Nice study by Troitsky

Ajedrecista · Post by **Ajedrecista** » Thu Mar 30, 2023 4:08 pm

Hello Andrew:

acase wrote: ↑Thu Mar 30, 2023 4:37 amPerhaps your engines will find this one a little more challenging, I worked on it at my job during my lunch.

Give this one a try
White to play and win
[pgn][Event "Computer chess game"]
[Site "WORKSTATION-PC"]
[Date "2023.03.29"]
[Round "?"]
[White "Stockfish"]
[Black "Stockfish"]
[Result "*"]
[BlackElo "2000"]
[Time "22:14:41"]
[WhiteElo "3600"]
[TimeControl "none"]
[SetUp "1"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[Termination "unterminated"]
[PlyCount "0"]
[WhiteType "human"]
[BlackType "human"]

*[/pgn]

I have not got access to engine analysis right now, but the plan could be the following? Capture the black bishop on b6 square to protect the white rook on e3 square; if black recaptures on b6, then Ng3 protecting both f4 and h4 white pawns, blocking the black king; then Ba2 and Bb2 to allow the white king go to f2 square and finally Rg3#. I do not know if black has other resources, like not recapturing on b6 and try 1.- ..., Kxf4 or 1.- ..., Kxh4.

This plan is greatly based in a similar problem from 1904:

https://pdb.dieschwalbe.de/P1038291

Is my plan cooked?

Regards from Spain.

Ajedrecista.

acase · Post by **acase** » Thu Mar 30, 2023 4:30 pm

Ajedrecista wrote: ↑Thu Mar 30, 2023 4:08 pm Hello Andrew:

acase wrote: ↑Thu Mar 30, 2023 4:37 amPerhaps your engines will find this one a little more challenging, I worked on it at my job during my lunch.

Give this one a try
White to play and win
[pgn][Event "Computer chess game"]
[Site "WORKSTATION-PC"]
[Date "2023.03.29"]
[Round "?"]
[White "Stockfish"]
[Black "Stockfish"]
[Result "*"]
[BlackElo "2000"]
[Time "22:14:41"]
[WhiteElo "3600"]
[TimeControl "none"]
[SetUp "1"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[Termination "unterminated"]
[PlyCount "0"]
[WhiteType "human"]
[BlackType "human"]

*[/pgn]
I have not got access to engine analysis right now, but the plan could be the following? Capture the black bishop on b6 square to protect the white rook on e3 square; if black recaptures on b6, then Ng3 protecting both f4 and h4 white pawns, blocking the black king; then Ba2 and Bb2 to allow the white king go to f2 square and finally Rg3#. I do not know if black has other resources, like not recapturing on b6 and try 1.- ..., Kxf4 or 1.- ..., Kxh4.

This plan is greatly based in a similar problem from 1904:

https://pdb.dieschwalbe.de/P1038291

Is my plan cooked?

Regards from Spain.

Ajedrecista.

Hi Jesus,

You're on the right track, and that is indeed the hilarious (to me at least) problem it is based upon. I think it might have been a little bit more tricky if I put the white king on a2, although the solution would still be basically the same.

