3-f2 18.Lc1-a3 Bf2-f1=D
19.La3-b4 Df1-f5 20.Ta1-f1 Df5-e6 21.Tf1-f3 Sg8-f6
22.Tf3-e3 Sh2-f1 23.Kg3-f3 Bc7-c5 24.exd8=T+ (2018-12-7)
comment
Keywords: Unique Proof Game, Interchange, Promotion (ts)
Genre: Retro
Reprints: H22 FIDE Album Annexe 1992-1994 2003
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2005-12-27 more...
12 - P0000393
Pascal Wassong
8552 Die Schwalbe 147 06/1994
2. ehrende Erwähnung
P0000393
(10+16) C+
BP in 23,0
1. h4 Sc6 2. Th3 Se5 3. Tb3 Sg4 4. Tb6 axb6 5. c4 Ta3 6. Da4 Th3 7. g3 Th1 8. Lg2 Sh2 9. Lc6 dxc6 10. Kd1 Lh3 11. Kc2 e6 12. Kb3 Lb4 13. c5 Lxd2 14. Db4 Lh6 15. Le3 Dxh4 16. Sd2 f6 17. Tc1 Kf7 18. Tc4 Kg6 19. Tg4+ Kh5 20. Tg6 hxg6 21. Lg5 fxg5 22. Ka4 Sf6 23. b3 Sh7
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more ...
comment
Keywords: Unique Proof Game, Ornament
Genre: Retro
Computer test: Henrik Juel: C+ by Natch 3.1 (4 min.) (2018-12-8)
Reprints: (I) Phénix 91 12/2000
Input: Gerd Wilts, 1995-6-3
Last update: Erich Bartel, 2018-12-8 more...
13 - 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...
14 - P0001110
Michel Caillaud
3396 Die Schwalbe 67 02/1981
4. Preis
P0001110
(14+12)
Wieviele Züge sind seit dem letzten Bauernzug mindestens geschehen?
Renny Bosch: I believe the minimum number of moves since the last pawn move is 68, based on the following PG (or SPG?): 1. g4 Nc6 2. Bg2 Na5 3. Bc6 Nb3 4. axb3 Nf6 5. Nc3 Ne4 6. Nd5 Nc3 7. dxc3 Rg8 8. Qd4 Rh8 9. Qb6 axb6 10. Be3 Rg8 11. Bc5 Rh8 12. Bb4 Rg8 13. Ra5 Rh8 14. Rc5 bxc5 15. Ba5 Rg8 16. Bb6 Rh8 17. Ba7 Rg8 18. Bb8 Rh8 19. Ba4 Ra6 20. Kd2 Re6 21. Kd3 Re5 22. Kc4 Re4+ 23. Kb5 Rc4 24. bxc4 Rg8 25. Bb3 Rh8 26. Nh3 Rg8 27. Ra1 Rh8 28. Ra7 Rg8 29. Nb6 Rh8 30. Na8 Rg8 31. Nf4 Rh8 32. Nd5 Rg8 33. Ndb6 h6 34. Na4 b6 35. Ba2 Bb7 36. Bb1 Be4 37. g5 Bh7 38. g6 Rh8 39. gxh7 { the last pawn move } g6 40. Rb7 Bg7 { move bB, bK, bQ out of row 8 } 41. Ba7 Be5 42. Rb8 Kf8 43. Ka6 Kg7 44. Kb7 Qg8 45. Rf8 Kf6 46. Kc8 { allow bR to pass wK } Qg7 47. Rg8 Ke6 48. Kd8 Qf6 49. Ke8 Qf5 50. Kf8 Bf4 51. Kg7 Qg5 { reverse order of the two rooks }52. Rb8 Rc8 53. Rb7 Rd8 54. Bb8 Rc8 55. Ra7 Rd8 56. Ra5 Rc8 57. Ba7 Rb8 58. Rb5 Rb7 59. Bb8 Ra7 60. Rb3 Ra5 61. Ra3 Rb5 62. Ra1 Rb3 63. Ba2 Ra3 64. Bb3 Ra2 65. Rd1 Ra1 66. Rd2 Re1 67. Rd1 Rf1 68. Ra1 Rb1 69. Ra3 Rc1 70. Ba2 Ra1 71. Bb1 Ra2 72. Rb3 Ra3 73. Rb5 Rb3 74. Ra5 Ra3 75. Ra7 Rb3 76. Rb7 Ra3 77. Ba7 Rb3 78. Rb8 Ra3 79. Rh8 Qf6+ 80. Kf8 { move bK past wR } Qg7+ 81. Ke8 Kf6 82. Kd8 Be5 83. Kc8 Qg8+ 84. Kb7 Kg7 85. Ka6 Kf8 86. Kb5 Ke8 87. f3 Kd8 88. Ba2 Kc8 89. Bb1 Kb7 90. Ba2 Qg7 91. Rg8 Qf6 92. Bb1 Qe6 93. Ba2 Bh8 94. Rg7 { put wR into pocket, and final cleanup } Kc8 95. Ka6 Kd8 96. Kb7 Ke8 97. Kc8 Kf8 98. Kd8 Rb3 99. Bb1 Rb5 100. Ba2 Ra5 101. Bb8 Ra7 102. Bb1 Rb7 103. Ba7 Qc6 104. Ba2 Qb5 105. Bb1 Qb4 106. Ba2 Qa3 107. Rg8# (2007-4-24)
Michel Caillaud: the exact stipulation ends "mindestens geschehen".
(in english : "minimum number of moves since the last Pawn move?").
the last Pawn move is f2-f3,that must be interposed before g7-g6 as otherwise the 50-moves rule would have been violated.
the answer is a minimum of 15,0 moves with a retro-play running as :
-1.Tg7-g8# ...-16.f2-f3! ... -65...g7-g6
with 49,5 moves between g7-g6 and f2-f3 the 50-moves rule has been respected (2007-9-12)
Michel Caillaud: more detail on intended retro-play :
-1.Tg7-g8# … -4…De6-c6 … -8…Tb3-b5 -9.Kb5-a6 Ta3-b3+ -10.La7-b8 … -13…Kb7-c8 -14.Tg8-g7 Ld4-h8
-15.Tf8-g8 Df6-e6 -16.f2-f3! Dg7-f6 -17.Th8-f8 Dg8-g7 -18.Lb1-a2 Ta1-a3 -19.La2-b1 … -24… Kf6-g7 -25.Kb7-a6 Dg7-g8 -26.Tb8-h8 Ke5-f6 -27.Kc8-b7 … -28… Dh4-f6 -29.Ke8-d8 … -35… Td2-d1 -36.Ta3-b3 … -37.Lb3-a2 … -39.Th1-a1 Td1-d2 -40… Ta1-d1 -41.Kg7-f8 Ta3-a1 -42.La2-b3 …-48… Th8-b8 -52.Tb7-a7 … -53.La7-b8 … -55.Tg8-b8 … -59.Kç8-d8 Kf6-e5 -60.Kb7-ç8 Kg7-f8 -61.Tb8-g8+ Kf8-g7 -62.Kc8-b7+ Ke8-f8 -63.Tb7-b8 Lg7-d4 -64.Lb8-a7 Lf8-g7 -65.Ta7-b7 g7-g6 (2007-9-18)
Henrik Juel: After -1.Tg7-g8# the main parts of the resolution are
(s/w mean black/white)
sDa3 out, sTb7 to a3, wKe8 to b5, sKf8 to b7, wTg7 to h8 and sLh8 to d4, sD to g8, sKb7 via g7 to e5, sDg8 out, wKb5 to g7, sTa3 to d2, wTh8 to e1, sTd2 to h8, wTe1 to g8,
(the rooks have switched place)
wKg7 to b7, wTg8 to b8, wKb7 to c8, sKe5 to e8, sLd4 to f8,
-65... g7-g6 -66.g6xLh7
(so -16.f2 was needed to avoid draw by the 50 moves rule)
wTb8 to h1, wKc8 to b5, sD to d8, sLh7 to c8,
-88... b7-b6
wSa8 out, wLa7 to a5,
-99... b6xTc5
wTc5 to a1, wLa5 to c1,
-111.d2xTc3
sTc3 to a8 and wSa4 to b1, wLa2 to a4
-222.b3xSc4 a7xDb6 -223.a2xSb3 (2018-12-5)
Henrik Juel: It is difficult to avoid typos in such a mess
in line 3, wKd8 to b5, not e8
Michel also seems to have made some typos:
49.0 moves between -16.f2 and -65... g7, not 49.5
-25... Kf6, not 24 (may have implications for the solution) (2018-12-5)
more ...
comment
Keywords: 50 move rule
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: hpr, 2008-8-26 more...
15 - 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...
16 - P0001404
Jean Roche
278 Europe Echecs 182 01/1974
Lob
P0001404
(7+13) C+
h#2
if white can castle: 1. Td7 0-0-0 2. Kd8 Dxd7#
if black can castle: 1. Td7 Txa7 2. 0-0-0 Ta8#
play all play one stop play next play all
NN: The above is basically two parts of a single solution depending on the history of the game and not two different solutions.

