Adrian Storisteanu: Possible fix: +bPc5. (2015-06-10)
Miguel Ambrona: The fix proposed by Adrian works.
Verified with Deadpos v.2.2. (2024-01-12)
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Anton Baumann: NL: R: 1.Ke8-d8 g7-g6 V: 1.Th1..6 Le7#
Korrektur in 'Die Schwalbe' 06/1989 S.78: +sBh7 (2022-12-30)
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Anton Baumann: 'Die Schwalbe' 08/1984 S.308: der Autor korrigiert: wBe5 statt sBe5 (2022-12-23)
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In a) Entschlagdual R: Kd5xBe4, das wurde in der Lösungsbesprechung noch kritisiert und als NL vermerkt. Hat das der PR gelassener gesehen ('geduldeter Entschlagdual'), oder gibt's noch eine korrigierte Version dieses Problems?
Anton Baumann: Korrektur in 'Die Schwalbe' 12/1975 S.422: +sLh2, +sBe5;
nun geht in a) nur noch zurück: Kd5 x Be4.
Ausgezeichnet wurde gem. Preisbericht in 'Die Schwalbe' 06/1977 S.82 die korrigierte Version 1419v. (2022-12-08)
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Adrian Storisteanu: See twin P1216951. Another possible twin (see Thomas Brand's Retroblog 11/2019):
wKc7->.h5
- 1.Kg4xRh5 Re3xQb3 & 1.Re5 Qc4# (2024-03-19)
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Adrian Storisteanu: Possible twin:
b)wSd2->d6
- 1.Sf7xRd6 Rd8xQd6 & 1.Rd8-f8 Qd6-g6# (2024-03-19)
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Henrik Juel: Cook: -1.a7xFb8=L Kb7xTa8, 1.Ka6 axb8DT#. (2004-04-01)
Mario Richter: vgl. mit P0006207 (2009-12-24)
Adrian Storisteanu: Possible (expensive, 50% more units) fix: Ka8 Bd8 / Kc8 (2+1) -- R: 1.e7xRd8=B Rd7-d8 & 1.Rc7 e8Q#. On the plus side, there is a wK in the picture now. (2016-02-10)
Adrian Storisteanu: See P1389595 (not clear which was first). (2024-03-19)
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Adrian Storisteanu: Is the star "*" in the stipulation supposed to indicate a kind of "set play" in the retro part -- in effect a "-1s dann h=1"? Because there is one:
- 1.Ke2xQf3 & 1.Ke2-e1 Qf3-d3=. (2015-08-02)
A.Buchanan: That's a clever interpretation Adrian, I am sure you are right, and it's sound according to Deadpos (2024-01-13)
Adrian Storisteanu: A more precise stipulation would be something like: (-w -s)*, dann h=1 (2024-01-14)
A.Buchanan: Good idea. The convention is that * promises at least one set play instance. (2024-01-15)
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Henrik Juel: Diagram error? -1... g5xSf4, 0... Le5 1.Sd5#. But the symmetrical solution -1... e7xSd6 etc. seems legal too. (2004-03-22)
A.Buchanan: Yes bBf8 would have died at home but bPc could capture twice to promote on c1 or e1 (2023-03-31)
A.Buchanan: Odd. The diagram is thematically symmetric, so not just missing a unit. WinChloe has the same diagram. I wondering if we are missing something from the stipulation. Does anyone have access to an archive for this? It's also odd that it was reprinted: surely there would be a comment there? I suppose it can be rendered sound by placing wTTSS somewhere symmetric. Then Black runs out of pawn captures if sLd4 is promoted. In any case, wPh7xg8=S is affordable. (2023-04-01)
Mario Richter: The reprint in 'Problem' says: "Ne e7xSd6 radi nepravilne postave" ("Not e7xSd6 because of illegal Position.") The diagram in 'Problem' is the same as here in the PDB.
