Faster Forced Mate

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Rebel, chrisw

MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Forced Mate #57 source ChestUCI.epd position 6331

Post by MikeGL »

Thanks Jon, I don't have these two position yet.


regards
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Old theme -Forced Mate#66 source ChestUCI.epd position 6351

Post by MikeGL »

[D]8/p1p3p1/p5Pp/8/p1p5/6r1/1QP2p1k/N4Kb1 w - - 0 1

White to Play, Mate in #66 source ChestUCI.epd position 6351

Same old theme by Bláthy, but same old difficult puzzle for
most engines due to zugzwangs.
Not found in yacpdb and not in one of Arpad Rusz posted puzzle/solutions.

Solution of above puzzle follows -
-
-
-
-


[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.03"]
[Round "?"]
[White "McBrain_2017"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/p1p3p1/p5Pp/8/p1p5/6r1/1QP2p1k/N4Kb1 w - - 0 1"]
[Termination "normal"]
[PlyCount "131"]
[WhiteType "human"]
[BlackType "human"]
[Comment "bm #66;"]

1. Qe5 c6 2. Qh5+ Rh3 3. Qg4 Rg3 4. Qh4+ Rh3 5. Qf4+ Rg3 6. Qe5 a5 7. Qh5+
Rh3 8. Qg4 Rg3 9. Qh4+ Rh3 10. Qf4+ Rg3 11. Qe5 c5 12. Qh5+ Rh3 13. Qg4 Rg3
14. Qh4+ Rh3 15. Qf4+ Rg3 16. Qe5 a6 17. Qh5+ Rh3 18. Qg4 Rg3 19. Qh4+ Rh3
20. Qf4+ Rg3 21. Qe5 a3 22. Qh5+ Rh3 23. Qg4 Rg3 24. Qh4+ Rh3 25. Qf4+ Rg3
26. Qe5 a4 27. Qh5+ Rh3 28. Qg4 Rg3 29. Qh4+ Rh3 30. Qf4+ Rg3 31. Qe5 a2
32. Qh5+ Rh3 33. Qg4 Rg3 34. Qh4+ Rh3 35. Qf4+ Rg3 36. Qe5 a3 37. Qh5+ Rh3
38. Qg4 Rg3 39. Qh4+ Rh3 40. Qf4+ Rg3 41. Qe5 c3 42. Qh5+ Rh3 43. Qg4 Rg3
44. Qh4+ Rh3 45. Qf4+ Rg3 46. Qe5 c4 47. Qh5+ Rh3 48. Qg4 Rg3 49. Qh4+ Rh3
50. Qf4+ Rg3 51. Qe5 a5 52. Qh5+ Rh3 53. Qg4 Rg3 54. Qh4+ Rh3 55. Qf4+ Rg3
56. Qe5 a4 57. Qh5+ Rh3 58. Qg4 Rg3 59. Qh4+ Rh3 60. Qf4+ Rg3 61. Qe5 h5
62. Qxh5+ Rh3 63. Qg5 Rg3 64. Qe5 Kh1 65. Qxg3 Bh2 66. Qg2# 1-0
[/pgn]


regards
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Funny again Re: Forced Mate #35 ChestUCI.epd pos:6253

Post by MikeGL »

Most engines have even difficulty finding the drawing line for white,
even more difficult to find the win.

A Funny Position where black is winning according to engine evals.
Forced Mate in #35 but almost all engines prefer the position of black.
Many zugzwang position (via king triangulation at d6 or g1). Triangulate at d6 square if d5 is occupied by a pawn or g1 square if e3 is occupied.
Other dark squares are not possible for triangulation because the Bb2
would deliver deadly checks and the Qa1 would be activated too, and
would allow black to win the game.

[d]8/8/2N1p3/p7/rp2p3/kp6/p1pQN2K/bb6 w - - 0 1
White to Play, Mate in 35 /source: ChestUCI.epd position 6253

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.05"]
[Round "?"]
[White "McBrain_2017"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/8/2N1p3/p7/rp2p3/kp6/p1pQN2K/bb6 w - - 0 1"]
[Termination "normal"]
[PlyCount "69"]
[WhiteType "human"]
[BlackType "human"]
[Comment "bm #35;"]

1. Qc1+ Bb2 2. Ne5 a1=Q 3. Nc4+ Ka2 4. Kh3 Ra3 5. Kg4 Ra4 6. Kh5 Ra3 7. Kg6
Ra4 8. Kf7 e5 9. Kf6 Ra3 10. Ke6 Ra4 11. Kd5 Ra3 12. Kd6 Ra4 13. Kc6 Ra3
14. Kb5 e3 15. Kc6 Ra4 16. Kd6 Ra3 17. Kd7 Ra4 18. Kc6 Ra3 19. Kb5 e4 20.
Kc6 Ra4 21. Kd5 Ra3 22. Kxe4 Ra4 23. Kf3 Ra3 24. Kg2 Ra4 25. Kg1 Ra3 26.
Kf1 Ra4 27. Kg2 Ra3 28. Kf3 Ra4 29. Ke4 Ra3 30. Kd5 Ra4 31. Kc6 Ra3 32. Kb5
a4 33. Kc6 Bg7 34. Qxa3+ bxa3 35. Nc1# 1-0
[/pgn]


Not posted in one of Arpad Rusz's puzzle and not at yacpdb too.

regards
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Forced Mate #34

Post by MikeGL »

Published as Mate in #34. Source ChestUCI.epd position: 6246
[d]R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1
White to Play, Mate in #34

According to engines, there are many other possible winning lines by
activating white K via g2 and then attacking blacks position.
But haven't verified if that idea would mate longer or shorter.

Possible correct solution below follows:
This solution is quite artistic because the position of black crumbles by
just maneuvering whites king to a1 and back to h1. The idea is to lose tempo so
white has the possibility to checkmate via Rb8-Rb1-Rg1-Rg7-Rh7# checkmate.