acase · Post by **acase** » Thu Mar 30, 2023 5:46 pm

Stockfish seems to think there is a win here....for black

Code: Select all

FEN: RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1

Stockfish_23022721_x64_bmi2:
NNUE evaluation using nn-52471d67216a.nnue enabled
 1/1	00:00	 8k	2,642k	-3.57	1.Nc8xb6 Bc6xa8 2.Nb6xa8 Kg4xh4
 2/2	00:00	 9k	2,969k	-3.59	1.Nc8xb6 Bc6xa8 2.Nb6xa8
 3/3	00:00	 9k	3,159k	-2.64	1.Nc8xb6 Bc6xa8 2.Qb8xc7
 4/4	00:00	 10k	3,369k	-2.54	1.Nc8xb6 Bc6xa8 2.Nb6xc4
 5/4	00:00	 11k	3,608k	-1.59	1.Nc8xb6 Bc6xa8 2.Nb6xc4
 6/4	00:00	 11k	3,771k	-1.74	1.Nc8xb6 Bc6xa8 2.Nb6xc4
 7/6	00:00	 18k	4,434k	-1.81	1.Nc8xb6 c7xb6 2.Qb8xb6 Re6-d6 3.Ra8-b8 Kg4xh4
 8/8	00:00	 39k	7,874k	-1.27	1.Nc8xb6 Re6-f6 2.Nb6xc4 b5xc4
 9/8	00:00	 115k	12,774k	-0.97	1.Nc8xb6 Re6-g6 2.Qb8xc7 Bc6xa8
 10/9	00:00	 234k	14,614k	-0.75	1.Nc8xb6 Re6-e7 2.Nb6-c8 Re7-h7 3.Ra8-a6 Nf8-d7 4.Qb8xc7
 11/12	00:00	 467k	16,676k	-0.57	1.Nc8xb6 Qg8-g7 2.Ra8-a7 Re6-g6 3.Qb8xc7 Qg7xc7
 12/15	00:00	 739k	17,186k	-0.50	1.Nc8xb6 c7xb6 2.Qb8xb6 Bc6xa8 3.Qb6xb5 Ba8-c6 4.Qb5xc4 Re6-d6 5.Qc4-c5
 13/15	00:00	 820k	17,089k	-0.50	1.Nc8xb6 c7xb6 2.Qb8xb6 Bc6xa8 3.Qb6xb5 Nf8-g6 4.Qb5xc4 Qg8-c8 5.Qc4-d4 Rh8-d8 6.Qd4-g7 Rd8-g8
 14/21	00:00	 2,028k	17,788k	-0.70	1.Nc8xb6 c7xb6 2.Qb8xb6 Bc6xa8 3.Qb6xb5 Nf8-g6 4.Bb1-c2 Ng6xh4 5.Qb5xc4 Nh4-f3 6.Bc2-d1 h5-h4 7.Qc4-d4 h4-h3 8.Bd1xf3+ e4xf3 9.Re3xe6
 15/23	00:00	 2,345k	17,898k	-0.75	1.Nc8xb6 c7xb6 2.Qb8xb6 Bc6xa8 3.Qb6xb5 Nf8-g6 4.Bb1-c2 Ng6xh4 5.Qb5xc4 Re6-d6 6.Bc2-d1+ Nh4-f3 7.Qc4-c5 Qg8-d5 8.Qc5-a7
 16/24	00:00	 3,103k	17,936k	-0.20	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ne1xc2 Re6-e8 4.Qb8xb6 Bc6xa8 5.Re3-e1 e4-e3 6.Re1-g1+ Kg4-h3
 17/25	00:00	 6,586k	17,516k	-0.46	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Qb8xa8 Nf8-g6 4.Qa8-d5 Re6-f6 5.Qd5xb5 Ng6xh4 6.Ng2xh4 Kg4xh4 7.Re3-e1 Kh4-h3 8.Qb5-e5 Rf6-f8 9.b4-b5 Kh3-g2 10.Re1-g1+ Kg2xg1
 18/25	00:00	 8,554k	17,565k	 0.00	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Re3-e1 e4-e3 4.Qb8xa8 Nf8-g6 5.Qa8-d5 e3xd2 6.Re1-g1 d2xc1Q 7.Ng2-e3+ Kg4xf4 8.Ne3-g2+ Kf4-g3
 19/24	00:00	 9,530k	17,550k	 0.00	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Re3-e1 Nf8-g6 4.Ng2-e3+ Kg4-h3 5.Re1-h1+ Kh3-g3 6.Qb8-a7 Qg8-h7 7.Rh1-g1+ Kg3-h3 8.Qa7-a6 Ng6xh4 9.Qa6xb5 Re6-e8 10.Rg1-h1+ Kh3-g3 11.Rh1-g1+ Kg3-h3
 20/21	00:00	 10,898k	17,663k	 0.00	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Re3-e1 Nf8-g6 4.Ng2-e3+ Kg4-h3 5.Qb8-a7 Qg8-h7 6.Re1-h1+ Kh3-g3 7.Rh1-g1+ Kg3-h3 8.Rg1-h1+
 21/15	00:00	 11,200k	17,721k	 0.00	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Re3-e1 Nf8-g6 4.Ng2-e3+ Kg4-h3 5.Qb8-a7 Qg8-h7 6.Re1-h1+ Kh3-g3 7.Rh1-g1+ Kg3-h3
 22/36	00:01	 23,205k	17,113k	-0.26	1.Nc8xb6 c7xb6 2.Qb8xb6 Bc6xa8 3.Qb6xb5 Nf8-g6 4.Ne1-g2 Ba8-c6 5.Qb5-c5 Ng6xh4 6.Ng2xh4 Kg4xh4 7.b4-b5 Bc6-a8 8.Qc5xf5 Qg8-g4 9.Qf5-c5 Re6-e8 10.Qc5xc4 Qg4-d1 11.Qc4-d4 Rh8-f8 12.Qd4-d7 Qd1-g4 13.f4-f5 Qg4xf5 14.Qd7-d6 Qf5-e5 15.Qd6-d7 Re8-e7 16.Qd7-h3+ Kh4-g5 17.Re3-g3+ Kg5-h6
 23/39	00:03	 50,656k	16,812k	-0.15	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Qb8xa8 Re6-g6 4.Qa8-b8 Nf8-d7 5.Qb8-b7 Nd7-b8 6.Re3-e1 Kg4-h3 7.Ng2-e3 Rg6-g1 8.Re1xg1 Qg8xg1 9.Bc1-b2 Rh8-g8 10.Qb7-d5 Rg8-f8 11.Ne3xf5 Rf8xf5 12.Qd5xf5+ Kh3-h2 13.Qf5xe4 Qg1-g3 14.Qe4-f5 Qg3-e1 15.Qf5xh5 Qe1xd2 16.Qh5xb5 Qd2-e1
 24/43-	00:03	 52,378k	16,815k	-0.19	1.Nc8xb6 c7xb6
 24/43-	00:03	 54,009k	16,831k	-0.22	1.Nc8xb6 c7xb6
 24/47-	00:04	 80,799k	16,904k	-0.56	1.Nc8xb6 c7xb6
 24/47+	00:04	 81,645k	16,914k	-0.47	1.Nc8xb6
 24/47+	00:04	 81,902k	16,915k	-0.29	1.Nc8xb6
 24/54	00:04	 82,953k	16,915k	-0.21	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Qb8xa8 Re6-g6 4.Qa8-b8 Nf8-e6 5.Qb8-e5 Qg8-b8 6.Qe5xb5 Ne6xf4 7.Ng2xf4 Qb8xf4 8.Qb5xc4 Rh8-g8 9.Bb1xd3 Kg4xh4 10.Bd3xe4 Rg6-g1 11.Qc4-e2 Rg8-g3 12.Ka1-b2 Qf4-f1 13.Qe2xf1 Rg1xf1 14.Be4-d3 Rg3xe3 15.d2xe3 Rf1-f2+ 16.Kb2-b1 Kh4-g5 17.c3-c4 h5-h4 18.c4-c5 b6xc5 19.b4xc5 Kg5-f6 20.Bc1-b2+ Kf6-e6 21.Bd3-c4+ Ke6-e7 22.Bb2-e5 h4-h3 23.Be5-d6+ Ke7-f6 24.Bc4-b5 h3-h2 25.Bd6xh2 Rf2xh2 26.c5-c6 Rh2-h7 27.Kb1-c2 Kf6-e6
 25/35+	00:05	 85,833k	16,906k	-0.23	1.Nc8xb6
 25/38-	00:05	 87,037k	16,900k	-0.28	1.Nc8xb6 c7xb6
 25/44+	00:05	 88,306k	16,897k	-0.24	1.Nc8xb6
 25/44+	00:05	 90,149k	16,920k	-0.13	1.Nc8xb6
 25/46-	00:05	 90,788k	16,925k	-0.31	1.Nc8xb6 c7xb6
 25/49-	00:05	 98,682k	16,869k	-0.42	1.Nc8xb6 c7xb6
 25/49+	00:05	 100,033k	16,852k	-0.30	1.Nc8xb6