Proof of why castling rights are mutually exclusive: Let's assume black CAN castle. Now, the bPs piled up on h-file implies six captures of white units and these can only be wRBBNN & wPe2. Because all other possibilities involve promotion of wPs on d8/e8/f8 followed by their capture by bPs, interfering with black's castling right. Next, we observe that wRh1 getting captured by bPs implies one of the following two things: (i) wKe1 moved to let wRh1 out of the pawn-chain or (ii) wPg2,h2 cross-captured on h3,g3 respectively to facilitate the escape of wRh1. Furthermore, option (ii) necessitates bPd7 to be promoted to d1 so that it can be captured by wPs, implying wKe1 had to move anyway to let bPd7 promote.
Thus, Black can castle implies wKe1 moved and white can't castle. Contrapositively, white can castle will imply that black can't. (2018-11-29)
Henrik Juel: Nice analysis, Satanick (2018-11-29)
NN: Thanks Henrik Juel. Hope there are no mistakes. (2018-11-29)
Yoav Ben-Zvi: The claim that retaining Black castling requires an uncapture of a wR by Black's h-file pawns is not accurate. Consider the case that all 6 of these bP uncaptures are of wBs and wNs. In this case 2 of the uncaptured White pieces unpromote. Both could be unpromoted (on f8 or d8) by an uncapture from e7. This scenario requires a third wP uncapture (on the e file) so one of White's uncaptures is accounted for by [bPd7]. The direct uncapture of [bPd7] (on the e file) or its unpromotion without stepping on d2 requires this pawn to uncapture the wR, confirming the conclusion of mutually exclusive castling. A similar argument works for the case that the Black h file pawns play bPe7xwPf6 along with 5 uncaptures of WNs and wBs. (2018-12-3)
Henrik Juel: Now we can test
C+ by Popeye 4.61 (and analysis)
The main content is the retro analysis, of course, but as a helpmate problem the repeated 1.Td7 detracts (2018-12-3)
more ...
comment
Keywords: Partial Retro Analysis (PRA), Castling (wgsg), Castling, mutual exclusive
Genre: h#, Retro
Computer test: Popeye 4.61
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-3 more...
17 - 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...
18 - P0001613
Andrey Frolkin
483 Europe Echecs 343/344 07/1987
P0001613
(13+14) C+
BP in 21,5
1. a4 Sc6 2. Ta3 Sd4 3. Tg3 Sxe2 4. Kxe2 g5 5. Ke3 Lh6 6. Lc4 Kf8 7. La2 Kg7 8. c4 Kf6 9. Db3 Ke6 10. Db6+ axb6 11. b4 Ta5 12. Lb2 Tb5 13. Lg7 Sf6 14. Sf3 Dg8 15. Lf8 Dg6 16. Te1 Tg8 17. Te2 Tg7 18. Se1 g4+ 19. f4 gxf3ep+ 20. Tg5 Sg8 21. c5+ d5 22. cxd6ep+
play all play one stop play next play all
Ein schwarzer und ein weißer ep-Schlag.
more ...
comment
Keywords: Unique Proof Game, En passant
Genre: Retro
Computer test: Natch 3.1 (5 min.)
Reprints: 575 Ukrainisches Album 1986-1990
94 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-6 more...
19 - 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...
20 - P0002272
Andrey Frolkin
Themes-64 1985
Lob e.a.
P0002272
(12+14) C+
BP in 20.5
1. Sf3 a5 2. Sd4 a4 3. Sb3 axb3 4. a3 Ta4 5. Ta2 bxa2 6. h4 axb1=S 7. h5 Sc3 8. h6 Sxd1 9. hxg7 h6 10. Th5 Th7 11. Ta5 b5 12. Ta8 Ta7 13. f3 La6 14. f4 Dc8 15. f5 Db7 16. f6 Df3 17. gxf3 Kd8 18. Lh3 Kc8 19. Lg2 Kb7 20. Lh1 Kc6 21. f4+
play all play one stop play next play all
Henrik Juel: C+ by Natch 3.1 (2 min.)
Tempo loss at 13.f2-f3-f4 and 18.Lf1-h3-g2-h1 (2018-12-6)
Joost de Heer: IMO f2-f3-f4 isn't a tempo loss, as the pawn is needed for shielding. (2018-12-7)
Henrik Juel: I see no shielding by [Pf2], Joost
White could play 13.f4?, but he would run out of moves
White plays 17.gxf3, and this wP will later shield, so wLg2 does not check sKb7, but that is a different story (2018-12-7)
comment
Keywords: Unique Proof Game, Non-standard material, Loss of tempo (BL3), Promotion
Genre: Retro
Computer test: Natch 3.1 (2 min.)
Reprints: 63 Shortest Proof Games 11/1991
3397 U.S. Problem Bulletin 102/103 07-10/1995
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-7 more...
21 - P0002281
Andrey Frolkin
2320 diagrammes 94 07-09/1990
1. Preis
P0002281
(14+16) C+
BP in 15,5
1. d3 d5 2. Le3 d4 3. Sd2 dxe3 4. Sb3 Dd4 5. Dd2 Ld7 6. 0-0-0 exd2+ 7. Kb1 De3 8. Tc1 d1=T 9. d4 Td3 10. Td1 Tc3 11. Td2 Tc6 12. Kc1 Td6 13. Kd1 Lc6 14. Ke1 Sd7 15. Td1 0-0-0 16. Ta1
play all play one stop play next play all
Henrik Juel: No solution in 15.0 or 14.5, so C++... (2018-12-8)
more ...
comment
Keywords: Unique Proof Game, Castling (wgsg), Castling Paradox (wg hidden), Non-standard material (t), Promoted material on the board (t)
Genre: Retro
Computer test: Natch 3.1 (28 min.)
Reprints: 88 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-12 more...
22 - P0002284
Andrey Frolkin
Kalininskaja Prawda 1988
Spezialpreis
P0002284
(14+13) C+
BP in19,5
1. Sf3 Sc6 2. Se5 Sd4 3. Sc6 dxc6 4. b4 Dd5 5. b5 Ld7 6. b6 0-0-0 7. bxa7 Le8 8. a8=S Kb8 9. Sb6 Ka7 10. Sd7 Ka6 11. Sxf8 Td7 12. Sg6 hxg6 13. c4 Th5 14. e4 Te5 15. Le2 f5 16. 0-0 Sf3+ 17. Kh1 Sg1 18. f3 Sf6 19. c5+ b5 20. cxb6ep+
play all play one stop play next play all
Henrik Juel: C+ by Natch 3.1
No solution in 18.5 or 17.5, so C++ (2018-12-8)
comment
Keywords: Unique Proof Game, En passant, Castling, Promotion (S), Valladao Task
Genre: Retro
Computer test: C+ by Natch 3.1
Reprints: 96 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-12 more...
23 - 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...
24 - P0002312
Kostas Prentos
5673 feenschach 93 11-12/1989
P0002312
(14+11)
BP in 17,5
1. e3 b5 2. Ld3 b4 3. Lg6 b3 4. axb3 hxg6 5. Ta5 Th3 6. Tb5 Tg3 7. hxg3 a5 8. Th8 a4 9. Dh5 a3 10. Se2 Ta4 11. bxa4 gxh5 12. b3 g6 13. Lb2 Lh6 14. Lg7 Lg5 15. Lh6 Lh4 16. gxh4 a2 17. Sg3 a1=T 18. Txg8#
play all play one stop play next play all
Henrik Juel: The content is concealed pawn captures
Despite no visible captures White captured a2xPb3xTa4 to open the a-line for [Ta1,Pa7], and h2xTg3xLh4 with black h7xLg6xDh5 to open the h-line for [Th1,Th8]
This makes life difficult for the human solver and for Natch 3.1, who tested the first 15.0 moves correct in 40 sec.
Testing the entire proof game would need more than a couple of hours by Natch (2018-12-8)
comment
Keywords: Unique Proof Game, Promotion (t)
Genre: Retro
Reprints: 143 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2014-11-7 more...
25 - P0002313
Yaakov Mintz
The Problemist 1987-1988
3.-5. ehrende Erwähnung e.a.
P0002313
(12+11) cooked
BP in 17,5
1. f3 e5 2. Kf2 e4 3. De1 e3+ 4. Kxe3 Ke7 5. Dg3 De8 6. Kf2 Kd8 7. Ke1 Lc5 8. Kd1 Lxg1 9. De1 Lxh2 10. Txh2 d6 11. Txh7 Le6 12. Txg7 Th1 13. Th7 Lxa2 14. Th8 Lxb1 15. Txa7 b5 16. Tb7 Ta1 17. Ta7 b4 18. Ta8
play all play one stop play next play all
Cook: NL
1. f3 e5 2. Kf2 e4 3. De1 e3+ 4. Kxe3 b5 5. Dg3 b4 6. Kf2 Lc5+ 7. Ke1 Lxg1 8. Kd1 Lxh2 9. Txh2 d6 10. Txh7 Le6 11. Txg7 Th1 12. Th7 Lxa2 13. Th8 Lxb1 14. Txa7 Ke7 15. Tb7 Ta1 16. Ta7 De8 17. Ta8 Kd8 18. De1 (Mario Richter)
paul: C+ (Euclide 1.11) for the first 13 moves (in about 51 hours). I do not dare to check for 13.5 moves. (2018-3-8)
Henrik Juel: Tiny typo in Mario's cook: 10.Txh7 (2018-3-8)
Mario Richter: The typo comes from a "by hand conversion" of the output of several tools I'm using (here: rawbats and chessbase) - unfortunately each tool has it's own output format, incl. the PDB solution field format ... (2018-3-9)
A.Buchanan: I have a janitor's tool which allows me to change the representation of positions & solutions.
Try to copy the file here: https://www.dropbox.com/sh/ld64s00zm0f9tx8/AAA7r8BsA0vuLcZOOKNvKkmua?dl=0
Click on it, and then hit the download button on the right.
The most useful is the one which converts from FEN to PDB "pieces" format.
Stick the input string in the yellow cell, and pick up the result from the green cell.
If you want to see how it's done, unhide the hidden rows and columns: no VBA just simple Excel.
Only 1% as clever as rawbats, but it still saves me a lot of time.
Feel free to use and to improve. (2018-3-9)
Mario Richter: @Andrew: Thanks for your offer - but I have such tools myself. My fault was not to use them (I thought that I'll be able to transform such a short PG by hand without errors ...)
Would be nice if the PDB-System would be more helpful with respect to language support.
I've decided to use 'english' in the language settings, but that doesn't help here, since solutions still have to be given in german piece notation.
Might be difficult to change this, especially when thinking of fairy piece names, so I can live with that, but there are other aspect which sometimes drive me crazy, e.g. the handling of source names in different languages ... (2018-3-9)
A.Buchanan: I thought you might have such a tool, but I thought it was a nice opportunity to announce it for others who might find it useful. (2018-3-9)
more ...
comment
Keywords: Unique Proof Game, Interchange, Belfort
Genre: Retro
Reprints: 144 Shortest Proof Games 11/1991
Best Problems 47 07/2008
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-12 more...
26 - P0002314
Valentin Balanovsky
Andrey Frolkin