With this idea of white, the pawns of black are forcibly pushed until no
more pawns can be pushed.

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.07"]
[Round "?"]
[White "2"]
[Black "McBrain_2017"]
[Result "*"]
[TimeControl "0+2"]
[SetUp "1"]
[FEN "R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1"]
[Termination "unterminated"]
[PlyCount "67"]
[WhiteType "human"]
[BlackType "human"]
[Comment "bm #34;"]

1. Rb8 h3 2. Kg1 Bc5 (2. .. c6 3. Rb7 Bc7 4. Rxc7 Ne7 5. Rxe7 h4 6. Rh7#)
3. Kf1 Bb6 4. Ke1 Bc5 5. Kd1 Bb6 6. Kc1 Bc5 7. Kb1 Bb6 8. Ka1 a5 (8. .. Bc5
9. Rb1 Ne7 10. Rg1 Bd4 11. exd4 Nac6 12. Rg7 Nxd4 13. Rh7#) 9. Kb1 Bc5 10.
Kc1 Bb6 11. Kd1 Bc5 12. Ke1 Bb6 13. Kf1 Bc5 14. Kg1 Bb6 15. Kh1 a4 (15. ..
Bc5 16. Rb1 Ne7 17. Rg1+-) 16. Kg1 Bc5 17. Kf1 Bb6 18. Ke1 Bc5 19. Kd1 Bb6
20. Kc1 Bc5 21. Kb1 Bb6 22. Ka1 h4 23. Kb1 Bc5 24. Kc1 Bb6 25. Kd1 Bc5 26.
Ke1 Bb6 27. Kf1 Bc5 28. Kg1 Bb6 29. Kh1 Bc5 30. Rb1 Ne7 31. Rg1 Bd4 32.
exd4 c6 33. Rg7 c5 34. Rh7#
[/pgn]


Haven't seen this solution anywhere else. yacpdb didn't supply solutions.

regards
Vinvin
Posts: 5228
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: Forced Mate #34

Post by Vinvin »

MikeGL wrote:Published as Mate in #34. Source ChestUCI.epd position: 6246
[d]R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1
White to Play, Mate in #34

According to engines, there are many other possible winning lines by
activating white K via g2 and then attacking blacks position.
But haven't verified if that idea would mate longer or shorter.

Possible correct solution below follows:
This solution is quite artistic because the position of black crumbles by
just maneuvering whites king to a1 and back to h1. The idea is to lose tempo so
white has the possibility to checkmate via Rb8-Rb1-Rg1-Rg7-Rh7# checkmate.
SF-MF after 17h30m :