 25/57+	00:06	 101,861k	16,839k	-0.12	1.Nc8xb6
 25/57	00:06	 104,684k	16,822k	-0.08	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Qb8xa8 Re6-g6 4.Qa8-b8 Nf8-e6 5.Qb8-e5 Qg8-b8 6.Qe5xb5 Ne6xf4 7.Ng2xf4 Qb8xf4 8.Qb5xc4 Rh8-g8 9.Bb1xd3 Kg4xh4 10.Bd3xe4 Rg6-g1 11.Qc4-e2 Qf4-f1 12.Qe2-h2+ Kh4-g5 13.Re3-g3+ Kg5-h6 14.Rg3xg1 Rg8xg1 15.Be4-b1 b6-b5 16.Qh2-d6+ Kh6-g5 17.Qd6-e7+ Kg5-g4 18.Qe7-h7 h5-h4 19.Qh7-g6+ Kg4-h3 20.Qg6xf5+ Qf1xf5 21.Bb1xf5+ Kh3-g3
 26/42-	00:06	 108,493k	16,704k	-0.14	1.Nc8xb6 c7xb6
 26/42-	00:06	 109,308k	16,704k	-0.17	1.Nc8xb6 c7xb6
 26/54-	00:07	 118,967k	16,681k	-0.31	1.Nc8xb6 c7xb6
 26/54+	00:07	 124,263k	16,657k	-0.26	1.Nc8xb6
 26/68-	00:08	 135,838k	16,572k	-0.40	1.Nc8xb6 c7xb6
 26/68	00:08	 148,327k	16,490k	-0.40	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Rh8-h7 7.Re3-e1 Nd7-f6 8.Nc2-e3+ Kg4xh4 9.Re1-h1+ Kh4-g3 10.Ne3xf5+ Kg3-g4 11.Nf5-e3+ Kg4xf4 12.Rh1-f1+ Kf4-e5 13.Rf1-f5+ Ke5-d6 14.Rc7xh7 Nf6xh7 15.Rf5xh5 Nh7-f6 16.Rh5-g5 Nf6-e8 17.Ne3-f5+ Kd6-c7 18.Nf5-g7 Re6-f6 19.Ng7xe8+ Bc6xe8 20.Rg5-g7+ Be8-f7 21.Ka1-b1 Kc7-d6 22.Rg7-g1 Rf6-f3
 27/44-	00:09	 159,180k	16,460k	-0.41	1.Nc8xb6 c7xb6
 27/44-	00:09	 162,787k	16,460k	-0.44	1.Nc8xb6 c7xb6
 27/49-	00:10	 179,291k	16,505k	-0.53	1.Nc8xb6 c7xb6
 27/49+	00:11	 182,160k	16,501k	-0.48	1.Nc8xb6
 27/49+	00:11	 184,966k	16,497k	-0.39	1.Nc8xb6
 27/49	00:11	 191,162k	16,481k	-0.48	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Rh8-h6 7.Re3-e2 Re6-d6 8.Re2-e1 Rd6-d3 9.Re1-g1+ Kg4xf4 10.Rg1-f1+ Rd3-f3 11.Rf1-g1 Rh6-d6 12.Nc2-d4 Bc6-d5 13.Nd4xf3 Kf4xf3 14.Rg1-f1+ Kf3-e2 15.Rf1xf5
 28/47-	00:12	 203,254k	16,470k	-0.49	1.Nc8xb6 c7xb6
 28/47-	00:12	 208,871k	16,492k	-0.52	1.Nc8xb6 c7xb6
 28/47-	00:19	 313,408k	16,452k	-0.80	1.Nc8xb6 c7xb6
 28/47+	00:19	 314,548k	16,455k	-0.72	1.Nc8xb6
 28/48+	00:19	 320,346k	16,463k	-0.55	1.Nc8xb6
 28/48	00:20	 339,606k	16,476k	-0.71	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Rh8-h6 7.Ka1-b2 Nd7-f6 8.Rc7-g7+ Kg4xf4 9.d2-d3 Nf6-g4 10.Re3xe4+ Kf4-g3 11.Bc1-f4+ Kg3-h3 12.Re4xe6 Rh6xe6 13.Nc2-d4 Re6-e1 14.Nd4xc6 Re1-f1 15.Bf4-g5 Rf1-f2+ 16.Kb2-b1 c4xd3 17.Rg7-d7 Rf2-f1+ 18.Kb1-b2
 29/43-	00:21	 348,780k	16,478k	-0.71	1.Nc8xb6 c7xb6
 29/43+	00:21	 353,501k	16,476k	-0.68	1.Nc8xb6
 29/43-	00:21	 354,787k	16,478k	-0.75	1.Nc8xb6 c7xb6
 29/49-	00:22	 374,066k	16,486k	-0.81	1.Nc8xb6 c7xb6
 29/52+	00:23	 394,563k	16,517k	-0.74	1.Nc8xb6
 29/52	00:25	 419,499k	16,553k	-0.88	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Rh8-h6 7.Re3-e2 Kg4xh4 8.Re2-e1 Re6-f6 9.Nc2-d4 Nd7-f8 10.Rc7-e7 Nf8-g6 11.Re7-g7 Kh4-h3 12.Re1-g1 e4-e3 13.Rg1-g5 h5-h4 14.d2xe3 Bc6-e4 15.Bc1-d2 Rf6-d6 16.Bd2-e1 Ng6-f8 17.Rg7-e7 Rd6-g6
 30/49+	00:26	 434,600k	16,566k	-0.79	1.Nc8xb6
 30/50+	00:26	 435,308k	16,568k	-0.75	1.Nc8xb6
 30/50+	00:26	 442,225k	16,581k	-0.53	1.Nc8xb6
 30/50	00:26	 444,335k	16,583k	-0.48	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Rh8-h6 7.Re3-e1 e4-e3 8.Nc2xe3+ Re6xe3 9.Re1xe3 Rh6-d6 10.Re3-e8 Kg4xh4 11.Re8-c8 Bc6-d5 12.Rc8-d8 Bd5-e6 13.Rd8-h8 Nd7-f6 14.Rc7-g7 Nf6-e4 15.Rg7-g6 Be6-f7 16.Rg6xd6 Ne4xd6 17.Rh8-d8 Nd6-e4 18.Rd8-f8 Bf7-e6 19.Rf8-e8 Be6-d7 20.Re8-e7 Bd7-c6 21.Re7-e6 Bc6-a8 22.Re6-e8 Ba8-b7
 31/52-	00:27	 452,194k	16,588k	-0.54	1.Nc8xb6 c7xb6
 31/52-	00:29	 487,548k	16,552k	-0.57	1.Nc8xb6 c7xb6
 31/53-	00:29	 496,391k	16,552k	-0.62	1.Nc8xb6 c7xb6
 31/53+	00:30	 502,778k	16,544k	-0.58	1.Nc8xb6
 31/53+	00:30	 507,516k	16,538k	-0.50	1.Nc8xb6
 31/53	00:31	 518,421k	16,512k	-0.63	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Rh8-h6 7.Re3-e1 e4-e3 8.Nc2xe3+ Re6xe3 9.Re1xe3 Rh6-d6 10.Re3-e8 Kg4xh4 11.Re8-c8 Bc6-d5 12.Rc8-d8 Bd5-e6 13.Rd8-h8 Nd7-f6 14.Rc7-g7 Nf6-e4 15.Rh8-h6 Be6-f7 16.Rh6xd6 Ne4xd6 17.Ka1-b2 Kh4-h3 18.Kb2-c2 Bf7-d5 19.d2-d3 c4xd3+ 20.Kc2xd3 Bd5-f3 21.Kd3-e3 Bf3-g4 22.Rg7-g6 Nd6-e4 23.c3-c4 Kh3-g2
 32/57+	00:32	 529,434k	16,480k	-0.57	1.Nc8xb6
 32/57-	00:33	 547,669k	16,433k	-0.63	1.Nc8xb6 c7xb6
 32/57-	00:51	 834,844k	16,315k	-1.06	1.Nc8xb6 c7xb6
 32/57+	00:55	 901,277k	16,305k	-0.95	1.Nc8xb6
 32/57	01:02	 1,024,685k	16,349k	-1.13	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-b8 5.Ne1xc2 Qb8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Kb1-b2 Nd7-f8 12.Rg1-h1+ Kh3-g3 13.Rh1-g1+ Kg3-f3 14.Rg1-f1+ Kf3-e2 15.Kb2-c2 h4-h3 16.Rc7-g7 Rh6-g6 17.Rg7-c7 h3-h2 18.Rf1-h1 Rg6-h6 19.Rc7-g7 Nf8-g6
 33/50	01:05	 1,072,439k	16,379k	-1.08	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-f2 21.Nd4-e6 Ne5-g4 22.Ne6-g5 Ng4-f6 23.Ng5-e6 Be8-d7