Mat (Belgrad) 1985
P0002314
(11+14)
BP in 18,0
1. h4 d5 2. Th3 d4 3. Ta3 Lh3 4. Txa7 e6 5. a4 Ld6 6. Ta3 Lh2 7. Tf3 d3 8. Tf6 Dd4 9. f4 Dxb2 10. Kf2 Dxc1 11. Ke3 Dxd1 12. Kd4 Dxf1 13. Kc3 Dxg1 14. Kb2 De3 15. Kc1 Sd7 16. Kd1 0-0-0 17. Ke1 Kb8 18. Txb7+ Ka8
play all play one stop play next play all
Version A. Frolkin
Henrik Juel: Cooked by
1.Ba2-a4 Bd7-d5 2.Ta1-a3 Bd5-d4 3.Bh2-h4 Lc8-h3
4.Ta3-f3 Be7-e6 5.Tf3-f6 Lf8-d6 6.Sb1-a3 Ld6-h2
7.Bf2-f4 Bd4-d3 8.Ke1-f2 Dd8-d4 9.Kf2-f3 Dd4xg1
10.Dd1-e1 Dg1xf1 11.De1-f2 Df1xc1 12.Df2xa7 Dc1xb2
13.Kf3-f2 Db2-e5 14.Da7-e3 Sb8-d7 15.Th1-b1 O-O-O
16.Kf2-e1 Kc8-b8 17.Tb1xb7 Kb8-a8 18.Sa3-b1 De5xe3
with lots of variations (2018-12-6)
comment
Keywords: Unique Proof Game, Castling
Genre: Retro
Reprints: 145 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2006-1-10 more...
27 - P0002315
Jasper van Atten
Probleemblad 1985
4.-5. ehrende Erwähnung
P0002315
(16+15) C+
BP in 23,0
1. d4 g6 2. Kd2 Lg7 3. Ke3 Lf6 4. Kf4 Le5+ 5. Kg5 Sf6 6. Kh6 Lf4+ 7. Kg7 Lh6+ 8. Kxh8 Lf8 9. Lh6 Sg8 10. e3 f6 11. Dh5 Kf7 12. Sf3 Ke6 13. Lc4+ Kd6 14. Td1 De8 15. Td3 Df7 16. Ta3 Dd5 17. Sc3 Ke6 18. Ta6+ Kf7 19. a3 De6 20. Dc5 Ke8 21. Se5 Df7 22. Le6 Kd8 23. Sd5 De8
play all play one stop play next play all
Henrik Juel: C+ by Natch 3.1 (59 min.)
The content is given by the diagram position: Get wKe1 to h8 and interchange the black royals
Lf8 makes the roundtrip f8-g7-f6!-e5-f4-h6-f8
[Dd8] goes d8-e8-f7-d5-e6!-f7-e8
Resentful of the dissipation by some of his officers [Ke8] wastes no time going e8-f7-e6-d6-e6-f7-e8-d8 (2018-12-8)
comment
Keywords: Unique Proof Game
Genre: Retro
Computer test: Natch 3.1 (59 min.)
Reprints: 149 Shortest Proof Games 11/1991
Best Problems 47 07/2008
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-12 more...
28 - P0002318
Andrey Frolkin
The Problemist 1989
3. Preis
P0002318
(31+0) C+
Färbe die Steine!
BP in 17,5
1. e4 c5 2. Dg4 Da5 3. De6 fxe6 4. Ke2 Kf7 5. Kf3 Kf6 6. Kg4 Ke5 7. Kg5 h5 8. Kg6 Kf4 9. Kf7 Sh6+ 10. Ke8 Sf7 11. Lb5 Th6 12. d3+ Dd2 13. g4 a5 14. Sh3+ Kf3 15. g5 Ke2 16. Sg1+ Ke1 17. h3 Dd1 18. Sf3++
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Henrik Juel: The capture was fxDe
If White made it, Dd1 is white and so is Ke1, but he would stand in an illegal check from sPf2
So Dd1 and Ke1 are black (and Ke8 is white), and the rest of the men have a 'natural' color because of the shortish proof game, which is
C+ by Natch 3.1 (2 sec.) (2018-12-8)
comment
Keywords: Unique Proof Game, Coloring problem
Genre: Retro
Computer test: Natch 3.1 (2 sec.)
Reprints: 155 Shortest Proof Games 11/1991
feenschach 137 08-09/2000
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
29 - P0002319
Andrey Frolkin
Leonid Lyubashevsky

The Problemist 1988
1. Preis
P0002319
(30+0)
Färbe die Steine!
BP in 19,5
1. h4 h5 2. Th3 Th6 3. Tb3 Ta6 4. g3 g6 5. Lh3 Lh6 6. Le6 Le3 7. dxe3 dxe6 8. Ld2 Kd7 9. Lb4+ Kc6 10. Sc3 De8 11. Dd8 Sd7 12. 0-0-0 Sdf6 13. Kb1 Dd7 14. Ka1 Se8 15. Tb1 Dd1 16. Sd5 Kb5 17. Ld6+ Ka4 18. Tb6 Ld7 19. Sb4 Lb5 20. b3+
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Henrik Juel: The fastest captures are d2xLe3 and d7xLe6, so Lb5/Ld6 are black/white respectively
If Ka4 were white, so that Ka1,Tb1 would be black, more than 19 black moves would be needed
So Ka1, Tb1 (and Tb6) are white, needing white castling, which entails that Dd8 is white, because this saves a white move; then Dd1 and Ta6 are black, and the rest are 'naturally' colored, with Sb4/Se8 white/black
The colored position is C+ by Natch 3.1 (0.3 sec.)
The position after switching the colors of Sb4/Se8 cannot be reached in 19.5 moves (2018-12-8)
comment
Keywords: Unique Proof Game, Coloring problem, Castling
Genre: Retro
Reprints: 588 Ukrainisches Album 1986-1990
156 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2005-12-27 more...
30 - P0002320
Andrey Frolkin
Henri Nouguier

(8) diagrammes 92 01-03/1990
4. ehrende Erwähnung
P0002320
(31+0) C+
Bestimme die Art und Farbe der Steine für eine KBP!
1. h4 Sh6 2. Th3 Sf5 3. Te3 Sd4 4. Te6 dxe6 5. e3 Dd7 6. Lb5 Kd8 7. De2 De8 8. Ld7 Sbc6 9. Kd1 Tb8 10. De1
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Henrik Juel: The decoding is easy, with letters ABCDEF representing the men DKPLST; the coloring is natural, with Ld7 being white
The shortest proof game lasts 9.5 moves and is
C+ by Natch 3.1 (2018-12-8)
comment
Keywords: Letter problem, Unique Proof Game
Genre: Retro
Computer test: Natch 3.1
Reprints: 591 Ukrainisches Album 1986-1990
159 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
31 - P0002333
Jasper van Atten
The Problemist 1987-1988
3.-5. Ehrende Erwähnung
P0002333
(16+15) C+
BP in 19,0
1. e4 Sf6 2. Lc4 Sd5 3. d3 f6 4. Lf4 Kf7 5. Dh5+ Ke6 6. Se2 De8 7. 0-0 Dg6 8. Kh1 Dg3 9. De8 De3 10. fxe3 Sc6 11. Tf3 Se5 12. Th3 Kd6 13. Sg3 Sb4 14. Lf7 Kc6 15. c4 Sg4 16. Sc3 Sh6 17. Tg1 Sg8 18. Th6 Sa6 19. h3 Sb8
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more ...
comment
Keywords: Unique Proof Game, Interchange (ss), Castling
Genre: Retro
Computer test: Natch 3.1 (1 min.)
Reprints: 70 Shortest Proof Games 11/1991
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
32 - P0002373
Alexander Kislyak
Die Schwalbe 136 08/1992
P0002373
(12+7) C+
BP in 15,5
1. d3 Sh6 2. Lxh6 c5 3. Lxg7 c4 4. Lxf8 c3 5. Lxe7 cxb2 6. Lxd8 0-0 7. c4 Kh8 8. c5 Tg8 9. c6 Txg2 10. c7 Txh2 11. Lh3 d5 12. Lxc8 f5 13. Lxb7 f4 14. Lxa8 f3 15. Lxd5 fxe2 16. Lf6#
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more ...
comment
Keywords: Unique Proof Game, Castling
Genre: Retro
Computer test: Natch 3.1 (3 min.)
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
33 - P0002534
Dirk Borst
Markus Ott