Code: Select all

FEN: R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1

Stockfish_170708_matefinder:
...
---------------------------------------------------------------------------
 50/94	7:17:22	437 679 782k	16 678k	+7,78	1.Kg1 c6 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 Kxh6 8.Ne2 Bc5 9.f4 Ne7 10.d4 Bb6 11.d5 Kg6 12.c7 Nec8 13.e5 Bxc7 14.d6 Nxd6 15.exd6 Nb5 16.dxc7 Nxc7 17.Ra7 Nd5 18.Rxa6+ Kf7 19.Rxa3 Ne3+ 20.Kh3 Nxc2 21.Rxc3 Nb4 22.Kxh4 Nd5 23.Rd3 Ne7 24.Nc3 Nc6 25.Kg4 Ke6 26.Ne4 Kf7 27.Rd2 Ne7 28.Rd7 Ke6 29.Ra7 Kf7 30.Kg3
 50/94	7:17:22	437 679 782k	16 678k	+50,13	1.Kg2 c6 2.dxc6 Bd8 3.Nd5 Kh7 4.Kh3 Ba5 5.Ne7 Bd8 6.Nxc8 Nxc6 7.Nxd6 Bg5 8.Nf7 Bxh6 9.Nxh6 Nb4 10.Nf7 Nxc2 11.Rxa6 Kg7 12.Nd6 Nb4 13.Rxa3 Nd5 14.Ra5 Nb4 15.Kxh4 Kf8 16.Rc5 Nxa2 17.Ne4 Nc1 18.Rc8+ Kg7 19.Rc7+ Kg6 20.Nxc3 Nb3 21.Ne4 Kh6 22.Rc6+ Kg7 23.Rc3 Na5 24.Rc7+ Kg6 25.Rc5 Nb3 26.Rb5 Na1 27.Rb6+ Kf7 28.Nc3 Nc2 29.Kxh5 Kg7 30.Rb3 Na1 31.Rb7+ Kf8 32.Rb6 Kf7 33.Nd5 Ke8 34.Rb1
 50/94	7:17:22	437 679 782k	16 678k	+58,04	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Nxf8 14.Rxf8 Kxh6 15.Rf7 Kg6 16.Rxc7 Kf6 17.Rxc3 Ke5 18.Rxa3 Kxd5 19.Rxa6 Ke6 20.Ra4 Kd7 21.Rh4 d5 22.Rxh5 Kc6 23.Rxh3 Kc5 24.Rh4 d4 25.Rh5+ Kc6 26.Rh3 Kb6 27.Rb3+ Kc6 28.Rd3 Kc5 29.Ra3 Kd6 30.Rh3 Kd5
---------------------------------------------------------------------------
 51/94	12:51:05	778 099 061k	16 818k	+7,75	1.Kg1 c5 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 h3+ 8.Nxh3 Kxh6 9.Nf4 Nxc6 10.Rxc8 Nb4 11.Ne2 Bg7 12.Nxc3 Nxc2 13.Nd5 Ne1+ 14.Kf1 Nxd3 15.Ke2 Ne5 16.f4 Ng6 17.Rc6 Kh7 18.f5 Ne5 19.Rxa6 Bf8 20.Ra7+ Kh6 21.Nf4 Ng4 22.h4 Ne5 23.Ra6+ Kh7 24.Ne6 Bb4 25.Ng5+ Kg8 26.Ra8+ Kg7 27.Ra7+ Kg8 28.Ne6 Nc6 29.Rg7+ Kh8 30.Rc7 Ne5 31.Ke3 Ng4+ 32.Kf3 Ne5+ 33.Kf4 Bd6 34.Rc8+ Kh7 35.f6
 51/94	12:51:05	778 099 061k	16 818k	+53,19	1.Kg2 c6 2.dxc6 d5 3.Kh3 Bd8 4.Nxd5 Kh7 5.c7 Bxc7 6.Nxc7 Kxh6 7.Nd5 Kg6 8.e4 Nd6 9.Rxa7 Nxe4 10.Kxh4 a5 11.Rxa5 Kf7 12.Ra7+ Ke6 13.Re7+ Kxd5 14.Rxe4 Kxe4 15.Kxh5 Kf4 16.Kh4 Kf5 17.Kg3 Ke4 18.Kg4 Ke5 19.f4+ Ke4 20.f5 Ke3 21.Kh5 Kd2 22.f6 Kxc2 23.f7 Kd2 24.f8Q c2 25.Qxa3 c1Q 26.Qxc1+ Kxc1 27.Kg6 Kd2 28.h4 Ke3 29.h5 Kf4 30.h6 Kg4 31.h7 Kh3
 51/94	12:51:05	778 099 061k	16 818k	+58,04	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Nxf8 14.Rxf8 Kxh6 15.Rf7 Kg6 16.Rxc7 Kf6 17.Rxc3 Ke5 18.Rxa3 Kxd5 19.Rxa6 Ke6 20.Ra5 d5 21.Ra6+ Ke7 22.Rh6 Kd7 23.Rh7+ Kc6 24.Rxh5 Kc5 25.Rxh3 Kb4 26.Rh7 Kc5 27.Rh5 Kd6 28.Rh6+ Ke5 29.Rh4 Kf6 30.Rg4 d4 31.Rxd4 Kg7 32.Rg4+ Kf7 33.Rf4+ Kg6 34.Ra4 Kf5 35.Ra3 Kf6 36.Rf3+ Kg6 37.a4 Kh5
---------------------------------------------------------------------------
 51/94	13:04:13	793 308 559k	16 860k	+7,75	1.Kg1 c5 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 h3+ 8.Nxh3 Kxh6 9.Nf4 Nxc6 10.Rxc8 Nb4 11.Ne2 Bg7 12.Nxc3 Nxc2 13.Nd5 Ne1+ 14.Kf1 Nxd3 15.Ke2 Ne5 16.f4 Ng6 17.Rc6 Kh7 18.f5 Ne5 19.Rxa6 Bf8 20.Ra7+ Kh6 21.Nf4 Ng4 22.h4 Ne5 23.Ra6+ Kh7 24.Ne6 Bb4 25.Ng5+ Kg8 26.Ra8+ Kg7 27.Ra7+ Kg8 28.Ne6 Nc6 29.Rg7+ Kh8 30.Rc7 Ne5 31.Ke3 Ng4+ 32.Kf3 Ne5+ 33.Kf4 Bd6 34.Rc8+ Kh7 35.f6
 51/94	13:04:13	793 308 559k	16 860k	+53,19	1.Kg2 c6 2.dxc6 d5 3.Kh3 Bd8 4.Nxd5 Kh7 5.c7 Bxc7 6.Nxc7 Kxh6 7.Nd5 Kg6 8.e4 Nd6 9.Rxa7 Nxe4 10.Kxh4 a5 11.Rxa5 Kf7 12.Ra7+ Ke6 13.Re7+ Kxd5 14.Rxe4 Kxe4 15.Kxh5 Kf4 16.Kh4 Kf5 17.Kg3 Ke4 18.Kg4 Ke5 19.f4+ Ke4 20.f5 Ke3 21.Kh5 Kd2 22.f6 Kxc2 23.f7 Kd2 24.f8Q c2 25.Qxa3 c1Q 26.Qxc1+ Kxc1 27.Kg6 Kd2 28.h4 Ke3 29.h5 Kf4 30.h6 Kg4 31.h7 Kh3
 52/94	13:04:13	793 308 559k	16 860k	+M41	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Kxh6 14.Nxd7 Kg6 15.Rc4 Kf5 16.Rxc7 Ke4 17.Nb6 Kd4 18.Rc4+ Ke5 19.Rxc3 Kd4 20.Rc4+ Ke5 21.Ra4 Kf5 22.Rxa6 Ke5 23.Ra4 Kf6 24.Rxa3 Ke7 25.Ra6 Kf7 26.Nc4 Kf6 27.Ra7 Kf5 28.Ra5 Ke4 29.Nxd6+ Kf4 30.Ne4 Kxe4 31.d6 Kd4 32.Rxh5 Ke3 33.d7 Kd2 34.d8Q+ Kc3 35.Rxh3+ Kb4
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Forced Mate #34

Post by MikeGL »

Vinvin wrote:
MikeGL wrote:Published as Mate in #34. Source ChestUCI.epd position: 6246
[d]R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1
White to Play, Mate in #34

According to engines, there are many other possible winning lines by
activating white K via g2 and then attacking blacks position.
But haven't verified if that idea would mate longer or shorter.