 34/26-	01:10	 1,148,693k	16,375k	-1.13	1.Nc8xb6 c7xb6
 34/40-	01:15	 1,231,378k	16,347k	-1.19	1.Nc8xb6 c7xb6
 34/50-	01:20	 1,314,583k	16,359k	-1.26	1.Nc8xb6 c7xb6
 34/50+	01:21	 1,327,010k	16,370k	-1.20	1.Nc8xb6
 34/63	01:21	 1,339,194k	16,374k	-1.24	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 Rh8-h6 10.Ka1-b2 h5-h4 11.Rc7-c8 Rf6-f8 12.Rg1-h1+ Kh3-g3 13.Rc8xf8 Nd7xf8 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-e1 21.Kb1-c2 Bd7-e8 22.Nd4-e6 Be8-h5 23.Ne6-f4 Bh5-d1+ 24.Kc2-b1 Ne5-d3 25.Nf4-g2+ Ke1-f2 26.Ng2-e3
 35/53	01:27	 1,426,088k	16,389k	-1.17	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-c8 5.Ne1xc2 Qc8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 Rh8-h6 10.Ka1-b2 h5-h4 11.Rc7-c8 Rf6-f8 12.Rg1-h1+ Kh3-g3 13.Rc8xf8 Nd7xf8 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Bd7-e8 21.Bc1-b2 Kf2-e1 22.Kb1-c2 Be8-h5 23.Bb2-c1 Bh5-e2 24.Nd4xb5 Be2-d3+ 25.Kc2-b2 Ke1-d1 26.f5-f6 Bd3-e2
 36/51-	01:38	 1,616,716k	16,414k	-1.25	1.Nc8xb6 c7xb6
 36/59-	01:44	 1,711,725k	16,416k	-1.30	1.Nc8xb6 c7xb6
 36/64-	02:06	 2,073,664k	16,431k	-1.38	1.Nc8xb6 c7xb6
 36/64+	02:07	 2,102,578k	16,445k	-1.31	1.Nc8xb6
 36/64-	02:29	 2,435,944k	16,344k	-1.48	1.Nc8xb6 c7xb6
 36/64+	02:30	 2,465,746k	16,355k	-1.33	1.Nc8xb6
 36/64	02:33	 2,505,376k	16,358k	-1.48	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Re6-f6 5.Ne1xc2 Qg8-d8 6.Re3-e1 Qd8xc7 7.Ra7xc7 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb2-c2 Kf2-e1 21.Nd4-e6 Be8-h5 22.Kc2-b1 Ke1-d1 23.Ne6-f4 Bh5-e8 24.Nf4-g2 Be8-d7 25.Ng2-e3+ Kd1-e2 26.Kb1-c2 Ne5-f3 27.f5-f6 Nf3-e5 28.Ne3-d5 Bd7-f5 29.Nd5-f4+ Ke2-e1
 37/49	02:38	 2,600,310k	16,369k	-1.48	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Re6-f6 5.Ne1xc2 Qg8-d8 6.Re3-e1 Qd8xc7 7.Ra7xc7 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 Rh8-h6 10.Ka1-b2 h5-h4 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb2-c2 Kf1-e1 21.Nd4-e6 Be8-h5 22.Ne6-d4 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2
 38/71	02:41	 2,649,635k	16,369k	-1.48	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-h4 20.Kb2-c2 Kf1-e1 21.Bc1-b2 Nh4-f3 22.Bb2-c1 Nf3-e5 23.Nd4-e6 Be8-h5 24.Ne6-d4 Bh5-g4 25.Kc2-b1 Ke1-d1 26.Nd4-c2 Bg4-h5 27.Nc2-e3+ Kd1-e2 28.Ne3-d5 Bh5-e8 29.Nd5-f4+ Ke2-d1 30.Nf4-g2 Be8-d7 31.Ng2-e3+ Kd1-e2 32.Kb1-c2 Ne5-f3 33.f5-f6 Bd7-e8 34.Ne3-g4 Be8-g6 35.Kc2-b2 Ke2-e1 36.Ng4-e3
 39/61-	03:24	 3,315,381k	16,220k	-1.56	1.Nc8xb6 c7xb6
 39/73	03:51	 3,753,061k	16,177k	-1.62	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-b8 5.Ne1xc2 Re6-f6 6.Re3-e1 Qb8xc7 7.Ra7xc7 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-e1 21.Kb1-c2 Be8-d7 22.Kc2-b1 Ne5-f3 23.Kb1-b2 Ke1-d1 24.Nd4-c2 Bd7-e8 25.Nc2-e3+ Kd1-e2 26.Ne3-g4 Be8-d7 27.f5-f6 Bd7-e8 28.Kb2-b1 Nf3-e1
 40/61+	03:54	 3,797,213k	16,179k	-1.50	1.Nc8xb6
 40/61+	03:59	 3,869,115k	16,153k	-1.42	1.Nc8xb6
 40/61+	04:00	 3,878,978k	16,152k	-1.31	1.Nc8xb6
 40/68	04:11	 4,057,883k	16,117k	-1.62	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-b8 5.Ne1xc2 Qb8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-e1 21.Kb1-c2 Be8-d7 22.Kc2-b1 Ke1-d1 23.Nd4-c2 Bd7-c6 24.Nc2-e3+ Kd1-e2 25.Ne3-g2 Bc6-e8 26.Kb1-c2 Be8-d7 27.Ng2-e3 Ne5-f3 28.Kc2-b2 Nf3-h4 29.f5-f6 Bd7-e6 30.Kb2-c2 Nh4-g6 31.Ne3-g2 Ke2-f3 32.Ng2-e3 Ng6-e5 33.Ne3-d1 Kf3-e2 34.Nd1-e3 Ne5-d7
 41/52-	04:22	 4,218,875k	16,082k	-1.61	1.Nc8xb6 c7xb6
 41/75+	04:32	 4,372,942k	16,064k	-1.53	1.Nc8xb6
 41/75	05:38	 5,362,080k	15,864k	-1.69	1.Nc8xb6 c7xb6 2.Qb8xb6 Bc6xa8 3.Qb6-d4 Ba8-c6 4.Bb1-c2 d3xc2 5.Ne1xc2 Kg4xh4 6.Qd4-d8+ Kh4-g4 7.Re3-e1 e4-e3 8.d2xe3 Bc6-g2 9.e3-e4 Re6xe4 10.Qd8-d1+ Kg4-g3 11.Nc2-e3 Nf8-e6 12.Re1-e2 Kg3-h2 13.Re2xg2+ Qg8xg2 14.Ne3xg2 Kh2xg2 15.Qd1-d2+ Kg2-g3 16.Qd2-d1 Ne6xf4 17.Bc1xf4+ Kg3xf4 18.Qd1-d6+ Kf4-f3 19.Qd6-f6 Rh8-e8 20.Qf6xf5+ Kf3-g3 21.Qf5-g6+ Kg3-f2 22.Qg6-f5+ Kf2-e1 23.Qf5xh5 Re4-e2 24.Qh5-h1+ Ke1-d2 25.Qh1-c1+ Kd2-d3 26.Qc1-b1+ Kd3xc3 27.Qb1-b2+ Kc3-d3 28.Qb2-b1+ Kd3-d4 29.Qb1-d1+ Kd4-c3 30.Qd1-c1+ Re2-c2 31.Qc1-g1 Rc2-d2 32.Qg1-c1+ Kc3-d3 33.Qc1-f1+ Re8-e2
 42/71	06:16	 5,951,587k	15,789k	-1.67	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rg1-h1+ Kh3-g3 13.Rc8xf8 Nd7xf8 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Bd7-e8 21.Kb1-c2 Kf2-e1 22.Nd4-e6 Be8-h5 23.Ne6-f4 Bh5-d1+ 24.Kc2-b1 Bd1-g4 25.Nf4-g2+ Ke1-e2 26.Ng2-e3 Bg4-h5 27.Kb1-b2 Bh5-e8 28.Kb2-c2 Be8-d7 29.Bc1-b2 Ne5-f3 30.f5-f6 Bd7-e6 31.Bb2-a1 Nf3-e5 32.Kc2-c1