How about adding black pawns on b7 and g2? (2023-04-01)
A.Buchanan: Hi Mario. I considered adding sBb5e2. That gives 10 needed captures by Black and 6 by White, including sLf8. So the try fails for *two* reasons. sBb7g2 fails even more badly. I thought that also adding wTTSS although more uneconomical in pieces defeats the try for only one reason. Also I liked the trick h7xg8=S. And it must make it harder to find the solution. Does Rawbats do simple retractors? Can you try wTa0h1 wSa7g1 as a risky initial bid, and then back off until there are no cooks? (2023-04-01)
Mario Richter: Hi Andrew, I was well aware that with adding sBb5e2 or sBb7g2 the try fails for two reasons (for [subjective] optical reasons I preferred sBb7g2 to sBb5e2]). The reason I suggested the addition of 2 black pawns was the following consideration: I cannot believe that such an experienced Retro Composer like C.E. Kemp could make such a big mistake. It's much more likely that the printer made an error by omitting two pieces.
On the other hand, if we want to correct the problem including a unique reason for the try to fail, your suggestion of adding wTa8h1+wSa7g1 (FEN=R7/N4pp1/1P1pnkp1/5n2/3b1p2/1PP5/1PP2P2/K5NR) works - rawbats gives exactly R: 1. ... Bg5xSf4, dann 1. Ld4-e5 Sf4-d5# (and says about R: Be7xSd6 - "Illegal: Mehr schwarze Bauern-Schlaege notwendig als weisse Steine fehlen") (2023-04-01)
A.Buchanan: Hi Mario, thanks for this, I agree with everything you say. It's curious that the reprint in Problem did not pick up the error. Any overlooked black units are more likely to have been lurking on dark squares, maybe sBb4d2. This forces the try to only fail for 1 reason, albeit rather banal. Does this work. Or the +wTTSS mentioned forces the solver to do a little more counting, and there is a lot more solving space to search for the h#1. Rawbats' conversational skills seem to have improved: have you integrated it with ChatGPT maybe? (2023-04-02)
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A harbinger of Dead Reckoning-style reasoning, before that rule ever existed. As sound today in 2018, as when it was composed under "insufficient material for mate" rule.
Henrik Juel: Nice to see that I am not the only freak who mixes english text with german notation (to avoid the ambiguous B)
Were you inspired by this problem in your work on Dead Reckoning, Andrew? (2020-05-04)
A.Buchanan: Ha no: when I stumbled across DP rule I knew even less about chess problems than I know now, if you can imagine, and had never encountered this one which Werner Keym unearthed and published it in "Out Of the Box". Ecclesiastes 1:9 says "There is nothing new under the sun." Mario made this point about origin of Schnoebelen promotions too. Gollon's intepretation of Chaturanga (the earliest known forebear of chess) offers fascinating possibilities for Schnoebelen promotion, which I am sure the Indian retrograde analysts of 7th Century CE were adept at exploiting, in tablets alas now lost. See https://www.chessvariants.com/historic.dir/chaturanga.html.

The "insufficient material" composition does perhaps explain Plaksin's openness to the concept of DP, at a time when perhaps some noses elsewhere were being turned up, as he later composed with Kornilov *27* other DP problems, all to be found in PDB. (2020-05-04)
Ladislav Packa: Interesting, but on YouTube I saw a game (one of the actors was Magnus Carlsson), which ended in a position with only two kings and one of the players still made a move. (2020-05-05)
A.Buchanan: http://wismuth.com/chess/illegal-moves.html contains many other games where GMs were unable to tear themselves away from playing the dead game. I think it's kind of sweet that the GMs just can't stop playing. Have you got a link to the Carlsen game please, Ladislav? (2020-05-06)
Ladislav Packa: I'm sorry, Andrew, but I don't remember. I've seen hundreds of games on youtube. But I encountered similar cases in my own practice, mostly a joke, and the game immediately ended with a smile and a handshake. (2020-05-06)
A.Buchanan: A completely different stipulation: -w, h=1 half-duplex (2024-01-11)
A.Buchanan: http://wismuth.com/chess/illegal-moves.html contains many other games where GMs were unable to tear themselves away from playing the dead game. Actually, I got this wrong for many years, but now I realize now that these moves aren't "illegal". They are impossible, because the game is already over. Legality/llegality is defined in the FIDE rules - basically just about the moves of the pieces and staying out of check. You list the legal moves, and if there are none the game is over, otherwise if there's no later checkmate possible, the position is dead. So Francois should write about "impossible" moves. But this doesn't affect the logic, just the terminology. I think it's kind of sweet that the GMs just can't stop playing, and I'm happy no arbiter stepped in, because maybe if one did then they would think about changing the rule. (2020-05-05, hidden) more ...