Possible correct solution below follows:
This solution is quite artistic because the position of black crumbles by
just maneuvering whites king to a1 and back to h1. The idea is to lose tempo so
white has the possibility to checkmate via Rb8-Rb1-Rg1-Rg7-Rh7# checkmate.
SF-MF after 17h30m :

Code: Select all

FEN: R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1

Stockfish_170708_matefinder:
...
---------------------------------------------------------------------------
 50/94	7:17:22	437 679 782k	16 678k	+7,78	1.Kg1 c6 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 Kxh6 8.Ne2 Bc5 9.f4 Ne7 10.d4 Bb6 11.d5 Kg6 12.c7 Nec8 13.e5 Bxc7 14.d6 Nxd6 15.exd6 Nb5 16.dxc7 Nxc7 17.Ra7 Nd5 18.Rxa6+ Kf7 19.Rxa3 Ne3+ 20.Kh3 Nxc2 21.Rxc3 Nb4 22.Kxh4 Nd5 23.Rd3 Ne7 24.Nc3 Nc6 25.Kg4 Ke6 26.Ne4 Kf7 27.Rd2 Ne7 28.Rd7 Ke6 29.Ra7 Kf7 30.Kg3
 50/94	7:17:22	437 679 782k	16 678k	+50,13	1.Kg2 c6 2.dxc6 Bd8 3.Nd5 Kh7 4.Kh3 Ba5 5.Ne7 Bd8 6.Nxc8 Nxc6 7.Nxd6 Bg5 8.Nf7 Bxh6 9.Nxh6 Nb4 10.Nf7 Nxc2 11.Rxa6 Kg7 12.Nd6 Nb4 13.Rxa3 Nd5 14.Ra5 Nb4 15.Kxh4 Kf8 16.Rc5 Nxa2 17.Ne4 Nc1 18.Rc8+ Kg7 19.Rc7+ Kg6 20.Nxc3 Nb3 21.Ne4 Kh6 22.Rc6+ Kg7 23.Rc3 Na5 24.Rc7+ Kg6 25.Rc5 Nb3 26.Rb5 Na1 27.Rb6+ Kf7 28.Nc3 Nc2 29.Kxh5 Kg7 30.Rb3 Na1 31.Rb7+ Kf8 32.Rb6 Kf7 33.Nd5 Ke8 34.Rb1
 50/94	7:17:22	437 679 782k	16 678k	+58,04	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Nxf8 14.Rxf8 Kxh6 15.Rf7 Kg6 16.Rxc7 Kf6 17.Rxc3 Ke5 18.Rxa3 Kxd5 19.Rxa6 Ke6 20.Ra4 Kd7 21.Rh4 d5 22.Rxh5 Kc6 23.Rxh3 Kc5 24.Rh4 d4 25.Rh5+ Kc6 26.Rh3 Kb6 27.Rb3+ Kc6 28.Rd3 Kc5 29.Ra3 Kd6 30.Rh3 Kd5
---------------------------------------------------------------------------
 51/94	12:51:05	778 099 061k	16 818k	+7,75	1.Kg1 c5 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 h3+ 8.Nxh3 Kxh6 9.Nf4 Nxc6 10.Rxc8 Nb4 11.Ne2 Bg7 12.Nxc3 Nxc2 13.Nd5 Ne1+ 14.Kf1 Nxd3 15.Ke2 Ne5 16.f4 Ng6 17.Rc6 Kh7 18.f5 Ne5 19.Rxa6 Bf8 20.Ra7+ Kh6 21.Nf4 Ng4 22.h4 Ne5 23.Ra6+ Kh7 24.Ne6 Bb4 25.Ng5+ Kg8 26.Ra8+ Kg7 27.Ra7+ Kg8 28.Ne6 Nc6 29.Rg7+ Kh8 30.Rc7 Ne5 31.Ke3 Ng4+ 32.Kf3 Ne5+ 33.Kf4 Bd6 34.Rc8+ Kh7 35.f6
 51/94	12:51:05	778 099 061k	16 818k	+53,19	1.Kg2 c6 2.dxc6 d5 3.Kh3 Bd8 4.Nxd5 Kh7 5.c7 Bxc7 6.Nxc7 Kxh6 7.Nd5 Kg6 8.e4 Nd6 9.Rxa7 Nxe4 10.Kxh4 a5 11.Rxa5 Kf7 12.Ra7+ Ke6 13.Re7+ Kxd5 14.Rxe4 Kxe4 15.Kxh5 Kf4 16.Kh4 Kf5 17.Kg3 Ke4 18.Kg4 Ke5 19.f4+ Ke4 20.f5 Ke3 21.Kh5 Kd2 22.f6 Kxc2 23.f7 Kd2 24.f8Q c2 25.Qxa3 c1Q 26.Qxc1+ Kxc1 27.Kg6 Kd2 28.h4 Ke3 29.h5 Kf4 30.h6 Kg4 31.h7 Kh3
 51/94	12:51:05	778 099 061k	16 818k	+58,04	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Nxf8 14.Rxf8 Kxh6 15.Rf7 Kg6 16.Rxc7 Kf6 17.Rxc3 Ke5 18.Rxa3 Kxd5 19.Rxa6 Ke6 20.Ra5 d5 21.Ra6+ Ke7 22.Rh6 Kd7 23.Rh7+ Kc6 24.Rxh5 Kc5 25.Rxh3 Kb4 26.Rh7 Kc5 27.Rh5 Kd6 28.Rh6+ Ke5 29.Rh4 Kf6 30.Rg4 d4 31.Rxd4 Kg7 32.Rg4+ Kf7 33.Rf4+ Kg6 34.Ra4 Kf5 35.Ra3 Kf6 36.Rf3+ Kg6 37.a4 Kh5
---------------------------------------------------------------------------
 51/94	13:04:13	793 308 559k	16 860k	+7,75	1.Kg1 c5 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 h3+ 8.Nxh3 Kxh6 9.Nf4 Nxc6 10.Rxc8 Nb4 11.Ne2 Bg7 12.Nxc3 Nxc2 13.Nd5 Ne1+ 14.Kf1 Nxd3 15.Ke2 Ne5 16.f4 Ng6 17.Rc6 Kh7 18.f5 Ne5 19.Rxa6 Bf8 20.Ra7+ Kh6 21.Nf4 Ng4 22.h4 Ne5 23.Ra6+ Kh7 24.Ne6 Bb4 25.Ng5+ Kg8 26.Ra8+ Kg7 27.Ra7+ Kg8 28.Ne6 Nc6 29.Rg7+ Kh8 30.Rc7 Ne5 31.Ke3 Ng4+ 32.Kf3 Ne5+ 33.Kf4 Bd6 34.Rc8+ Kh7 35.f6
 51/94	13:04:13	793 308 559k	16 860k	+53,19	1.Kg2 c6 2.dxc6 d5 3.Kh3 Bd8 4.Nxd5 Kh7 5.c7 Bxc7 6.Nxc7 Kxh6 7.Nd5 Kg6 8.e4 Nd6 9.Rxa7 Nxe4 10.Kxh4 a5 11.Rxa5 Kf7 12.Ra7+ Ke6 13.Re7+ Kxd5 14.Rxe4 Kxe4 15.Kxh5 Kf4 16.Kh4 Kf5 17.Kg3 Ke4 18.Kg4 Ke5 19.f4+ Ke4 20.f5 Ke3 21.Kh5 Kd2 22.f6 Kxc2 23.f7 Kd2 24.f8Q c2 25.Qxa3 c1Q 26.Qxc1+ Kxc1 27.Kg6 Kd2 28.h4 Ke3 29.h5 Kf4 30.h6 Kg4 31.h7 Kh3
 52/94	13:04:13	793 308 559k	16 860k	+M41	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Kxh6 14.Nxd7 Kg6 15.Rc4 Kf5 16.Rxc7 Ke4 17.Nb6 Kd4 18.Rc4+ Ke5 19.Rxc3 Kd4 20.Rc4+ Ke5 21.Ra4 Kf5 22.Rxa6 Ke5 23.Ra4 Kf6 24.Rxa3 Ke7 25.Ra6 Kf7 26.Nc4 Kf6 27.Ra7 Kf5 28.Ra5 Ke4 29.Nxd6+ Kf4 30.Ne4 Kxe4 31.d6 Kd4 32.Rxh5 Ke3 33.d7 Kd2 34.d8Q+ Kc3 35.Rxh3+ Kb4
Thanks for that more than 17hr of position-crunching on your
powerful hardware.