 43/78-	08:10	 7,667,252k	15,630k	-1.75	1.Nc8xb6 c7xb6
 43/79-	09:31	 8,897,104k	15,564k	-1.84	1.Nc8xb6 c7xb6
 43/79	09:48	 9,162,574k	15,582k	-1.86	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rg1-h1+ Kh3-g3 13.Rc8xf8 Nd7xf8 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-e1 21.Kb1-c2 Bd7-e8 22.Nd4-e6 Be8-h5 23.Ne6-d4 Bh5-g4 24.Kc2-b1 Ke1-d1 25.Nd4-c2 Bg4-h5 26.Nc2-e3+ Kd1-e2 27.Kb1-b2 Bh5-e8 28.Kb2-b1 Be8-d7 29.Kb1-c2 Ne5-f3 30.Kc2-b2 Nf3-h4 31.f5-f6 Nh4-g6 32.Kb2-c2 Bd7-e6 33.Bc1-b2 Ng6-e5 34.Ne3-g2 Be6-f7 35.Ng2-e3 Bf7-g6 36.Bb2-c1
 44/79+	10:16	 9,595,072k	15,567k	-1.73	1.Nc8xb6
 44/79-	12:07	 11,283,437k	15,501k	-1.94	1.Nc8xb6 c7xb6
 44/79	14:44	 13,655,964k	15,434k	-2.01	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Qb8xa8 Re6-g6 4.Qa8-e8 Nf8-e6 5.Qe8-d7 Qg8-e8 6.Qd7-d5 Ne6xf4 7.Ng2xf4 Kg4xf4 8.Re3-e1 Rg6-g3 9.Qd5-d4 Rh8-g8 10.Bb1-c2 Rg3-f3 11.Qd4-d6+ Qe8-e5 12.Qd6xb6 Qe5-b8 13.Qb6-d4 d3xc2 14.d2-d3+ Kf4-g4 15.d3xe4 Qb8-h2 16.e4xf5+ Kg4-h3 17.Qd4-e4 Qh2-g3 18.f5-f6 Rg8-g4 19.Qe4-e2 Qg3-f2 20.Qe2-e5 Rg4-g1 21.Re1xg1 Qf2xg1 22.Ka1-b2 Qg1-g6 23.Qe5xb5 Kh3xh4 24.Qb5xc4+ Kh4-h3 25.Qc4-e6+ Qg6-f5 26.Qe6-e1 Rf3-f1 27.Qe1-e3+ Kh3-g2 28.Qe3-e2+ Rf1-f2 29.Qe2-c4 Qf5xf6 30.b4-b5 h5-h4 31.Qc4-g4+ Kg2-h2 32.Qg4-b4
 45/64-	17:44	 16,347,478k	15,352k	-2.08	1.Nc8xb6 c7xb6
 45/85	18:03	 16,624,315k	15,345k	-2.10	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-f2 21.Kb1-b2 Kf2-e1 22.Kb2-c2 Bd7-e8 23.Nd4-e6 Be8-h5 24.Ne6-f4 Bh5-d1+ 25.Kc2-b1 Bd1-g4 26.Nf4-g2+ Ke1-e2 27.Ng2-e3 Bg4-h5 28.Kb1-b2 Bh5-e8 29.Kb2-b1 Be8-d7 30.Kb1-c2 Ne5-f3 31.f5-f6 Nf3-e5 32.Bc1-b2 Bd7-e6 33.Ne3-g2 Be6-f7 34.Ng2-h4 Ne5-d7 35.Nh4-f5 Nd7xf6 36.Nf5-d4+ Ke2-e1 37.Nd4xb5 Nf6-g4 38.Nb5-d4 Bf7-g6 39.Kc2-c1 Ng4-e5 40.Nd4-c2+ Ke1-e2
 46/76	19:43	 18,091,854k	15,282k	-2.10	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-f2 21.Kb1-b2 Kf2-e1 22.Kb2-c2 Bd7-e8 23.Nd4-e6 Be8-h5 24.Ne6-f4 Bh5-d1+ 25.Kc2-b1 Bd1-g4 26.Nf4-g2+ Ke1-e2 27.Ng2-e3 Bg4-h5 28.Kb1-b2 Bh5-e8 29.Kb2-b1 Be8-d7 30.Kb1-c2 Ne5-f3 31.Kc2-b2 Nf3-h4 32.f5-f6 Nh4-g6 33.Kb2-c2 Bd7-e6 34.Bc1-b2 Ng6-e5 35.Ne3-g2 Be6-f7 36.Ng2-h4 Ke2-e1 37.Nh4-f5 Bf7-g6 38.f6-f7 Bg6xf7
 47/70	20:56	 19,170,173k	15,259k	-2.11	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf1-f2 21.Kb1-b2 Kf2-e1 22.Kb2-c2 Bd7-e8 23.Nd4-e6 Be8-h5 24.Ne6-f4 Bh5-d1+ 25.Kc2-b1 Bd1-g4 26.Nf4-g2+ Ke1-e2 27.Ng2-e3 Bg4-h5 28.Kb1-b2 Bh5-e8 29.Kb2-b1 Be8-d7 30.Kb1-c2 Ne5-f3 31.Kc2-b2 Nf3-h4 32.f5-f6 Nh4-g6 33.Kb2-c2 Ng6-e5 34.Bc1-b2 Bd7-e6 35.Ne3-g2 Ke2-f3
 48/72-	26:19	 24,014,623k	15,206k	-2.24	1.Nc8xb6 c7xb6
 48/85	28:38	 26,150,071k	15,218k	-2.24	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Re6-f6 6.Re3-e1 Qd8xc7 7.Ra7xc7 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b2 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb2-b1 Kf2-e1 21.Kb1-c2 Bd7-e8 22.Bc1-b2 Be8-h5 23.Bb2-c1 Bh5-g4 24.Kc2-b1 Ke1-d1 25.Nd4-c2 Bg4-h5 26.Nc2-e3+ Kd1-e2 27.Ne3-d5 Bh5-e8 28.Nd5-f4+ Ke2-d1 29.Nf4-g2 Be8-d7 30.Ng2-e3+ Kd1-e2 31.Kb1-c2 Ne5-f3 32.f5-f6 Nf3-e5 33.Ne3-g2 Bd7-e8 34.Bc1-b2 Be8-f7 35.Ng2-h4 Ke2-e1 36.Nh4-g2+ Ke1-f2 37.Ng2-e3 Bf7-e6 38.Kc2-d1
 49/69	37:08	 33,582,850k	15,068k	-2.36	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 Rh8-h6 10.Ka1-b1 h5-h4 11.Rc7-c8 Rf6-f8 12.Rg1-h1+ Kh3-g3 13.Rc8xf8 Nd7xf8 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-d7 19.f4-f5 Ng6-e5 20.Kb1-b2 Bd7-e8 21.Kb2-c2 Kf2-e1 22.Nd4-e6 Be8-h5 23.Ne6-f4 Bh5-d1+ 24.Kc2-b1 Bd1-g4 25.Nf4-g2+ Ke1-e2 26.Ng2-e3 Bg4-h5 27.Ne3-g2 Bh5-e8 28.Ng2-f4+ Ke2-d1 29.Nf4-g2 Be8-d7 30.Ng2-e3+ Kd1-e2 31.Kb1-b2 Ne5-f3 32.Kb2-c2 Nf3-h4 33.f5-f6 Bd7-e6 34.Bc1-b2
 50/69	40:13	 36,296,939k	15,038k	-2.36	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 Rh8-h6 10.Ka1-a2 h5-h4 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f1 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Ka2-b2 Kf1-e1 21.Nd4-c2+ Ke1-e2 22.Nc2-e3 Be8-d7 23.Kb2-c2 Ne5-f3 24.f5-f6 Nf3-e5 25.Bc1-b2 Bd7-e6 26.Bb2-a1 Ne5-d7 27.Kc2-c1 Nd7xf6 28.Ne3-c2 Ke2-f2 29.Ba1-b2 Nf6-h5 30.Kc1-d1 Nh5-f4 31.Nc2-e3 Be6-d7 32.Bb2-c1 Nf4-d3 33.Kd1-c2 Kf2-e2 34.Ne3-d5 Nd3-e1+ 35.Kc2-b1
 51/88+	40:39	 36,678,613k	15,033k	-2.19	1.Nc8xb6