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Mario Richter: Ist die Stellung korrekt? Es geht auch (mit vielen Variationen): R: 1.Df7xDf8 Bg2xDh1, dann 1.g2xh1=T e7xf8=L/S= (2009-12-08)
A.Buchanan: I don't see any obvious typo or fix. This is not in WinChloe (2024-01-14)
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A.Buchanan: In both candidate solutions, counting of wPs after retraction on means it must be an original unit uncaptured on h1 so can only be wS.
The solution for b) does not work for a) because, if one retracts two promoting moves, then wPs have captured 9/10 missing Black units, while Black has 1/2 accounted for by wBc1. However wPg & bPg passed one another, which requires two more captures by a single player.
In b) the exciting retraction Qa8xh8 is blocked, however now the free pawn captures to explain g-file are shifted from 1+1 to 2+0, so bPg can pass wPg. But the vacation of d2 allows a new cook. This is fixable by shifting wPb instead of wPd. We don't need to shift it to an adjacent file: the solution is still ok if the balance is 2+1.
So "b) wPb2 to b7" fixes the cook, and it's validated by deadpos. (2024-01-15)
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Bernd Schwarzkopf: zurück: 1.Kg4xBg3 Kd3-c2 2.Kg5-g4 Ke4-d3 3.Kh5xBg5 Kf5-e4; vor: 1.g3-g4# (2024-03-29)
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siehe 9200
mri: Mehrere NL, z.B. R: Kc6xLd6 Lc5xDd6 V: 1.Ka5-a6 Dd6xc5 oder R: Kc5xTd6 Tb6xDd6 V: 1.Tb6-c6 Dd6xc6 (2007-10-25)
Mario Richter: s. P0005054 (2009-12-31)
A.Buchanan: Reasonable to suppose that P0005054 is the correction (2024-01-15)
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Adrian Storisteanu: Two wPs (e.g. +wPe4,+wPh4) can restore the glory to this nice, thoroughly mixed AUW... (2015-06-10)
A.Buchanan: Or instead +wPa5 or +wPc5. In either case, free to "downgrade" wBg1 to wS. This is more economical than adding two pawns, but separates the two islands conceptually, as b6 no longer needs to be controlled by wBg1. (2024-01-15)
mri: cooks: R: Da4-a8 Sf2xLh1 V: 1.Kxb6 Lxg2

R: Da4-a8 Sf2xTh1 V: 1.Kxb6 Th7 (2004-11-17, hidden) more ...