FIDE Kongress 37 Belfort 07/1994
2. Preis
P0002534
(13+15) C+
BP in 15,0
1. h4 e5 2. Th3 Df6 3. Ta3 Lxa3 4. b3 Lxc1 5. Sc3 La3 6. Db1 Lf8 7. Kd1 Ke7 8. Kc1 Kd6 9. Kb2 Kc5 10. De1 Kb4 11. Kc1 Ka3 12. Kd1 Kb2 13. Sd5 La3 14. Se7 Kxa1 15. Sxg8 Lc1
play all play one stop play next play all
(note: location of BK is not thematic for Belfort Theme).
Henrik Juel: C+ by Natch 3.1 (9 hours)
The two Belfort officers are wSg8 and sLc1
Here is the added feature that [Lf8] goes to c1 (to capture wLc1), then back to f8 (to make room for [Dd1] and [Ke1] to interchange, while clearing the way for [Ke8]'s march to a1), and then to c1 a second time (2018-12-9)
more ...
comment
Keywords: Unique Proof Game, Belfort
Genre: Retro
Computer test: Natch 3.1 (9 hours)
Reprints: (24) diagrammes 110 07-09/1994
8 feenschach 114, p. 414, 12/1994
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
34 - P0002605
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002605
(7+1)
In welche Richtung ziehen die Bauern?
von oben nach unten
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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...
35 - 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+
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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...
36 - 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
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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...
37 - P0002608
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes 1979
P0002608
(12+14)
Auf welchem Feld wurde die wD geschlagen?
h6
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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...
38 - 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)
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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...
39 - 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!
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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...
40 - 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)
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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...
41 - 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...
42 - 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...
43 - P0002616
Raymond Smullyan
The Chess Mysteries of Sherlock Holmes , p. 49, 1979
P0002616
(9+9)
Welcher Stein steht auf a5?
(+wKa5)
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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...
44 - 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#
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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...
45 - 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...
46 - 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...
47 - 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
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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, Pawn endgame
Genre: Retro
Reprints: Schach mit Sherlock Holmes 1982
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-3 more...
48 - 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...
49 - 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
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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...
50 - 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
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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...
51 - 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
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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...
52 - 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...
53 - 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...
54 - 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...
55 - 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...
56 - 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...
57 - 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...
58 - 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...
59 - 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...
60 - 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...
61 - 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...
62 - 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...
63 - 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...
64 - 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...
65 - 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...
66 - 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...
67 - 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...
68 - 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...
69 - 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...
70 - 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...
71 - P0002795
Alexander Kislyak
32 Powerschennii Monarch 1993
P0002795
(9+13) C+
BP in 15,5
1. a4 Sc6 2. Ta3 Sd4 3. Tf3 Sxe2 4. Txf7 Sxc1 5. Txf8+ Kxf8 6. Lc4 De8 7. Lxg8 Txg8 8. f4 Kf7 9. Sf3 Ke6 10. 0-0 Kd5 11. c4+ Kxc4 12. Te1 Kd3 13. Te6 dxe6 14. De2+ Kxe2 15. a5 Sd3 16. Sc3#
play all play one stop play next play all
Henrik Juel: C+ by Natch 3.1 (57 min.)
The author made 64 proof games, all ending in Black being mated, on the 64 squares of the board
This is a neat model mate (2018-12-9)
comment
Keywords: Unique Proof Game, Castling
Genre: Retro
Computer test: Natch 3.1 (57 min.)
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
72 - P0003038
Luigi Ceriani
4338v The Fairy Chess Review 3 28/11/1939
T. R. Dawson zum 50. Geburtstag
P0003038
(16+16)
BP in 26,0
1. h4 h5 2. Th3 Th6 3. Tc3 Te6 4. e3 Te4 5. De2 e6 6. Da6 La3 7. Lc4 De7 8. d3 Db4 9. Sd2 d6 10. Sdf3 Sd7 11. Ld2 Sdf6 12. 0-0-0 Ld7 13. Tf1 0-0-0 14. Se1 Tf8 15. Sgf3 Se8 16. Th1 Sgf6 17. Th3 Th8 18. Tg3 Th6 19. Tg5 Tg6 20. Ta5 Tg3 21. Lb5 Th3 22. Tc6 Th1 23. Sh2 Tf1 24. f3 Tf2 25. Lc3 Td2 26. Kb1 Td1#
play all play one stop play next play all
corrected version by V. Onitiu
Henrik Juel: Natch 3.1 did find a strategy, but otherwise nothing happened in more than an hour (2018-12-6)
comment
Keywords: Unique Proof Game, Castling, Capture-free
Genre: Retro
Reprints: The Fairy Chess Review 08/1940
147 La Genesi delle Posizioni 1961
Input: Gerd Wilts, 1995-6-3
Last update: A.Buchanan, 2014-5-22 more...
73 - P0003049
Raymond Smullyan
The Chess Mysteries of the Arabian Knights 1981
P0003049
(14+15)
Ein sL hat einen weißen Stein geschlagen. Welcher sL?

Der sLe5 hat den wL geschlagen.
Alfred Pfeiffer: Falsche Lösung. Richtige Antwort ist: sLe5 hat wL geschlagen. (2010-7-27)
Henrik Juel: Alfred is right, so please correct the official solution
The capture sequence must have been
g7xSh6 before d2xTc3 before Lx[Lc1] (2019-1-23)
comment