 51/88	54:22	 48,586,751k	14,891k	-2.36	1.Nc8xb6 c7xb6 2.Ne1-g2 Bc6xa8 3.Qb8xa8 Re6-g6 4.Qa8-e8 Nf8-e6 5.Qe8-d7 Qg8-e8 6.Qd7-d5 Ne6xf4 7.Ng2xf4 Kg4xf4 8.Re3-e1 Rg6-g3 9.Qd5-d4 Rh8-g8 10.Bb1-c2 Rg3-f3 11.Qd4xb6 Qe8-b8 12.Qb6-d4 d3xc2 13.d2-d3+ Kf4-g4 14.d3xe4 Qb8-h2 15.e4xf5+ Kg4-h3 16.Qd4-e4 Qh2-g3 17.Ka1-b2 Rg8-g4 18.Qe4-e2 Qg3-f2 19.Qe2-e5 Rg4-g1 20.Re1xg1 Qf2xg1 21.Qe5xb5 Qg1-d1 22.f5-f6 Rf3xf6 23.Qb5xc4 Rf6-f1 24.Qc4-e6+ Kh3xh4 25.Qe6-e3 Qd1-f3 26.Qe3-d4+ Kh4-h3 27.b4-b5 Qf3-f7 28.c3-c4 h5-h4 29.b5-b6 Rf1-f3 30.Kb2xc2 Qf7-f5+ 31.Kc2-d2
 52/53-	1:05:50	 58,471,668k	14,802k	-2.47	1.Nc8xb6 c7xb6
 52/91	1:08:33	 60,802,129k	14,780k	-2.50	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb1-c2 Kf2-e1 21.Bc1-b2 Be8-h5 22.Bb2-c1 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2 26.Ne3-d5 Bh5-e8 27.Kb1-c2 Be8-d7 28.Nd5-e3 Ne5-f3 29.Kc2-b2 Nf3-h4 30.f5-f6 Nh4-g6 31.Kb2-c2 Ng6-e5 32.Ne3-g2 Bd7-e8 33.Ng2-f4+ Ke2-e1 34.Nf4-g2+ Ke1-f1 35.Ng2-e3+ Kf1-e2 36.Ne3-d5 Ne5-d7 37.Nd5-f4+ Ke2-f2 38.Kc2-d1 Nd7xf6 39.Nf4-e6 Be8-h5+ 40.Kd1-c2 Nf6-d5 41.Ne6-d4 Bh5-g6 42.Kc2-d1 Bg6-e8 43.Kd1-c2 Nd5-f4 44.Nd4-f5 Be8-g6
 53/93	1:11:00	 62,920,627k	14,769k	-2.50	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb1-c2 Kf2-e1 21.Bc1-b2 Be8-h5 22.Bb2-c1 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2 26.Ne3-d5 Bh5-e8 27.Kb1-c2 Be8-d7 28.Nd5-e3 Ne5-f3 29.Kc2-b2 Nf3-h4 30.f5-f6 Nh4-g6 31.Kb2-c2 Ng6-e5 32.Ne3-g2 Bd7-e8 33.Ng2-f4+ Ke2-e1 34.Nf4-g2+ Ke1-f1 35.Ng2-e3+ Kf1-e2 36.Ne3-d5 Ne5-d7 37.Nd5-f4+ Ke2-f2 38.Kc2-d1 Nd7xf6 39.Nf4-h3+ Kf2-f1 40.Nh3-f4 Be8-h5+ 41.Kd1-c2 Kf1-e1 42.Nf4-g2+ Ke1-f2 43.Ng2-e3 Nf6-d7 44.Kc2-b1 Nd7-e5 45.Kb1-c2
 54/87	1:12:39	 64,341,651k	14,758k	-2.50	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb1-c2 Kf2-e1 21.Bc1-b2 Be8-h5 22.Bb2-c1 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2 26.Ne3-d5 Bh5-e8 27.Kb1-c2 Be8-d7 28.Nd5-e3 Ne5-f3 29.Kc2-b2 Nf3-h4 30.f5-f6 Nh4-g6 31.Kb2-c2 Ng6-e5 32.Ne3-g2 Bd7-e8 33.Ng2-f4+ Ke2-f1 34.Nf4-e6 Kf1-e1 35.Ne6-f4 Be8-f7 36.Nf4-g2+ Ke1-f2 37.Ng2-e3 Kf2-e2 38.Ne3-f5 Ne5-d7 39.Nf5-g3+ Ke2-e1 40.Ng3-f5 Nd7xf6 41.Nf5-e3 Bf7-g6 42.Ne3-g2+ Ke1-f2 43.Ng2-e3 Kf2-e2 44.Bc1-b2
 55/79	1:14:23	 65,844,396k	14,753k	-2.50	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb1-c2 Kf2-e1 21.Bc1-b2 Be8-h5 22.Bb2-c1 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2 26.Ne3-d5 Bh5-e8 27.Kb1-c2 Be8-d7 28.Nd5-e3 Ne5-f3 29.Kc2-b2 Nf3-h4 30.f5-f6 Nh4-g6 31.Kb2-c2 Ng6-e5 32.Ne3-g2 Bd7-e8 33.Ng2-f4+ Ke2-f1 34.Nf4-e6 Kf1-e1 35.Ne6-f4 Be8-f7 36.Nf4-g2+ Ke1-f2 37.Ng2-e3 Ne5-d7 38.Ne3-g4+ Kf2-e2 39.Bc1-b2 Bf7-h5 40.Ng4-e3
 56/94	1:18:11	 69,108,299k	14,730k	-2.50	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb1-c2 Kf2-e1 21.Bc1-b2 Be8-h5 22.Bb2-c1 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2 26.Ne3-d5 Bh5-e8 27.Kb1-c2 Be8-d7 28.Nd5-e3 Ne5-f3 29.Kc2-b2 Nf3-h4 30.f5-f6 Nh4-g6 31.Kb2-c2 Ng6-e5 32.Ne3-g2 Bd7-e8 33.Ng2-f4+ Ke2-f1 34.Nf4-e6 Kf1-e1 35.Ne6-f4 Be8-f7 36.Nf4-g2+ Ke1-e2 37.Ng2-f4+ Ke2-f2 38.Nf4-h3+ Kf2-e1 39.Nh3-f4 Ne5-g4 40.Nf4-g2+ Ke1-f2 41.Ng2-e3 Ng4xf6 42.Bc1-b2 Kf2-e2 43.Ne3-f5 Nf6-g4 44.Bb2-c1 Ke2-e1 45.Nf5-e3 Ng4-f6 46.Ne3-g2+ Ke1-e2 47.Ng2-e3
 57/43+	1:18:41	 69,547,198k	14,731k	-2.32	1.Nc8xb6
 57/85+	1:19:11	 69,984,940k	14,729k	-2.15	1.Nc8xb6
 57/89	1:44:41	 92,035,440k	14,653k	-2.64	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8-c7 Rh6-d6 13.Rg1-g7 Bc6-d5 14.Rg7xd7 Rd6xd7 15.Rc7xd7 Bd5-f7 16.d2-d4 c4xd3/ep 17.Rd7-d6 Kh3-h2 18.Rd6-h6 h4-h3 19.c3-c4 b5xc4 20.Bc1-b2 Rf8-d8 21.Bb2-c3 b6-b5 22.Kb1-c1 d3-d2+ 23.Bc3xd2 Rd8-d3 24.Kc1-c2 c4-c3 25.Bd2-c1 Bf7-b3+ 26.Kc2-b1 Kh2-g3 27.Rh6-h7 Bb3-d1 28.Ne3xf5+ Kg3-f2 29.Bc1-e3+ Kf2-f3 30.Rh7-h4 Bd1-b3 31.Rh4xh3+ Kf3-g4 32.Rh3-g3+ Kg4xf5 33.Rg3-g5+ Kf5-f6 34.Be3-c1 Bb3-d5 35.Kb1-c2 Bd5-c4 36.Rg5-e5 Rd3-h3 37.Re5-g5
 58/93	1:55:40	101,339,825k	14,602k	-2.67	1.Nc8xb6 c7xb6 2.Bb1-c2 d3xc2 3.Ra8-a7 Nf8-d7 4.Qb8-c7 Qg8-d8 5.Ne1xc2 Qd8xc7 6.Ra7xc7 Re6-f6 7.Re3-e1 Kg4xh4 8.Re1-g1 Kh4-h3 9.Nc2-e3 h5-h4 10.Ka1-b1 Rh8-h6 11.Rc7-c8 Rf6-f8 12.Rc8xf8 Nd7xf8 13.Rg1-h1+ Kh3-g3 14.Ne3xf5+ Kg3-g2 15.Rh1xh4 Rh6xh4 16.Nf5xh4+ Kg2-f2 17.Nh4-f5 Nf8-g6 18.Nf5-d4 Bc6-e8 19.f4-f5 Ng6-e5 20.Kb1-c2 Kf2-e1 21.Bc1-b2 Be8-h5 22.Bb2-c1 Bh5-g4 23.Kc2-b1 Ke1-d1 24.Nd4-c2 Bg4-h5 25.Nc2-e3+ Kd1-e2 26.Ne3-d5 Bh5-e8 27.Nd5-f4+ Ke2-d1 28.Nf4-d5 Be8-d7 29.Nd5-e3+ Kd1-e2 30.Kb1-b2 Ne5-f3 31.Kb2-c2 Nf3-h4 32.f5-f6 Bd7-e6 33.Bc1-b2 Nh4-f3 34.Bb2-c1 Nf3-e5 35.Ne3-g2 Be6-f7 36.Ng2-f4+ Ke2-f1 37.Bc1-b2 Ne5-g4 38.Kc2-c1 Ng4xf6 39.Kc1-d1 Bf7-e8 40.Nf4-e6 Be8-h5+ 41.Kd1-c1 Nf6-g4 42.Ne6-d4 Ng4-f2 43.Nd4-c2 Nf2-d3+ 44.Kc1-b1 Kf1-e2 45.Bb2-c1 Bh5-g6 46.Nc2-e3 Nd3-e1 47.Kb1-b2