But I am not sure if you just found out and uncovered a cook for this mate puzzle or whether SF-MF missed the #M34 because it played 4.f4 which
untangles the pieces of black and gives black a bit of resistance against
#M34.


52/94 13:04:13 793 308 559k 16 860k +M41 1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Kxh6 14.Nxd7 Kg6 15.Rc4 Kf5 16.Rxc7 Ke4 17.Nb6 Kd4 18.Rc4+ Ke5 19.Rxc3 Kd4 20.Rc4+ Ke5 21.Ra4 Kf5 22.Rxa6 Ke5 23.Ra4 Kf6 24.Rxa3 Ke7 25.Ra6 Kf7 26.Nc4 Kf6 27.Ra7 Kf5 28.Ra5 Ke4 29.Nxd6+ Kf4 30.Ne4 Kxe4 31.d6 Kd4 32.Rxh5 Ke3 33.d7 Kd2 34.d8Q+ Kc3 35.Rxh3+ Kb4


Because if 4.f4 on above variation is not played, the Bb6 > 4...Bxe3 >
6...Bd4 is not possible and cannot harass the Nf6 which is already
positioned for the planned checkmate.

But anyway, below is #M40 from yacpdb site but solution was not provided there.

[d]2B2bk1/p1p1p1p1/2P1P1Pp/p1P5/2P4p/Pp5P/bP1K4/8 w - - 0 1
Source yacpdb.org /published as #M40

[pgn]
[Event "Computer chess game"]
[Site "Talkchess]
[Date "2017.07.10"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[BlackElo "2400"]
[TimeControl "0+2"]
[SetUp "1"]
[FEN "2B2bk1/p1p1p1p1/2P1P1Pp/p1P5/2P4p/Pp5P/bP1K4/8 w - - 0 1"]
[Termination "normal"]
[PlyCount "79"]
[WhiteType "human"]
[BlackType "human"]

1. Kc1 Kh8 2. Bd7 Kg8 3. Be8 Kh8 4. Bf7 h5 5. Be8 Kg8 6. Bd7 Kh8 7. Bc8 Kg8
8. Bb7 Kh8 9. Ba6 Kg8 10. Bc8 Kh8 11. Bd7 Kg8 12. Be8 Kh8 13. Bf7 a4 14.
Be8 Kg8 15. Bd7 Kh8 16. Bc8 Kg8 17. Ba6 Kh8 18. Bb5 Kg8 19. Bxa4 a6 20. Bb5
a5 21. Ba6 Kh8 22. Bb7 Kg8 23. Bc8 Kh8 24. Bd7 Kg8 25. Be8 Kh8 26. Bf7 a4
27. Be8 Kg8 28. Bd7 Kh8 29. Bc8 Kg8 30. Ba6 Kh8 31. Bb5 Kg8 32. Bxa4 Kh8
33. Bb5 Kg8 34. a4 Kh8 35. a5 Bb1 36. Kxb1 Kg8 37. a6 Kh8 38. a7 Kg8 39.
a8=Q Kh8 40. Qxf8# 1-0
[/pgn]

Puzzle not yet in Arpad's post from previous page of this thread,
I can't find solution anywhere else.

regards
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Forced Mate #34

Post by MikeGL »

MikeGL wrote:
Vinvin wrote:
MikeGL wrote:Published as Mate in #34. Source ChestUCI.epd position: 6246
[d]R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1
White to Play, Mate in #34

According to engines, there are many other possible winning lines by
activating white K via g2 and then attacking blacks position.
But haven't verified if that idea would mate longer or shorter.