Genre: Retro
Reprints: Die Schachgeheimnisse des Kalifen , p. 10, 1984
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2019-1-23 more...
74 - P0003050
Raymond Smullyan
The Chess Mysteries of the Arabian Knights 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, 2019-1-23 more...
75 - 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...
76 - 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...
77 - 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...
78 - P0004176
Leon Loewenton
(IV) Problem 33-36 02/1956
P0004176
(9+8) cooked
BP in 16,0
1. a4 Sf6 2. a5 Sd5 3. Ta4 Sb6 4. axb6 h5 5. bxc7 h4 6. cxd8=L h3 7. Lxe7 hxg2 8. Lxf8 gxh1=L 9. Lxg7 Lg2 10. Lxh8 Lxf1 11. Le5 Lxe2 12. Lxb8 Lxd1 13. Lg3 Lxc2 14. f4 Lxb1 15. Kf2 Lg6 16. Te4+ Kf8
play all play one stop play next play all
Cook: NL
1. a4 h5 2. a5 Th6 3. Ta4 Tb6 4. axb6 Sf6 5. bxc7 h4 6. cxd8=L h3 7. Lxe7 hxg2 8. Lxf6 gxh1=L 9. Lxg7 Lg2 10. Lxf8 Lxf1 11. Ld6 Lxe2 12. Lxb8 Lxd1 13. Lg3 Lxc2 14. f4 Lxb1 15. Kf2 Lg6 16. Te4+ Kf8
Henrik Juel: Jacobi got nowhere in more than an hour (2018-12-6)
Mario Richter: Cook found by rawbats:
1. a4 h5 2. a5 Th6 3. Ta4 Tb6 4. axb6 Sf6 5. bxc7 h4 6. cxd8=L h3 7. Lxe7 hxg2 8. Lxf6 gxh1=L 9. Lxg7 Lg2 10. Lxf8 Lxf1 11. Ld6 Lxe2 12. Lxb8 Lxd1 13. Lg3 Lxc2 14. f4 Lxb1 15. Kf2 Lg6 16. Te4+ Kf8 (2018-12-7)
Henrik Juel: Thanks for bringing your versatile program out, Mario
I was pretty sure that this proof game must be cooked, but could not show it by my own tools (2018-12-7)
comment
Keywords: Unique Proof Game, Promotion, under-promotion (L l), Promoted material on the board (wLg3 sLg6)
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-7 more...
79 - P0004263
George A. Teodoru
(11) Problem 52-54 08/1958
Lob
P0004263
(11+10)
BP in 19,0
1. a4 Sf6 2. a5 Sd5 3. Ta4 Sb6 4. axb6 Sc6 5. bxa7 Tb8 6. axb8=S Se5 7. Sxd7 c6 8. Sxf8 Lg4 9. Sxh7 Lxe2 10. Sg5 Lxf1 11. Se4 Le2 12. Sec3 Lxd1 13. Sa2 Lxc2 14. Ke2 Lf5 15. Ke3 Th3+ 16. Kf4 Ta3 17. Kg5 Lh3 18. Tg4 Ta8 19. Sa3 Kf8
play all play one stop play next play all
Henrik Juel: The given solution implies that wSg1 is missing in diagram
With this added, there are lots of cooks, e.g.
1.Sb1-c3 Sb8-c6 2.Ba2-a4 Ta8-b8 3.Ba4-a5 Sg8-f6
4.Ta1-a4 Sf6-d5 5.Sc3-a2 Sd5-b6 6.Ba5xb6 Bd7-d5
7.Bb6xa7 Bd5-d4 8.Ba7-a8=S Bd4-d3 9.Sa8-b6 Bd3xe2
10.Sb6-c4 Be2xf1=S 11.Ke1-e2 Tb8-a8 12.Ke2-f3 Sc6-e5
13.Kf3-f4 Sf1-e3 14.Kf4-g5 Bh7-h5 15.Dd1xh5 Se3xc2
16.Dh5xh8 Sc2-a3 17.Dh8xf8 Ke8xf8 18.Sc4xa3 Lc8-h3
19.Ta4-g4 Bc7-c6
With the given diagram position, the problem is also badly cooked (2018-12-6)
comment
Keywords: Unique Proof Game, Interchange
Genre: Retro
Input: Gerd Wilts, 1995-6-3
Last update: Gerd Wilts, 2006-1-10 more...
80 - 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...
81 - P0004367
Andrey Frolkin
560 Europe Echecs 403 07-08/1992
P0004367
(10+12) cooked
KBP
a) Weiß am Zug
b) Schwarz am Zug
a) 1. e4 h5 2. Dxh5 Txh5 3. h3 Txh3 4. a3 Txa3 5. Txa3 a6 6. Txa6 Sf6 7. Txf6 gxf6 8. Th6 Lxh6 9. d3 Lxc1
b) 1. d3 h6 2. Lxh6 Txh6 3. h4 Txh4 4. a4 Txa4 5. Txa4 a6 6. Txa6 Sf6 7. Txf6 gxf6 8. Th6 Lxh6 9. Dc1 Lxc1 10. e4
play all play one stop play next play all
Cook: Duale
a) 1. e4 h5 2. Dxh5 Txh5 3. h3 Txh3 4. a3 Txa3 5. Txa3 a6 6. Txa6 Sh6! 7. Tf6 gxf6 8. Txh6 Lxh6 9. d3 Lxc1
b) 1. d3 h6 2. Lxh6 Txh6 3. h4 Txh4 4. a4 Txa4 5. Txa4 a6 6. Txa6 Sh6! 7. Tf6 gxf6 8. Txh6 Lxh6 9. Dc1 Lxc1 10. e4
paul: Dual: a) 6.- Sh6! 7.Tf6 gxf6 8.Txh6 Lxh6 9.d3 Lxc1. (2010-7-30)
Henrik Juel: Part b) is also ruined, by the same dual (2018-12-9)
Henrik Juel: ... almost the same, namely
6... Sh6 7.Tf6 gxf6 8.Txh6 Lxh6 9.Dc1 Lxc1 10.e4 (2018-12-9)
comment
Keywords: Unique Proof Game
Genre: Retro
Reprints: (12) diagrammes 15 07-09/1994
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-10 more...
82 - 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...
83 - P0005301
Ludwig Zagler
3673 Problemkiste 98 04/1995
P0005301
(1+2)
-1(w+s), dann h#1
Anticirce
R: 1. Ka7-a8 Lc7xDe5[+sLf8], dann 1. Kd8 De8#
play all play one stop play next play all
Gerald Ettl: Wichtig Typ Calvet. Nicht schlecht. (2009-2-10)
Alfred Pfeiffer: Beim Typ Calvet sind Schläge auf das eigene Wiedergeburtsfeld erlaubt. Wäre deshalb hier nicht der Typ Cheylan zu fordern, um 2. Kxe8 auszuschließen ? (2018-12-6)
Henrik Juel: You are right, Alfred (2018-12-7)
Gerald Ettl: ja das stimmt. (2018-12-7)
comment
Keywords: Circe (Anti-), Help retractor, Aristocrat, Rex solus (w)
Genre: Retro, Fairies
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-6 more...
84 - P0005325
Michel Caillaud
13 Rex Multiplex 1 01-03/1982
3. ehrende Erwähung
P0005325
(12+8)
#2
b) wKa4 nach a3
a) 1. Dd6? Th4!
1. Sc6! droht 2. Dd8# (1. ... 0-0?? illegal)

b) 1. Sc6? 0-0!
1. Dd6! droht 2. Lb5#
R: 1. g6-g5 Kb3xBa3 2. h7xTg6 Kc3xBb3 3. a4-a3 Kd3xBc3 4. a5-a4 Ke3xBd3 5. a6-a5 Dd5-d4 6. b4-b3 Dg2-d5 7. b5-b4 Df1-g2 8. b6-b5 Dd1-f1 9. b7-b6 Kf3-e3 10. d4-d3 Kg2-f3 11. d5-d4 Kf1-g2 12. d6-d5 Ld5-c4 13. c4-c3 Ke1-f1 14. c5-c4 Lg2-d5 15. c6-c5 Lf1-g2 16. c7-c6 g2-g3 17. Sg3-h1
play all play one stop play next play all
In a) fehlt ein Tempo zur Auflösung.
Schlagfälle: hxgxfxexd, e7xf6, h7xg6, wLc1, wTa1 auf a1, b1 oder c1.
Renny Bosch: The answer given as "a) 1. Sc3 0. 0?" was probably intended to be "a) 1. Sc6 0-0 2. ?", implying that in a) B may still have castling rights. But regardless of B's castling right, 1. Qd6 ... 2. Bb5# works in either case. Clearly there must be a reason why that is impossible in one of the two cases.

Most likely there is a misprint in the given position: wBc4 should be at b3. Then 1. Qd6 ... 2. Bc4# works in b) but not in a). And in a), the retro play shows that B can no longer castle, because he has to make a move after wKa4.

Also, the retro play as given leads to an initial position which is illegal, because with bPs at c7, d6, f6 and g7, the wB created on d8 would not be able to get out. And if the bPd6 were still at d7, then the bBc8 would not have been able to get captured by the wPh2. So bPb7 must already be at b6.

Here is a PG for a) that preserves B's castling right as long as possible, but in the end must lose it, leading to the #2.

1. Nc3 Nf6 2. Nb5 Ng4 3. h3 a6 4. hxg4 b6 5. Rh6 Bb7 6. Rf6 Be4 7. Nf3 Bf5 8. gxf5 exf6 9. Nh4 Qe7 10. Ng6 Qe6 11. fxe6 Nc6 12. e7 Rd8 13. exd8=B Bd6 14. Be7 Bh2 15. Bd6 Bg1 16. Bh2 Nd4 17. Na7 Nb3 18. Nb5 Nxa1 19. Na7 Nb3 20. Nb5 Nxc1 21. Na7 Nb3 22. Nb5 Nd4 23. Na7 Nf5 24. Nb5 Ng3 25. Na7 Nh1 26. g3 d6 27. Bh3 d5 28. Be6 d4 29. Kf1 d3 30. Kg2 c6 31. Kf3 c5 32. Ke3 c4 33. Qf1 c3 34. Qg2 b5 35. Qe4 b4 36. Qd4 b3 37. Kxd3 a5 38. Kxc3 a4 39. Kb4 a3 40. Kxa3 hxg6 41. Bxb3 g5 42. Kb4 Rg8 43. Ka4 Rh8 {the given position} 44. Nc6 Rg8 45. Qd8# (2008-5-16)
Michel Caillaud: in a), 1.Qd6? ~ 2.Lb5# doesn't work because of 1...Rh4! (2008-5-19)
Henrik Juel: Typos in the solution for part a)
Here are the correct solutions and tries:
a) 1.Sc6 thr. 2.Dd8# (1... 0-0?? is illegal), not 1.Dd6? Th4!
b) 1.Dd6 thr. 2.Lb5#, not 1.Sc6? 0-0!

Very elegant twinning (2018-12-4)
Henrik Juel: Thanks for your update, Alfred
There still are errors in the given retroplay
The black b-pawn should retract to b6 only, and the d-pawn all the way to d7
Then e7xTd8=L can be retracted, and [Lc8] is not locked out (2018-12-4)
comment
Keywords: Castling, Promotion
Genre: Retro
Reprints: B 64 Proof Games 2012
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-4 more...
85 - P0005393
Alexander Kislyak
38 Shakhmatnaya Kompozitsiya 04/1993
P0005393
(11+13) C+
BP in 16,0
1. e4 a5 2. De2 Ta6 3. Dxa6 a4 4. Dg6 hxg6 5. h3 Txh3 6. e5 Ta3 7. e6 Txa2 8. exd7+ Lxd7 9. Th3 e6 10. Ta3 Lb4 11. Sf3 Lc3 12. dxc3 Df6 13. Lg5 Se7 14. Lh4 g5 15. c4 Dg6 16. Sc3 Txa1+
play all play one stop play next play all
more ...
comment
Keywords: Unique Proof Game
Genre: Retro
Computer test: Natch 3.1 (1 hour 40 min.)
Input: Gerd Wilts, 1995-6-3
Last update: Alfred Pfeiffer, 2018-12-13 more...
86 - P0005598
Jorge Abel Barros
Raul Ocampo
C. Buchborn
Alfred Gschwend
Josef Haas
Hans Hofmann
G. Jensen
Karl Kaul
Jorge Joaquin Lois
Julio Alberto Pancaldo
Pedro Gomez Masia
Emiliano F. Ruth
Helmut Mertes
John Niemann
Hector G. Zucal
Horacio Amil Meylan