acase · Post by **acase** » Thu Mar 30, 2023 7:13 pm

Eelco de Groot wrote: ↑Thu Mar 30, 2023 2:22 pm Other moves than 1.Nxb6 are not very promising says Crystal;

[fen]RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - -[/fen]

Engine: Crystal 5 KWK NNUE II (512 MB)
gemaakt door the Stockfish developers (see AUTHORS f

32 153:47 -1.21 1.Pxb6 cxb6 2.Pg2 Te8 3.Dxb6 Lxa8
4.Te1 e3 5.Pxe3+ Txe3 6.Dxe3 Kxh4
7.Tg1 Lg2 8.De5 Pd7 9.De7+ Kh3
10.Dxd7 Dd5 11.De7 Tg8 12.Te1 Le4
13.Te3+ Kg4 14.Dh7 (7.425.854.044) 804

32 153:47 -8.21 1.Pxd3 Lxe3 2.Pe5+ Txe5 3.fxe5 Pg6
4.dxe3 Lxa8 5.Dxa8 Dxc8 6.Dd5 Pxh4
7.e6 Dd8 8.De5 Pg6 9.Dxb5 h4 10.Lxe4 fxe4
11.Dc6 Kf5 12.e7 Dxe7 13.Dxc4 Kg5
14.Df1 (7.425.854.044) 804

32 153:47 -8.39 1.Lxd3 Lxe3 2.Lb1 Pd7 3.Dxc7 Dd8
4.Dxd8 Txd8 5.Ta6 Lxf4 6.Pa7 Pb8
7.Tb6 Lc7 8.Txb5 Lxb5 9.Pxb5 Lg3
10.Pc2 f4 11.La2 Pc6 12.Lxc4 Te7
13.d4 exd3 14.Pbd4 (7.425.854.044) 804

32 153:47 -8.81 1.Pg2 Pd7 2.Pxb6 Pxb8 3.Pxc4 bxc4
4.Ta7 Pd7 5.La2 Pb6 6.Kb2 Tg6 7.Txc7 Db8
8.Tf7 Pd5 9.Te1 Kh3 10.Txf5 Txg2
11.Lxc4 Dxf4 12.Txf4 Pxf4 13.La6 La8
14.c4 (7.425.854.044) 804

32 153:47 -9.15 1.Ta6 Pd7 2.Txb6 Pxb8 3.Txb8 Kxh4
4.Pe7 Txe7 5.Txg8 Txg8 6.Lxd3 cxd3
7.Pxd3 Tg3 8.Pe5 Txe5 9.fxe5 Tg1
10.Te2 f4 11.Th2+ Kg4 12.Kb2 f3
13.d3 exd3 14.Le3 (7.425.854.044) 804

So if the 1.Nxb6 line is to work, you have to show something better for White I suppose, mabybe after

[pgn][Event "Computer chess game"]
[Site "WORKSTATION-PC"]
[Date "2023.03.29"]
[Round "?"]
[White "Stockfish"]
[Black "Stockfish"]
[WhiteElo "3600"]
[BlackElo "2000"]
[Result "*"]
[SetUp "1"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - -"]

1. Nxb6 cxb6 2. Ng2 Re8 3. Qxb6 Bxa8 4. Re1 e3 5. Nxe3+
Rxe3 6. Qxe3 Kxh4 *[/pgn]

Best five moves for Crystal here

[fen]b4nqr/8/8/1p3p1p/pPp2P1k/P1PpQ3/3P4/KBB1R3 w - -[/fen]

Engine: Crystal 5 KWK NNUE II (512 MB)
gemaakt door the Stockfish developers (see AUTHORS f

29 12:54 -1.01 7.Dc5 Le4 8.Dxb5 Th6 9.Dc5 Pd7
10.Dd4 Pf6 11.La2 Dg3 12.Tg1 Df3
13.Lxc4 Pg4 14.Lb5 Kh3 15.c4 Df2
16.Dxf2 Pxf2 17.Lb2 h4 18.c5 Lg2
19.Tc1 Kg3 20.c6 (683.109.481) 882

28 12:54 -1.44 7.Dd4 Lg2 8.Df6+ Kg4 9.Tg1 Kg3
10.Dxf5 h4 11.De5 Pe6 12.De3+ Kh2
13.Td1 Pxf4 14.Dxf4+ Dg3 15.Df7 Tg8
16.Lb2 Tg5 17.Df6 Te5 18.Db6 Kh3
19.Tc1 Df3 20.Dd6 (683.109.481) 882

28 12:54 -2.03 7.Db6 Pd7 8.Dxb5 Df7 9.Tg1 De6
10.Dxa4 Lf3 11.La2 Kh3 12.b5 Tc8
13.Db4 Ld5 14.Tg5 Pf6 15.b6 Tb8
16.a4 Dxb6 17.Txf5 Tb7 18.a5 De6
19.Te5 Txb4 20.Txe6 (683.109.481) 882

28 12:54 -2.34 7.De8 Dg3 8.Te3 Pg6 9.De6 Lf3
10.Dxf5 Tb8 11.Df6+ Kh3 12.De6+ Kg2
13.f5 Pf4 14.Dd7 Pe2 15.Lb2 Tf8
16.Dxb5 Df4 17.Dxa4 h4 18.b5 h3
19.Db4 Dxe3 20.Dxf8 (683.109.481) 882

28 12:54 -2.50 7.Kb2 Le4 8.Tg1 Lg2 9.Dc5 Pd7
10.Dxb5 Dd5 11.Dxa4 Pf6 12.Da6 Dc6
13.Dxc6 Lxc6 14.La2 Ld5 15.Tg5 Tf8
16.a4 Pe4 17.Tg7 Tf7 18.Tg8 Ta7
19.Td8 Le6 20.Ka3 (683.109.481) 882

Hi Eelco,

Sorry I didn't reply earlier as I was asleep at the time you posted, take a look at Jesus's post for a hint. Although I'm sure you already looked at it by now.

Plutie · Post by **Plutie** » Fri Mar 31, 2023 12:30 am

acase wrote: ↑Thu Mar 30, 2023 4:37 amPerhaps your engines will find this one a little more challenging, I worked on it at my job during my lunch.

Give this one a try
White to play and win
[pgn][Event "Computer chess game"]
[Site "WORKSTATION-PC"]
[Date "2023.03.29"]
[Round "?"]
[White "Stockfish"]
[Black "Stockfish"]
[Result "*"]
[BlackElo "2000"]
[Time "22:14:41"]
[WhiteElo "3600"]
[TimeControl "none"]
[SetUp "1"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[Termination "unterminated"]
[PlyCount "0"]
[WhiteType "human"]
[BlackType "human"]

*[/pgn]

after some looking with both SF and leela:

Ajedrecista's idea seems correct, minus a couple options to delay mate.

what seems to be the intended solution:
1. Nxb6 cxb6
2. Qxf8!

if 2... Bxa8, mate in 10 moves - 3. Qxg8+ Rxg8, then Ng2, Ba2, Bb2, and walk king over to f2.

if 2... Qxf8, Rxf8 wins, and it's mate in the same way if 3... Rxf8. (3... Kxf4/Kxh4 is unfortunately possible though, so the mate idea doesn't work out in all cases.)

multipv search after Nxb6 w/ forward/backward analysis:

[pgn][Event "?"]
[Site "?"]
[Date "2023.03.30"]
[Round "?"]
[White "White"]
[Black "Black"]
[Result "1-0"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[SetUp "1"]