Possible correct solution below follows:
This solution is quite artistic because the position of black crumbles by
just maneuvering whites king to a1 and back to h1. The idea is to lose tempo so
white has the possibility to checkmate via Rb8-Rb1-Rg1-Rg7-Rh7# checkmate.
SF-MF after 17h30m :

Code: Select all

FEN: R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1

Stockfish_170708_matefinder:
...
---------------------------------------------------------------------------
 50/94	7:17:22	437 679 782k	16 678k	+7,78	1.Kg1 c6 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 Kxh6 8.Ne2 Bc5 9.f4 Ne7 10.d4 Bb6 11.d5 Kg6 12.c7 Nec8 13.e5 Bxc7 14.d6 Nxd6 15.exd6 Nb5 16.dxc7 Nxc7 17.Ra7 Nd5 18.Rxa6+ Kf7 19.Rxa3 Ne3+ 20.Kh3 Nxc2 21.Rxc3 Nb4 22.Kxh4 Nd5 23.Rd3 Ne7 24.Nc3 Nc6 25.Kg4 Ke6 26.Ne4 Kf7 27.Rd2 Ne7 28.Rd7 Ke6 29.Ra7 Kf7 30.Kg3
 50/94	7:17:22	437 679 782k	16 678k	+50,13	1.Kg2 c6 2.dxc6 Bd8 3.Nd5 Kh7 4.Kh3 Ba5 5.Ne7 Bd8 6.Nxc8 Nxc6 7.Nxd6 Bg5 8.Nf7 Bxh6 9.Nxh6 Nb4 10.Nf7 Nxc2 11.Rxa6 Kg7 12.Nd6 Nb4 13.Rxa3 Nd5 14.Ra5 Nb4 15.Kxh4 Kf8 16.Rc5 Nxa2 17.Ne4 Nc1 18.Rc8+ Kg7 19.Rc7+ Kg6 20.Nxc3 Nb3 21.Ne4 Kh6 22.Rc6+ Kg7 23.Rc3 Na5 24.Rc7+ Kg6 25.Rc5 Nb3 26.Rb5 Na1 27.Rb6+ Kf7 28.Nc3 Nc2 29.Kxh5 Kg7 30.Rb3 Na1 31.Rb7+ Kf8 32.Rb6 Kf7 33.Nd5 Ke8 34.Rb1
 50/94	7:17:22	437 679 782k	16 678k	+58,04	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Nxf8 14.Rxf8 Kxh6 15.Rf7 Kg6 16.Rxc7 Kf6 17.Rxc3 Ke5 18.Rxa3 Kxd5 19.Rxa6 Ke6 20.Ra4 Kd7 21.Rh4 d5 22.Rxh5 Kc6 23.Rxh3 Kc5 24.Rh4 d4 25.Rh5+ Kc6 26.Rh3 Kb6 27.Rb3+ Kc6 28.Rd3 Kc5 29.Ra3 Kd6 30.Rh3 Kd5
---------------------------------------------------------------------------
 51/94	12:51:05	778 099 061k	16 818k	+7,75	1.Kg1 c5 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 h3+ 8.Nxh3 Kxh6 9.Nf4 Nxc6 10.Rxc8 Nb4 11.Ne2 Bg7 12.Nxc3 Nxc2 13.Nd5 Ne1+ 14.Kf1 Nxd3 15.Ke2 Ne5 16.f4 Ng6 17.Rc6 Kh7 18.f5 Ne5 19.Rxa6 Bf8 20.Ra7+ Kh6 21.Nf4 Ng4 22.h4 Ne5 23.Ra6+ Kh7 24.Ne6 Bb4 25.Ng5+ Kg8 26.Ra8+ Kg7 27.Ra7+ Kg8 28.Ne6 Nc6 29.Rg7+ Kh8 30.Rc7 Ne5 31.Ke3 Ng4+ 32.Kf3 Ne5+ 33.Kf4 Bd6 34.Rc8+ Kh7 35.f6
 51/94	12:51:05	778 099 061k	16 818k	+53,19	1.Kg2 c6 2.dxc6 d5 3.Kh3 Bd8 4.Nxd5 Kh7 5.c7 Bxc7 6.Nxc7 Kxh6 7.Nd5 Kg6 8.e4 Nd6 9.Rxa7 Nxe4 10.Kxh4 a5 11.Rxa5 Kf7 12.Ra7+ Ke6 13.Re7+ Kxd5 14.Rxe4 Kxe4 15.Kxh5 Kf4 16.Kh4 Kf5 17.Kg3 Ke4 18.Kg4 Ke5 19.f4+ Ke4 20.f5 Ke3 21.Kh5 Kd2 22.f6 Kxc2 23.f7 Kd2 24.f8Q c2 25.Qxa3 c1Q 26.Qxc1+ Kxc1 27.Kg6 Kd2 28.h4 Ke3 29.h5 Kf4 30.h6 Kg4 31.h7 Kh3
 51/94	12:51:05	778 099 061k	16 818k	+58,04	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Nxf8 14.Rxf8 Kxh6 15.Rf7 Kg6 16.Rxc7 Kf6 17.Rxc3 Ke5 18.Rxa3 Kxd5 19.Rxa6 Ke6 20.Ra5 d5 21.Ra6+ Ke7 22.Rh6 Kd7 23.Rh7+ Kc6 24.Rxh5 Kc5 25.Rxh3 Kb4 26.Rh7 Kc5 27.Rh5 Kd6 28.Rh6+ Ke5 29.Rh4 Kf6 30.Rg4 d4 31.Rxd4 Kg7 32.Rg4+ Kf7 33.Rf4+ Kg6 34.Ra4 Kf5 35.Ra3 Kf6 36.Rf3+ Kg6 37.a4 Kh5
---------------------------------------------------------------------------
 51/94	13:04:13	793 308 559k	16 860k	+7,75	1.Kg1 c5 2.dxc6 d5 3.Kg2 d4 4.e4 d3 5.exd3 Bd4 6.Nxh5 Kh7 7.Nf4 h3+ 8.Nxh3 Kxh6 9.Nf4 Nxc6 10.Rxc8 Nb4 11.Ne2 Bg7 12.Nxc3 Nxc2 13.Nd5 Ne1+ 14.Kf1 Nxd3 15.Ke2 Ne5 16.f4 Ng6 17.Rc6 Kh7 18.f5 Ne5 19.Rxa6 Bf8 20.Ra7+ Kh6 21.Nf4 Ng4 22.h4 Ne5 23.Ra6+ Kh7 24.Ne6 Bb4 25.Ng5+ Kg8 26.Ra8+ Kg7 27.Ra7+ Kg8 28.Ne6 Nc6 29.Rg7+ Kh8 30.Rc7 Ne5 31.Ke3 Ng4+ 32.Kf3 Ne5+ 33.Kf4 Bd6 34.Rc8+ Kh7 35.f6
 51/94	13:04:13	793 308 559k	16 860k	+53,19	1.Kg2 c6 2.dxc6 d5 3.Kh3 Bd8 4.Nxd5 Kh7 5.c7 Bxc7 6.Nxc7 Kxh6 7.Nd5 Kg6 8.e4 Nd6 9.Rxa7 Nxe4 10.Kxh4 a5 11.Rxa5 Kf7 12.Ra7+ Ke6 13.Re7+ Kxd5 14.Rxe4 Kxe4 15.Kxh5 Kf4 16.Kh4 Kf5 17.Kg3 Ke4 18.Kg4 Ke5 19.f4+ Ke4 20.f5 Ke3 21.Kh5 Kd2 22.f6 Kxc2 23.f7 Kd2 24.f8Q c2 25.Qxa3 c1Q 26.Qxc1+ Kxc1 27.Kg6 Kd2 28.h4 Ke3 29.h5 Kf4 30.h6 Kg4 31.h7 Kh3
 52/94	13:04:13	793 308 559k	16 860k	+M41	1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Kxh6 14.Nxd7 Kg6 15.Rc4 Kf5 16.Rxc7 Ke4 17.Nb6 Kd4 18.Rc4+ Ke5 19.Rxc3 Kd4 20.Rc4+ Ke5 21.Ra4 Kf5 22.Rxa6 Ke5 23.Ra4 Kf6 24.Rxa3 Ke7 25.Ra6 Kf7 26.Nc4 Kf6 27.Ra7 Kf5 28.Ra5 Ke4 29.Nxd6+ Kf4 30.Ne4 Kxe4 31.d6 Kd4 32.Rxh5 Ke3 33.d7 Kd2 34.d8Q+ Kc3 35.Rxh3+ Kb4
Thanks for that more than 17hr of position-crunching on your
powerful hardware.