(3) Die Schwalbe 25 02/1974
P0005598
(5+0)
51 gedeckte Felder
Konstruktionsausschreiben 06/1973
A.Buchanan: Is this (16) the maximum number of composers for a problem? Sublime! (2019-1-1)
comment
Keywords: Construction task
Genre: Retro
Input: Gerd Wilts, 1995-6-5
87 - P0005787
Andrey Frolkin
Leonid Lyubashevsky

Zaporizka pravda 1988
Spezialpreis
P0005787
(26+0) C+
Färbe die Steine!
KBP?
1. Sa3 d5 2. Sc4 Lg4 3. Se5 Lf3 4. Sg6 hxg6 5. gxf3 Th3 6. f4 Tg3 7. Lh3 c6 8. Lc8 e6 9. hxg3 Lb4 10. Th8 Lc3 11. bxc3 Ke7 12. La3+ Kf6 13. Db1 Sh6 14. Db6 axb6 15. Lf8 Ta3 16. Sh3 Tb3 17. axb3 Dd6 18. Ta8 Sa6
play all play one stop play next play all
Henrik Juel: The fastest pawn captures are a2xb3, b2xc3, g2xf3, h2xg3, and a7xb6, h7xg6
Surprisingly, in the intended coloring, the four men on row 8 are white; the rest is 'normal' (2018-12-9)
Henrik Juel: The colored position is C+ by Natch 3.1 (1 sec.)
No solution in 17.5 or 17.0 moves (2018-12-9)
comment
Keywords: Unique Proof Game, Coloring problem
Genre: Retro
Computer test: Natch 3.1 (1 sec.)
Reprints: 586 Ukrainisches Album 1986-1990
(4) Die Schwalbe 144 12/1993
Input: Gerd Wilts, 1995-6-7
Last update: Alfred Pfeiffer, 2018-12-13 more...
88 - P0005845
Unto Heinonen
U.S. Problem Bulletin 1993
1. Preis
P0005845
(16+16) C+
BP in 21,5
1. d4 h5 2. Lh6 Sf6 3. f4 Se4 4. Sf3 Sd2 5. e4 a5 6. La6 e5 7. c4 Lb4 8. Da4 c5 9. Dc6 b5 10. Lb7 Ta6 11. a4 Tb6 12. Sa3 Sa6 13. 0-0-0 Sf1 14. Td3 Le1 15. b4 Dh4 16. Tb3 Df2 17. h4 Kd8 18. Th3 d5 19. Tg3 Lh3 20. Tg6 f5 21. Tf6 g5 22. g4
play all play one stop play next play all
more ...
comment
Keywords: Unique Proof Game, Castling, Ornament, Capture-free
Genre: Retro
Computer test: Natch 3.1 (1 min.)
Reprints: feenschach 121, p. 311, 11/1996
H28 FIDE Album 1992-1994 2001
feenschach 141 06/2001
Input: Gerd Wilts, 1995-6-20
Last update: Alfred Pfeiffer, 2018-12-13 more...
89 - P0005880
Michel Caillaud
R222v The Problemist 01/1994
Ladislav Packa gewidmet
P0005880
(12+14) C+
BP in 29,0
1. h4 a5 2. h5 a4 3. h6 a3 4. hxg7 axb2 5. Th6 bxa1=T 6. Tc6 h5 7. Sh3 h4 8. Sf4 h3 9. Sd5 h2 10. f4 h1=T 11. Kf2 Txf1 12. Kg3 Thh1 13. a4 Sh6 14. g8=L dxc6 15. Lh7 Sd7 16. Lf5 Sb6 17. Lh3 Lf5 18. a5 e6 19. a6 Lc5 20. a7 Le3 21. dxe3 Dd6 22. Dd3 Kd7 23. Ld2 Th8 24. a8=D Lh7 25. Dg8 Ta8 26. Dgg6 Kc8 27. La5 Kb8 28. Sbc3 Ta1 29. Kh4 Dd8
play all play one stop play next play all
Henrik Juel: C+ by Natch 3.1 (21 min.)
A fantastic idea: By move 10 Black has promoted on a1,h1, so he has rooks in all four corners; during the next 18 moves the rooks interchange cyclically clockwise, motivated by the need for white to play a8=D-g8-g6
This leaves an ugly promoted wD on the board, whereas the promoted wLh3 is more discrete; maybe the author had a8=T in the first version, which was then cooked (2018-12-9)
comment
Keywords: Unique Proof Game, Non-standard material, Platzwechsel, zyklischer (tttt), Promoted material on the board (L), Four corners
Genre: Retro
Computer test: Natch 3.1 (21 min.)
Reprints: H32 FIDE Album 1992-1994 2001
(1) Quartz 18 10-12/2002
Input: Gerd Wilts, 1995-6-26
Last update: Alfred Pfeiffer, 2018-12-13 more...
90 - P0005887
Valentin Balanovsky
4607 Mat (Belgrad) 07-08/1985
P0005887
(15+12) cooked
BP in 17,0
1. a4 h5 2. Ta3 h4 3. Tg3 hxg3 4. h4 Th6 5. h5 Tf6 6. h6 Tf3 7. h7 Sf6 8. Th6 Sh5 9. c4 f6 10. Db3 Kf7 11. Dxb7 Ke6 12. Dxc8 Kd6 13. Dxd8 Kc6 14. Dxf8 Kb7 15. Df7 Kc8 16. c5 Kd8 17. Da2 Ke8
play all play one stop play next play all
Cook: 1. c4 h6 2. Db3 h5 3. Dxb7 Th6 4. Dxc8 Tb6 5. c5 h4 6. a4 Sf6 7. Ta3 Sd5 8. Tg3 hxg3 9. h4 f6 10. Dxd8 Kf7 11. Dxf8 Kg6 12. Dg8 Sf4 13. Da2 Tb3 14. h5 Kf7 15. h6 Ke8 16. h7 Tf3 17. Th6 Sh5
Autorangabe: V. Z. Balanovskij SSSR,
Forderung: "Shortest game?" (kein Zusatz "2 Lösungen", und die mit 1. c4 beginnende BP ist explizit als NL gekennzeichnet).
Henrik Juel: Natch 3.1 found thousands of solutions, so badly cooked, regardless of the number of solutions stipulated (unless this number is 8605, but that would be silly) (2018-12-6)
comment
Keywords: Unique Proof Game, Pure Round Trip (k)
Genre: Retro
Input: Gerd Wilts, 1995-6-26
Last update: Mario Richter, 2018-12-7 more...
91 - P0005903
Jasper van Atten
R195 The Problemist 09/1993
P0005903
(14+15) C+
BP in 20,0
1. d3 a5 2. Le3 Ta6 3. La7 h5 4. e3 h4 5. Dh5 Tah6 6. Le2 T6h7 7. Dh6 b6 8. Lh5 Lb7 9. Ke2 La6 10. Kf3 a4 11. Se2 a3 12. Sxa3 h3 13. Tag1 hxg2 14. Sc1 gxh1=S 15. Tg4 Sf6 16. Tb4 Tg8 17. Sc4 Thh8 18. a3 Sh7 19. Ke4 Lc8 20. f3 Sa6
play all play one stop play next play all
more ...
comment
Keywords: Unique Proof Game, Loss of tempo (l3), Promotion
Genre: Retro
Computer test: Natch 3.1 (7 sec.)
Input: Gerd Wilts, 1995-6-26
Last update: Alfred Pfeiffer, 2018-12-13 more...
92 - P0005936
Nikita M. Plaksin
2999 feenschach 49 01-03/1980
2. Lob
P0005936
(11+14)
BP in 28,0
1. h4 a5 2. h5 a4 3. h6 Ta5 4. hxg7 h5 5. g4 Sh6 6. g8=L! Lg7 7. g5 Sc6 8. g6 Tg5 9. Th2 Le5 10. g7 f6 11. Lb3 axb3! 12. g8=L! b5 13. Lc4 d5 14. a4 dxc4! 15. a5 Dd3 16. a6 Dg3 17. e3 Sb4 18. Le2 Sa2 19. Kf1 Sxc1 20. f4 Sa2 21. fxg5 Lb7 22. g6 Lh1 23. g7 c3 24. g8=L! h4 25. Lc4 bxc4! 26. a7 Sg8 27. a8=L! h3 28. Lg2 hxg2!
play all play one stop play next play all
Henrik Juel: The moves edified by an exclamation mark are not particularly good or surprising
The marks just highlight the four white promotions to L and the black pawn captures getting rid of them (2018-12-6)
Henrik Juel: Many cooks, e.g.
1.Bg2-g4 Sb8-c6 2.Bh2-h4 Ba7-a5 3.Bh4-h5 Ba5-a4
4.Bh5-h6 Ta8-a5 5.Bh6xg7 Bh7-h5 6.Bg4-g5 Sg8-h6
7.Bg5-g6 Ta5-g5 8.Bg7-g8=L Lf8-g7 9.Th1-h2 Lg7-e5
10.Bg6-g7 Bf7-f6 11.Lg8-b3 Sc6-b4 12.Bg7-g8=L Ba4xb3
13.Ba2-a4 Sb4-a2 14.Lg8-c4 Bd7-d5 15.Ba4-a5 Bd5xc4
16.Ba5-a6 Dd8-d3 17.Ba6-a7 Dd3-g3 18.Be2-e3 Sa2xc1
19.Lf1-e2 Sc1-a2 20.Ke1-f1 Bb7-b5 21.Bf2-f4 Lc8-b7
22.Bf4xg5 Lb7-h1 23.Bg5-g6 Bc4-c3 24.Bg6-g7 Bh5-h4
25.Bg7-g8=L Bh4-h3 26.Lg8-c4 Sh6-g8 27.Ba7-a8=L Bb5xc4
28.La8-g2 Bh3xg2 (2018-12-6)
comment
Keywords: Unique Proof Game, Ceriani-Frolkin Theme
Genre: Retro
Input: Gerd Wilts, 1995-6-26
Last update: A.Buchanan, 2012-4-8 more...
93 - P0005946
Yis Yoront
5508 feenschach 91 05-08/1989
P0005946
(16+15) C+
KBP, dann #1 (wer?)
1. h4 g5 2. hxg5 d6 3. Th4 Lh3 4. g4 Dd7 5. Lg2 Db5 6. Lc6+ Sd7 7. e4 0-0-0 8. Df3 Kb8 9. Db3 Dd3, dann 10. Dxb7#
play all play one stop play next play all
FJS: "Einfaches Auszählen ergibt, daß beide Parteien schon mindestens 9 Züge gemacht haben. Eine 9-zügige Beweispartie ist leicht zu finden: "1.h4 g5 2.hxg5 d6 3.Th4 Lh3 4.g4 Dd7 5.Lg2 Db5 6.Lc6+ Sd7 7.e4 000 8.Df3 Kb8 9.Db3 Dd3, also ist Weiß am Zug: 10.Dxb7#
JV: "Ich würde sagen: Das ist eine Aufgabe für Retro-Unerfahrene." Retro für alle, wie GL das in der Schwalbe nennt. [2,6/II]
more ...
comment
Keywords: Unique Proof Game, Castling
Genre: Retro
Computer test: Natch 3.1
Input: Gerd Wilts, 1995-6-26
Last update: Alfred Pfeiffer, 2018-12-13 more...
94 - P0005949
Andrey Frolkin
Gerd Wilts
Alexander Kislyak