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Adrian Storisteanu: Possible fix: +wPh5 (4+4). (2015-08-05)
A.Buchanan: A cool fix which keeps miniature status is -bSd8 + bRd8 (2024-01-15)
A.Buchanan: Alas my suggestion is anticipated by P1202424, ah well. (2024-01-16)
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Olaf Jenkner: Wieso wird Weiß pattgesetzt? (2010-03-02)
Mario Richter: Weil der Komponist das so wollte :-)
In fs33 ist die Forderung wie folgt wiedergegeben: "Wei� nimmt einen Zug zurück und hilft, da� Schwarz sofort pattsetzen kann." (2010-03-03)
Olaf Jenkner: Ach so, h=1 bedeutet eigentlich, daß Schwarz beginnt. (2010-03-03)
Henrik Juel: Yes, it is a bit confusing; but for retros it is an old tradition that you should not interpret one move stipulations too rigorously. (2010-03-05)
Mario Richter: But at least retro play and forward play harmonize: the side that retracted last starts the forward play. (2010-03-05)
Adrian Storisteanu: Can easily make it conform to today's accepted standards (i.e., drop the half-duplex indication):

Ka1 pa2 / Kc1 pb3 (2+2)
-1b & h=1

- 1.a4xQb3 & 1.a4-a3 Qb3-d3= (2024-01-13)
Olaf Jenkner: Das wären dann viele Mütter. (2024-01-14)
A.Buchanan: @Olaf :-) (2024-01-15)
Adrian Storisteanu: :-) Just in reverse Polish notation...
(Didn't know the many fathers thing started that long ago. I totally missed both the obvious setting and the recorded keyword.) (2024-01-15)
A.Buchanan: The Originalforderung is quite clear. There is no need to represent this stipulation as a joke here. Popeye uses the unambiguous term "half-duplex" for this situation, which occurs in other help-retractors. (2024-01-12, hidden) more ...
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A.Buchanan: What is MsP, please? (2024-01-12)
Henrik Juel: Mate instead of stalemate (Mat statt Pat)
In the diagram position Black is stalemated; White retracts and mates (2024-01-12)
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Henrik Juel: C+ Popeye 4.61 (without the retraction, which is unique) (2022-11-08)
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No. 1449 HN
AV: Je crois que c'est un Fou blanc en h8 et non un Cavalier, et les derniers coups sont gxFh8=F+ Rf6-e7 fxDe8=D+ (au lieu de fxCg8=C#). Avec l'antérieur cxTb8=T, cela donne une "Allumwandlung" avec une pièce noire prise de la même nature. (2005-06-09)
Henrik Juel: You must be right, AV, because with wSh8 the retroplay might be the bland -1.f7xDe8=D Kf6 etc. without unpromotion on h8. (2005-06-13)
Michel Caillaud: Indeed the diagram is wrong : there should be a white Bishop on h8
AUW spread over retro play (-1.fxDe8=D+ Kf6-e7 -2.gxLh8=L+ ...-n.cxTb8=T) and forward play 1.fxSg8=S#
Matching nature of promoted piece and piece captured by promotion. (2023-03-25)
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SCHRECKE: Petrovic: P0001941 (2023-11-28)
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Henrik Juel: a real gem (2023-05-20)
Adrian Storisteanu: Not an Allentschlag, there is no pawn uncapture. (2023-05-21)
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Mario Richter: I think, the intended solution is R: -1.Qa1-g1, then 1.Qd1#