But I am not sure if you just found out and uncovered a cook for this mate puzzle or whether SF-MF missed the #M34 because it played 4.f4 which
untangles the pieces of black and gives black a bit of resistance against
#M34.


52/94 13:04:13 793 308 559k 16 860k +M41 1.Rb8 h3 2.Kg1 Bc5 3.Kf1 Bb6 4.f4 Bxe3 5.Rb4 Ne7 6.Re4 Bd4 7.Rxd4 Ng8 8.Nxg8 Kxg8 9.f5 Nc8 10.f6 Nb6 11.Rf4 Kh7 12.f7 Nd7 13.f8N+ Kxh6 14.Nxd7 Kg6 15.Rc4 Kf5 16.Rxc7 Ke4 17.Nb6 Kd4 18.Rc4+ Ke5 19.Rxc3 Kd4 20.Rc4+ Ke5 21.Ra4 Kf5 22.Rxa6 Ke5 23.Ra4 Kf6 24.Rxa3 Ke7 25.Ra6 Kf7 26.Nc4 Kf6 27.Ra7 Kf5 28.Ra5 Ke4 29.Nxd6+ Kf4 30.Ne4 Kxe4 31.d6 Kd4 32.Rxh5 Ke3 33.d7 Kd2 34.d8Q+ Kc3 35.Rxh3+ Kb4


Because if 4.f4 on above variation is not played, the Bb6 > 4...Bxe3 >
6...Bd4 is not possible and cannot harass the Nf6 which is already
positioned for the planned checkmate.

But anyway, below is #M40 from yacpdb site but solution was not provided there.

[d]2B2bk1/p1p1p1p1/2P1P1Pp/p1P5/2P4p/Pp5P/bP1K4/8 w - - 0 1
Source yacpdb.org /published as #M40

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.10"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[BlackElo "2400"]
[TimeControl "0+2"]
[SetUp "1"]
[FEN "2B2bk1/p1p1p1p1/2P1P1Pp/p1P5/2P4p/Pp5P/bP1K4/8 w - - 0 1"]
[Termination "normal"]
[PlyCount "79"]
[WhiteType "human"]
[BlackType "human"]

1. Kc1 Kh8 2. Bd7 Kg8 3. Be8 Kh8 4. Bf7 h5 5. Be8 Kg8 6. Bd7 Kh8 7. Bc8 Kg8
8. Bb7 Kh8 9. Ba6 Kg8 10. Bc8 Kh8 11. Bd7 Kg8 12. Be8 Kh8 13. Bf7 a4 14.
Be8 Kg8 15. Bd7 Kh8 16. Bc8 Kg8 17. Ba6 Kh8 18. Bb5 Kg8 19. Bxa4 a6 20. Bb5
a5 21. Ba6 Kh8 22. Bb7 Kg8 23. Bc8 Kh8 24. Bd7 Kg8 25. Be8 Kh8 26. Bf7 a4
27. Be8 Kg8 28. Bd7 Kh8 29. Bc8 Kg8 30. Ba6 Kh8 31. Bb5 Kg8 32. Bxa4 Kh8
33. Bb5 Kg8 34. a4 Kh8 35. a5 Bb1 36. Kxb1 Kg8 37. a6 Kh8 38. a7 Kg8 39.
a8=Q Kh8 40. Qxf8# 1-0
[/pgn]

Puzzle not yet in Arpad's post from previous page of this thread,
I can't find solution anywhere else.

regards

Oops sorry :oops:, should have used the [Preview] button properly before posting.
I missed the closing double quotes of the PGN tag [Site "Talkchess"] and strange things happened, displaying chess pieces instead of the complete game.