unveröffentlicht?
P0005949
(11+13)
a) BP in 15,5
b) -4 Züge, dann BP in 13,0
a) 1. a4 h5 2. a5 Th6 3. a6 Txa6 4. Txa6 bxa6 5. b4 Lb7 6. b5 Le4 7. b6 Lh7 8. e4 cxb6 9. Lxa6 Dc7 10. De2 Dxh2 11. Df1 Dxg1 12. Dxg1 f5 13. Df1 Kf7 14. Db5 Kg6 15. 0-0 Kh6 16. d3+
b) 1. a4 h5 2. a5 Th6 3. a6 Txa6 4. Txa6 bxa6 5. b4 Lb7 6. b5 Le4 7. b6 Lh7 8. e4 cxb6 9. Lxa6 Dc7 10. De2 Dxh2 11. Db5 Dxg1 12. Txg1 f5 13. Th1 Kf7
play all play one stop play next play all
Henrik Juel: Paradoxical twins
a) needs 31 single moves, but the position obtained after 27 single moves can be reached from the initial array in just 26 single moves, as shown in b)
There is no real paradox of course, in a) you must use an extra white move to preserve the castling right
Gerd may know the reason for not publishing, maybe it is because the first 20 single moves are identical in the twins (2018-12-6)
comment
Keywords: Unique Proof Game, Castling
Genre: Retro
Input: Gerd Wilts, 1995-6-26
Last update: Gerd Wilts, 2004-8-11 more...
95 - P0006245
Peter Wong
2024 Phénix 31 07/1995
1. Preis
P0006245
(12+15) C+
BP in 27,5
1. Sf3 a6 2. Sd4 Ta7! 3. Sb5 axb5 4. f3! Ta3 5. bxa3 Sc6 6. Lb2 Sa5 7. Le5 Sc4 8. Ld6 cxd6 9. c3 Da5 10. Dc2 Da4 11. Dg6 Dc2 12. Dh6 gxh6 13. f4 Lg7 14. f5 Ld4 15. f6 Sxf6 16. h3! Tg8 17. h4 Tg3 18. h5 Th3 19. g3! La7 20. Lg2 b6 21. La8 Lb7 22. 0-0 Lg2 23. Lf3 Se4 24. g4 f6 25. g5 Kf7 26. g6 Ke6 27. g7 Kd5 28. g8=S
play all play one stop play next play all
more ...
comment
Keywords: Bahnung, Räumung, Unique Proof Game, Castling, Loss of tempo (t1), Promotion
Genre: Retro
Computer test: Natch 3.1 (2 min.)
Reprints: 3402 U.S. Problem Bulletin 102/103 07-10/1995
H17 FIDE Album Annexe 1995-1997 2004
(66) Parallel Strategy 2004
Input: Gerd Wilts, 1995-8-17
Last update: Alfred Pfeiffer, 2018-12-13 more...
96 - P0006428
Andrey Frolkin
9133v Die Schwalbe 157, p. 283, 02/1996
P0006428
(13+12) cooked
BP in 20,0
May White castle?
Weiß darf noch rochieren: 1. h4 Sa6 2. h5 Sc5 3. h6 a6 4. hxg7 h5 5. f4 h4 6. f5 h3 7. f6 h2 8. fxe7 Sf6 9. g8=L Lh6 10. Lxf7 Kxf7 11. e8=T Kg6 12. Te6 Dg8 13. Tc6 Db3 14. axb3 dxc6 15. Ta4 Lh3 16. Te4 Tag8 17. Te8 hxg1=D 18. e4 Dd4 19. Lc4 Tg7 20. Lg8 Dd8
Ohne die Bedingung, daß Weiß rochieren darf, gibt es andere BPs: 1. f4 Sa6 2. f5 Sc5 3. f6 a6 4. fxe7 f5 5. e4 f4 6. Lb5 f3 7. Lc6 f2+ 8. Ke2 fxg1=D 9. h4 dxc6 10. h5 Lf5 11. h6 Sf6 12. hxg7 Dd5 13. g8=L Db3 14. Lxh7 Kf7 15. axb3 Lh6 16. Ta4 Tag8 17. Td4 Dxd4 18. e8=T Tg7 19. Lg8+ Kg6 20. Ke1 Dd8
play all play one stop play next play all
SH: Cooked?:
1. e4 f5 2. Ne2 f4 3. h4 f3 4. h5 fxe2 5. f4 exf1B 6. f5 Bc4 7. f6 Bb3 8. axb3 Na6 9. fxe7 Nc5 10. Ra6 Nf6 11. Rc6 dxc6 12. h6 Bh3 13. hxg7 Qd7 14. g8B Bh6 15. Bxh7 Kf7 16. Qf3 Rag8 17. Qe2 Rg7 18. Bg8+ Kg6 19. Qd1 a6 20. e8R Qd8 (2005-6-20)
Henrik Juel: The stipulation question was probably intended as an implicit condition; when answered affirmatively, there should be a unique solution
But SH's solution shows that the problem is cooked (2018-12-9)
comment
Keywords: Anti-Pronkin Theme, Conditional problem, Unique Proof Game, Castling in the forward play
Genre: Retro
Input: Gerd Wilts, 1996-6-12
Last update: Alfred Pfeiffer, 2018-12-13 more...
97 - P0006438
Andrey Frolkin
9191 Die Schwalbe 158, p. 343, 04/1996
Werner Keym gewidmet
2. ehrende Erwähnung Abt. II
P0006438
(15+15)
KBP?
UWF in der Diagrammstellung sind
1) zulässig
2) nicht zulässig
1) 1. h4 h5 2. Th3 Th6 3. Te3 Tc6 4. Te6 dxe6 5. a4 Dd5 6. a5 Kd7 7. a6 Kd6 8. axb7 a5 9. Sh3 Sa6 10. b8=T a4 11. Tb7 Tb8 12. Ta7 Lb7
2) 1. a4 h5 2. a5 Th6 3. a6 Tc6 4. axb7 a5 5. h4 Sa6 6. b8=D a4 7. Db3 Tb8 8. De6 dxe6 9. Th3 Dd5 10. Tb3 Kd7 11. Tb7 Kd6 12. Ta7 Lb7 13. Sh3
play all play one stop play next play all
Henrik Juel: Part 1) is C+ by Natch 3.1 (2018-12-9)
comment
Keywords: Ceriani-Frolkin Theme (D), Unique Proof Game, Promotion
Genre: Retro
Input: Gerd Wilts, 1996-6-12
Last update: Alfred Pfeiffer, 2018-12-13 more...
98 - P0006626
Andrey Frolkin
(56v) Die Schwalbe 159, p. 362, 06/1996
1. ehrende Erwähnung
Ceriani-Gedenkturnier, 1. Abteilung
P0006626
(13+12) cooked
BP in 20,0
(21. 0-0 is possible)
1. h4 Sa6 2. h5 Sc5 3. h6 a6 4. hxg7 h5 5. f4 h4 6. f5 h3 7. f6 h2 8. fxe7 Sf6 9. g8=L Lg7 10. Lxf7 Kxf7 11. e8=T Kg6 12. Te6 Dg8 13. Tc6 Db3 14. axb3 dxc6 15. Ta4 Lg4 16. Te4 Taf8 17. Te8 hxg1=D 18. e4 Dd4 19. Lc4 Dd8 20. Lg8 Tf7
play all play one stop play next play all
Cook: NL
1. e4 f5 2. Se2 f4 3. h4 f3 4. h5 fxe2 5. f4 exf1=L 6. f5 Lc4 7. f6 Lb3 8. axb3 Sa6 9. fxe7 Sc5 10. Ta6 Sf6 11. Tc6 dxc6 12. h6 Lh3 13. hxg7 Dd7 14. g8=L Lg7 15. Lxh7 Kf7 16. Df3 Taf8 17. Lg8+ Kg6 18. De2 Tf7 19. Dd1 a6 20. e8=T Dd8 (Henrik Juel)
more ...
comment
Keywords: Unique Proof Game, Castling
Genre: Retro
Input: Gerd Wilts, 1996-7-11
Last update: Alfred Pfeiffer, 2018-12-13 more...
99 - P0007032
Henrik Juel
3000 Probleemblad 05/1996
P0007032
(15+16) C+
BP in 19,0
1. c3 h5 2. Dc2 Th6 3. Dh7 f5 4. Kd1 Kf7 5. Kc2 Ke6 6. Kd3 Kd5 7. Ke3 Kc4 8. a3 Kb3 9. Sh3 Kc2 10. Sf4 Kd1 11. h3 Ke1 12. Th2 Kxf1 13. Kf3 Ke1 14. Kg3 Kd1 15. Th1+ Kc2 16. Kh2 Td6 17. Kg1 Td5 18. Kf1 d6 19. Ke1 Le6
play all play one stop play next play all
Henrik Juel: C+ by Jacobi using the constraints
Ke8-c2-d1-e1xf1-e1-d1-c2 Ke1-d1-c2-d3-g3-h2-g1-f1-e1
which are valid, because [Ke8] is the only black man who could capture [Lf1] in time, so [Ke1] would have to get out via c2-d3 and back home via g3-h2
It is recommended that HC+ is used, but this is not available on the PDB (yet)
Ke1 made a round trip (which is stronger than a promenade) (2018-12-9)
comment
Keywords: Unique Proof Game, Promenade (Kk), Pure Round Trip (K)
Genre: Retro
Computer test: Jacobi
Reprints: Ex2 64 Proof Games 2012
Input: Gerd Wilts, 1996-8-12
Last update: Alfred Pfeiffer, 2018-12-13 more...
100 - P0008413
Guus Rol
Harry Goldsteen