Further retraction: -1. ... g3-g2 -2.c2-c3 g4-g3 -3.Qh8-a1 g5-g4 -4.h7-h8=Q h3-h2 -5.h6-h7 f3-f2 -6.h5-h6 h6xBg5 -7. Bf6-g5 h7-h6 -8.Rg1-g8 f4-f3 -9.Ra1-g1 f5-f4 -10.Bb2-f6 f6-f5 -11.Bc1-b2 f7-f6 -12.b2-b4 Kb4-a4 -13.h4-h5 Qa4-a5 (2010-01-07)
Hans-Jürgen Manthey: zurück Da1-g1, vor Da1-d1#
R. 1. g3-g2 c2-c3 2. g4-g3 Dh8-a1 3. g5-g4 h7-h8D 4. f3-f2 h6-h7 5. f4-f3 h5-h6 6. h6xLg5 Lf6-g5 8. f5-f4 Lb2-f6 9. f6-f5 Tg1-g8 10. f7-f6 Ta1-g1 11. h3-h2 Lc1-b2 12. h7-h6 b2-b4 13. b4xSa3 Sb1-a3 14. c5xSb4 Sd5-b4 15. d6xTc5 Sf6-d5 16. Kb4-a4 Tg5-c5 17. Kc4-b4 Tg8-g5 18. Dc3-a5 Ta3-a6 19. Sa6-b8 g7-g8T 20. Lb8-a7 g6-g7 21. a7xDb6 Dg1-b6 22. Sc5-a6 g5-g6 23. Tb6-b7 g4-g5 24. Ta6-b6 g3-g4 25. g4xLh3 Sg8-f6 26. Dh8-c3 Dd1-g1 27. Tb7-c7 Lf1-h3 28. Ta4-a6 g2-g3 29. Kd5-c4 Th3-a3 30. Lc7-b8 Th1-h3 31. La5-c7 h4-h5 32. Tb6-b7 h2-h4 33. Sb7-c5 Kb8-a8 34. g5-g4 Kc7-b8 35. Sc5-b7 Kd8-c7 36. Sa6-c5 Ke7-d8 37. Tb8-b6 g7-g8S 38. Ta8-b8 Kf6-e7 39. sb8-a6 Kf5-f6 40. Ta3-a4 f6xSg7 41. Se8-g7+ Kg4-f5 42. Lc3-a5 Kf3-g4 43. b7-b5 Kf2-f3 44. c7-c6 f5-f6 45. Lg7-c3 Ke1-f2 46. Sf6-e8 Kf2-e1 47. Te3-a3 Ke1-f2 48. Dd8-h8 f4-f5 49. Te8-e3 Kf2-e1 50. Ke6-d5 Ke1-f2 51. Ke7-e6 Kf2-e1 52. Th8-e8 Ke1-f2 53. Ke8-e7 f2-f4 54. e7xSd6 Sf5-d6+ 55. Lf8-g7 Sh4-f5 56. Sg8-f6 Sf3-h4 57. g7-g5 Sg1-f3 (2023-03-11)
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Arnold Beine: Die erste Lösung geht nicht, weil am Ende der sKa3 noch das Fluchtfeld b4 hat.
Korrekturvorschlag: +sBb4 (dann geht nur die 1. Lösung) und als Zwilling "b) -sBb4" (dann geht nur die 2. Lösung) (2022-08-28)
TBr: Forderung muss wohl lauten: -1, dann H#2 Rex Multiplex, 2 Lösungen (2009-06-04, hidden) more ...
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A.Buchanan: Deadpos v2 can now solve this, even though PDB animation can't manage to show it:
6k1/8/6K1/8/8/8/8/8 b }}= r1 }}= flip }}= m2 }}= flip }}= r1 }}= flip }}= #1 (p)
h5xRg6 flip then g8h7 h5h4 flip h6xPh7 flip then h7h8q#
f5xRg6 flip then g8h7 f5f4 flip h6xPh7 flip then h7h8q#
g5xPg6 flip then g8h7 g5f6 flip h6xPh7 flip then h7h8q#
g5xPg6 flip then g8h7 g5f6 flip h6xPh7 flip then h7h8r#
g5xPg6 flip then g8h7 g5h4 flip h6xPh7 flip then h7h8q#
g5xPg6 flip then g8h7 g5g4 flip h6xPh7 flip then h7h8q#
g5xPg6 flip then g8h7 g5f4 flip h6xPh7 flip then h7h8q#
f6xPg6 flip then g8h8 f6f7 flip h7xPg6 flip then g6g7#
nsols 8 (2024-01-05)
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Henrik Juel: The forward play is 1.Ld8 Ka6/Kb8 2.b8=S/Sc6# (2022-10-14)
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Motto: "Our play"
Originalforderung 1.White played last, retract his move 2.Black retracts his last move 3.Black plays so as to enable-- 4.White to mate 5.No Queens
A.Buchanan: The issue is that wPb3 covers a4. Rotate the board clockwise by 90 deg & shift wPc7 to c5 gives unique queenless solution R: 1. Se6xTf4 g3xTf2, dann 1. Tf5 Te2#, together with 68 queeny tries. (2022-11-13)
Adrian Storisteanu: The wQ is, unfortunately, extremely deadly. In your suggested position, there are still cooks, e.g.,
- 1.Kg6xPg7 g3xQf2 & 1.g3-g2 Qf2-e3#
- 1.Sg2xRf4 e3xQf2 & 1.Rf4-e4 Qf2-f6# (2022-11-13)