Corrected PGN tag and puzzle solution of my previous post follows,

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.10"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[BlackElo "2400"]
[TimeControl "0+2"]
[SetUp "1"]
[FEN "2B2bk1/p1p1p1p1/2P1P1Pp/p1P5/2P4p/Pp5P/bP1K4/8 w - - 0 1"]
[Termination "normal"]
[PlyCount "79"]
[WhiteType "human"]
[BlackType "human"]

1. Kc1 Kh8 2. Bd7 Kg8 3. Be8 Kh8 4. Bf7 h5 5. Be8 Kg8 6. Bd7 Kh8 7. Bc8 Kg8
8. Bb7 Kh8 9. Ba6 Kg8 10. Bc8 Kh8 11. Bd7 Kg8 12. Be8 Kh8 13. Bf7 a4 14.
Be8 Kg8 15. Bd7 Kh8 16. Bc8 Kg8 17. Ba6 Kh8 18. Bb5 Kg8 19. Bxa4 a6 20. Bb5
a5 21. Ba6 Kh8 22. Bb7 Kg8 23. Bc8 Kh8 24. Bd7 Kg8 25. Be8 Kh8 26. Bf7 a4
27. Be8 Kg8 28. Bd7 Kh8 29. Bc8 Kg8 30. Ba6 Kh8 31. Bb5 Kg8 32. Bxa4 Kh8
33. Bb5 Kg8 34. a4 Kh8 35. a5 Bb1 36. Kxb1 Kg8 37. a6 Kh8 38. a7 Kg8 39.
a8=Q Kh8 40. Qxf8# 1-0
[/pgn]

Editing of previous post not allowed after 15 minutes.
But I guess it would be better if there's [pgn] cleaner before posting to
avoid that bug on previous post. : )

regards
User avatar
Nordlandia
Posts: 2821
Joined: Fri Sep 25, 2015 9:38 pm
Location: Sortland, Norway

Re: Forced Mate #34

Post by Nordlandia »

Post can't be edited after 15 minutes time.

Why exactly 15min?
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Forced Mate #28 /ChestUCI.epd position 6185

Post by MikeGL »

Nordlandia wrote:Post can't be edited after 15 minutes time.

Why exactly 15min?
I could be wrong, but I think that was implemented during the rise of Rybka
and then the rise of Houdini, where heated debate, allegations and counter-allegations almost set the whole forum on fire.
Allowing to modify a post after more than 15 minutes would allow some posters to delete their deeply held secrets which were posted at the heat of discussions. ; )

But never mind, here's a Mate in #28.

[d]8/p6p/8/4p2p/N2P4/pp4pP/kp3bK1/qn3N1R w - - 0 1
White to Play, Mate in 28
Source ChestUCI.epd position: 6185

Possible solution follows,
.
.
.

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.07"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[BlackElo "2400"]
[Time "18:25:26"]
[WhiteElo "2400"]
[TimeControl "0+2"]
[SetUp "1"]
[FEN "8/p6p/8/4p2p/N2P4/pp4pP/kp3bK1/qn3N1R w - - 0 1"]
[Termination "normal"]
[PlyCount "55"]
[WhiteType "human"]
[BlackType "human"]
[Comment "bm #28;"]

1. Nd2 exd4 2. Ne4 Be3 3. Rd1 h4 4. Rd3 Bg1 (4. .. Bf2 5. Rd2 Be3 6. Rd1
{Transposes to main line}) 5. Rd2 Be3 6. Rd1 Bf2 7. Rd3 Bg1 8. Rf3 (8.
Kxg1? Nd2+ 9. Kg2 Qf1#) 8. .. a6 9. Rf1 Be3 10. Rd1 Bf2 11. Rd3 Bg1 12. Rf3
a5 13. Rf1 Be3 (13. .. Bf2? 14. Rxf2 {#M6 +-}) 14. Rd1 Bf2 15. Rd3 Bg1 16.
Rf3 h6 17. Rf1 Be3 18. Rd1 Bf2 19. Rd3 Bg1 20. Rf3 h5 21. Rf1 Be3 22. Rd1
Bf2 23. Rd3 Bg1 24. Rf3 Bh2 25. Rf1 Bg1 26. Rxg1 d3 27. Nec3+ Nxc3 28.
Nxc3# 1-0
[/pgn]

This is a strange triangulation version of a rook and losing or gaining of tempo by
restricting the possible moves of the only active piece of black, the dark- squared-bishop
Solution not found anywhere else.

regards
Last edited by MikeGL on Wed Jul 12, 2017 1:32 am, edited 1 time in total.
duncan
Posts: 12038
Joined: Mon Jul 07, 2008 10:50 pm

Re: Old theme -Forced Mate#66 source ChestUCI.epd position

Post by duncan »

MikeGL wrote:[D]8/p1p3p1/p5Pp/8/p1p5/6r1/1QP2p1k/N4Kb1 w - - 0 1

White to Play, Mate in #66 source ChestUCI.epd position 6351

Same old theme by Bláthy, but same old difficult puzzle for
most engines due to zugzwangs.
Not found in yacpdb and not in one of Arpad Rusz posted puzzle/solutions.

Solution of above puzzle follows -
I tried this out on a computer, it won faster than 66. is the computer overlooking something ?