Probleemblad 1 01-02/1989
P0008413
(8+12)
#2 durch Schwarz
1. Kxc2 Sb3 2. ... Tc1#
R: 1. ... Ta2-a1+ 2. a3xLb4 Lf8-b4 3. Lb4-c3 Kb3-a4 4. Le7-b4 a7xSb6 5. Sa4-b6 Dd5-d4 6. Sc3-a4 Dd4-d5 7. Sb1-c3 Ta1-a2 8. Lf6-e7 Kb4-b3 9. a2-a3+ Kc5-b4 10. Lg5-f6 Kd6-c5 11. Lf6-g5 Kd7-d6 12. Le7-f6 Kc8-d7 13. Lf6-e7 Kb8-c8 14. Ld8-f6 e7-e6 15. d7-d8=L Kc8-b8 16. e6xTd7+ Td8-d7 17. f5xLe6 0-0-0 18. f4-f5 Lc8-e6 19. f3-f4 Dd8-d4 20. f2-f3 d7xLc6 21. Lf3-c6 Sc6-a5 etc.
play all play one stop play next play all
"O, W, thuis..."
Henrik Juel: 1.Kxc2 Sb3 2.. Rc1#. -1.. Ra2 -2.a3:B Bf8 -3.Bb4 Kb3 -4.Be7 a7:S -5.Sa4 Qd5
-6.Sc3 Qd4 -7.Sb1 Ra1 -8.Bf6 Kb4 -9.a2 Kc5 -10.Bg5 Kd6 -11.Bf6 Kd7 -12.Be7 Kc8 -13.Bf6 Kb8 -14.Bd8 e7 -15.B=d7 Kc8 -16.e6:R Rd8 -17.f5:B 0-0-0 -18.f4 Bc8 -19.f3 Qd8 -20.f2 d7:B -21.Bf3 Sc6 etc. (2003-8-26)
Yoav Ben-Zvi: An attempt at a coherent argument that reveals the intricate sequence of events in the resolution while refuting substantial alternatives:
The promotion of wBc3, on d8 or f8, requires 2 captures by the promoting wP. These, together with the captures by wPd3 and wPb4, account for all 4 missing Black pieces. Black captured [wBc1] at home. The other 7 missing White pieces were captured by bPs. [wBf1] cannot be released (by wPe2xd3) until [bPh7] plays bPd3xc2 completing the capture of 5 White pieces. Therefore [wBf1] was captured by bPd7xBc6 (the remaining capture by Black on a light colored square), releasing [bBc8]. This means that [wBf1] is released (by wPe2xd3) before [bBc8] is released (by capturing the previously released wB on c6) so the bB could not have been the piece captured on d3. It also could not be captured on b4 (dark colored square) so it was captured by White's promoting pawn. This means the promotion could not have been played by capture from e7 as that would imply that the 2 captures by the promoting pawn were both on dark colored squares in contradiction with the requirement to capture [bBc8]. Therefore the promotion move was wPd7-d8=B with bK standing outside the squares c8,d7,d8,e8.
Looking backward: To avoid White retrostalemate the first 2 retractions must be -1...bRa2-a1+ -2.wPa3xb4.
After this, unlocking the South-West cage and extracting bRa2 requires retraction of wPe2xd3 which requires previous uncapture of wB by bPd7xBc6, so it can be retracted home to f1. bP standing on d7 implies that a bB must previously be uncaptured and retracted home to c8, preceded by retracting BPe7-e6 to clear the path of uncaptured bB to c8. Retreat of bP to e7 is preceded by uncapture and return home of [bBf8]. With both bBs locked at home and bP on e7 the Black Central cage is locked by retracting bPd7xBc6 so bK and bQ must also be retracted home first. It follows that bKa4 needs to exit the West cage before it has been unlocked (to get back home to e8 before the Black Central cage is locked). The bK cannot exit via b5 as this implies retraction of wPc3-c4+ but, with c3 occuppied by wP, bRa2 does not have a valid exit path (not via c3 as it is obstructed by wP or via f1 as it will be occupied by wB). wP standing on c4 prevents retracting bN away from a5 so bK cannot exit via a5. The only valid exit of the bK is via b4 implying retracton of wPa2-a3 which requires bRa2 to retract to a1 (vacating a2 for the wP) which requires provision of a shield, standing on b1, to protect wKc1 from bRa1.
After the unpromotion of wBc3, White has only pawn retractions left to make until a White officer is uncaptured. This is not enough to allow Black to complete the retro-maneuvers required in preparation for retracting bPd7xBc6 (getting bBs,bK,bQ home). It follows that, at some point in the middle of its preparation maneuver, Black will need to uncapture a White officer which provides the tempo retractions needed to complete the maneuver. This is only possible by bPa7xb6. With bP standing on a7, [bRa8] cannot be retracted home via the a file so it must retract to its original corner via row 8 before the bB is locked at c8. This implies that [bRa8] is uncaptured by a wP prior to unlocking of the cage.
Uncaptures by White prior to the unlocking of the South-West cage (one available on b4 and two by pawn unpromoted from wBc3) include uncaptures of both bBs and a bR since, as noted in the above analysis, all 3 must be uncaptured and retracted home before retracting bPd7xBc6 (all of which precedes the unlocking of the South-East cage). This means that the bN is uncaptured later (on d3) so it cannot provide the shield on b1. The shield also could not be provided by [bBc8] as this bishop must be returned home when it is needed to provide the shield. The only remaining possibility is that the shield on b1 is provided by a wN that is uncaptured by bPa7xNb6. The wN on b1 is immobile until the wK can be retracted away from c1 so here too, once the unpromotion occurs Black must perform the preparations for retraction of bPd7xBc6 (which now includes return of the uncaptured bR to a8 or b8) under time pressure, completing the required maneuvers before White runs out of tempo retractions. Having determined the structural elements it is not too difficult to construct a resolution that succeeds in preparing for retraction of bPd7xBc6 before White runs out of tempo retractions. The resolution maintains the following: delay the unpromotion (known from analysis above to be wPd7-d8=B) while retracting bK to b8; bQ to d4 and bB (uncaptured on b4) to f8 and continuing by retracting -1.wBd8-? Pe7-e6 -2.Pd7-d8=B Kc8-b8 -3.Pe6xRd7+ Rd8-d7 -4.Pf5xBe6 0-0-0 -5.Pf4-f5 Bc8-e6 -6.Pf3-f4 Qd8-d4 -7.Pf2-f3 Pd7xBf6 -8.Bc6-? Nc6-a5. Following this the wB is retracted to f1 allowing the unlocking of the cage by wPe2xNd3 and bRa1 is retracted back home to h8 via c1,c3. One of the White pieces uncaptured by bPc2 unpromotes on h8. The alternative of uncapturing the bR on b4 (instead of bB) fails to complete the preparations on time.
To draw attention to the rich, unconditional, content of the resolution the stipulation could be "Squares that must have been occupied by bRa1". This problem deserves a full SPG. The best I can manage is a game of 53.0 moves. (2018-12-23)
comment

Genre: Retro
Input: Gerd Wilts, 1996-9-17
Last update: Alfred Pfeiffer, 2017-2-20 more...
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