A.Buchanan: Yes I make no attempt to remove the "keine Damen" constraint, which is a kind of thematic aid that Baird employs quite often. deadpos identifies 69 solutions in the rotated position 8/6K1/8/2Ppk3/5N2/8/5p2/8, of which 68 require a queen (2022-11-13)
Adrian Storisteanu: The "no queens" constraint seems here almost thematic, as the intended solution works just as fine with a wQ uncapture: - 1.Sc5xRe6 h7xQg6 & 1.Re6-d6 Qg6-g5#... (2022-11-13)
Adrian Storisteanu: (What is "deadpos"?) (2022-11-13)
Adrian Storisteanu: A quick fix along your intention is also -wPb3,+bPc4 (90 queeny tries). (2022-11-13)
A.Buchanan: deadpos is a software engine that determines very efficiently whether a position is dead or not, and allows stipulations such as h=, hdp, h#. Simple retractions are also important for DP last move problems, and since no-one who's written help retractor functionality has ever made it public, this is of use for testing neglected problems such as Mrs Baird's, which have little to do with DP rule. A broader name for this engine will probably emerge at some point.
Your fix -wPb3, + bPc4 also works! (2022-11-13)
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Adrian Storisteanu: See also P0002484. (2024-03-19)
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Forderung im 'Boten von der Ybbs': "Weiß nimmt seinen letzten Zug zurück, dann nimmt Schwarz seinen letzten Zug zurück und dann zieht Schwarz so, daß Weiß in einem Zug matt-setzen kann!"

Motto: "Das Waidhofner Problem"

als Autor ist angegeben "Dr. S. Knirt", dabei dürfte es sich um ein Pseudonym von Dr. Otto Trinks handeln (S.Knirt rückwärts gelesen ergibt trinKS)
Adrian Storisteanu: See P0002517. (2024-03-19)
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corrects P0003922
Henrik Juel: R: 1... h2-h1=S+ 2.a7-a8=L Kc8-d8, 1.h1=T a8=D# (2023-04-13, hidden)
A.Buchanan: Mario was kind enough to check this 2-Jul-2021. I hope it's ok if I quote his email:

The trick with the light-squared black Bishop is fine,
but makes things too complicated for rawbats.
It will happily retract e.g.
R: 1. ... h2-h1=S+ 2. Lb7-a8 Ke7xDd8, dann 1. Kd6 Df6#
without noticing that the retractions lead to a conflict
on the g-file: either wPh2 captured the original Bishop c8
on the g-file, then bPg7 was not available a a capture object
for the remaining white pawn captures, or wPh2 captured the
original bPg7 on the g-file, then the original light-squared
black bishop c8 was not available a capture object
for the remaining white pawn captures f2xe3xd4 (both on dark squares).
So brain-checking your retractor and your logical argumentation
I found no defects, and I think the problem is sound now. (2023-04-14, hidden) more ...
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See P0005542.
A.Buchanan: WinChloe incorrectly reports this as M.Rittirsch. But what is the true source & date of this correction? Obviously, it wasn't F.Lapya. (2024-01-19)
Adrian Storisteanu: I'd would have put a wB (instead of the wQ) on d8 -- a subtler non-standard material?!... (2024-01-19)
Adrian Storisteanu: (... Ooops, but then no 'AUW'.) (2024-01-19)
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