1. Nxb6 cxb6 2. Qxf8 {EV: 99.9%, CP: +6.18} Qxf8 {EV: 99.9%, CP: +3.20} (2...
Bxa8 {EV: 100.0%, CP: +320.00} 3. Qxg8+ {EV: 100.0%, CP: +320.00} Rxg8 {EV:
100.0%, CP: +320.00} 4. Ng2 {EV: 100.0%, CP: +320.00} Bd5 {EV: 100.0%, CP:
+320.00} 5. Ba2 {EV: 100.0%, CP: +320.00} Bb7 6. Bb2 {EV: 100.0%, CP: +320.00}
Bd5 {EV: 100.0%, CP: +320.00} 7. Kb1 {EV: 100.0%, CP: +320.00} Bc6 {EV: 100.0%,
CP: +320.00} 8. Kc1 {EV: 100.0%, CP: +320.00} Bd5 {EV: 100.0%, CP: +320.00} 9.
Kd1 {EV: 100.0%, CP: +320.00} Bc6 {EV: 100.0%, CP: +320.00} 10. Ke1 {EV: 100.0%,
CP: +320.00} Bd5 {EV: 100.0%, CP: +320.00} 11. Kf2 {EV: 100.0%, CP: +320.00} Bc6
{EV: 100.0%, CP: +320.00} 12. Rg3# {EV: 100.0%, CP: +320.00}) 3. Rxf8 {EV:
99.9%, CP: +8.19} Rxf8 (3... Kxf4 {EV: 99.9%, CP: +8.13} 4. Rxh8 {EV: 99.9%, CP:
+6.10} Rg6 {EV: 99.9%, CP: +5.94} 5. Ba2 {EV: 99.9%, CP: +5.54} Bd5 {EV: 99.9%,
CP: +6.75} 6. Bb2 Kg4 {EV: 99.9%, CP: +6.04} 7. Ng2 {EV: 99.9%, CP: +6.50} f4
{EV: 99.9%, CP: +6.46} 8. Nxf4 {EV: 99.9%, CP: +6.52} Kxf4 {EV: 99.9%, CP:
+5.82} 9. Rxh5 {EV: 99.9%, CP: +6.44}) 4. Ng2 {EV: 100.0%, CP: +320.00} Rg6 5.
Ba2 {EV: 100.0%, CP: +320.00} Bd5 6. Bb2 {EV: 100.0%, CP: +320.00} Bc6 {EV:
100.0%, CP: +320.00} 7. Kb1 {EV: 100.0%, CP: +320.00} Bd5 {EV: 100.0%, CP:
+320.00} 8. Kc1 {EV: 100.0%, CP: +320.00} Bc6 9. Kd1 {EV: 100.0%, CP: +320.00}
Bd5 10. Ke1 {EV: 100.0%, CP: +320.00} Bc6 11. Kf2 {EV: 100.0%, CP: +320.00} Bd5
{EV: 100.0%, CP: +320.00} 12. Rg3# {EV: 100.0%, CP: +320.00} 1-0
[/pgn]

acase · Post by **acase** » Fri Mar 31, 2023 1:33 am

Plutie wrote: ↑Fri Mar 31, 2023 12:30 am
acase wrote: ↑Thu Mar 30, 2023 4:37 amPerhaps your engines will find this one a little more challenging, I worked on it at my job during my lunch.

Give this one a try
White to play and win
[pgn][Event "Computer chess game"]
[Site "WORKSTATION-PC"]
[Date "2023.03.29"]
[Round "?"]
[White "Stockfish"]
[Black "Stockfish"]
[Result "*"]
[BlackElo "2000"]
[Time "22:14:41"]
[WhiteElo "3600"]
[TimeControl "none"]
[SetUp "1"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[Termination "unterminated"]
[PlyCount "0"]
[WhiteType "human"]
[BlackType "human"]

*[/pgn]
after some looking with both SF and leela:

Ajedrecista's idea seems correct, minus a couple options to delay mate.

what seems to be the intended solution:
1. Nxb6 cxb6
2. Qxf8!

if 2... Bxa8, mate in 10 moves - 3. Qxg8+ Rxg8, then Ng2, Ba2, Bb2, and walk king over to f2.

if 2... Qxf8, Rxf8 wins, and it's mate in the same way if 3... Rxf8. (3... Kxf4/Kxh4 is unfortunately possible though, so the mate idea doesn't work out in all cases.)

multipv search after Nxb6 w/ forward/backward analysis:

[pgn][Event "?"]
[Site "?"]
[Date "2023.03.30"]
[Round "?"]
[White "White"]
[Black "Black"]
[Result "1-0"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[SetUp "1"]

1. Nxb6 cxb6 2. Qxf8 {EV: 99.9%, CP: +6.18} Qxf8 {EV: 99.9%, CP: +3.20} (2...
Bxa8 {EV: 100.0%, CP: +320.00} 3. Qxg8+ {EV: 100.0%, CP: +320.00} Rxg8 {EV:
100.0%, CP: +320.00} 4. Ng2 {EV: 100.0%, CP: +320.00} Bd5 {EV: 100.0%, CP:
+320.00} 5. Ba2 {EV: 100.0%, CP: +320.00} Bb7 6. Bb2 {EV: 100.0%, CP: +320.00}
Bd5 {EV: 100.0%, CP: +320.00} 7. Kb1 {EV: 100.0%, CP: +320.00} Bc6 {EV: 100.0%,
CP: +320.00} 8. Kc1 {EV: 100.0%, CP: +320.00} Bd5 {EV: 100.0%, CP: +320.00} 9.
Kd1 {EV: 100.0%, CP: +320.00} Bc6 {EV: 100.0%, CP: +320.00} 10. Ke1 {EV: 100.0%,
CP: +320.00} Bd5 {EV: 100.0%, CP: +320.00} 11. Kf2 {EV: 100.0%, CP: +320.00} Bc6
{EV: 100.0%, CP: +320.00} 12. Rg3# {EV: 100.0%, CP: +320.00}) 3. Rxf8 {EV:
99.9%, CP: +8.19} Rxf8 (3... Kxf4 {EV: 99.9%, CP: +8.13} 4. Rxh8 {EV: 99.9%, CP:
+6.10} Rg6 {EV: 99.9%, CP: +5.94} 5. Ba2 {EV: 99.9%, CP: +5.54} Bd5 {EV: 99.9%,
CP: +6.75} 6. Bb2 Kg4 {EV: 99.9%, CP: +6.04} 7. Ng2 {EV: 99.9%, CP: +6.50} f4
{EV: 99.9%, CP: +6.46} 8. Nxf4 {EV: 99.9%, CP: +6.52} Kxf4 {EV: 99.9%, CP:
+5.82} 9. Rxh5 {EV: 99.9%, CP: +6.44}) 4. Ng2 {EV: 100.0%, CP: +320.00} Rg6 5.
Ba2 {EV: 100.0%, CP: +320.00} Bd5 6. Bb2 {EV: 100.0%, CP: +320.00} Bc6 {EV:
100.0%, CP: +320.00} 7. Kb1 {EV: 100.0%, CP: +320.00} Bd5 {EV: 100.0%, CP:
+320.00} 8. Kc1 {EV: 100.0%, CP: +320.00} Bc6 9. Kd1 {EV: 100.0%, CP: +320.00}
Bd5 10. Ke1 {EV: 100.0%, CP: +320.00} Bc6 11. Kf2 {EV: 100.0%, CP: +320.00} Bd5
{EV: 100.0%, CP: +320.00} 12. Rg3# {EV: 100.0%, CP: +320.00} 1-0
[/pgn]

That is correct, well done. Here is the PGN:

[pgn][Event "Computer chess game"]
[Site "WORKSTATION-PC"]
[Date "2023.03.30"]
[Round "?"]
[White "Workstation"]
[Black "Workstation"]
[Result "1-0"]
[BlackElo "0"]
[Time "09:48:15"]
[WhiteElo "0"]
[TimeControl "0"]
[SetUp "1"]
[FEN "RQN2nqr/2p5/1bb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - - 0 1"]
[Termination "normal"]
[PlyCount "7"]
[WhiteType "program"]
[BlackType "program"]

1. Nxb6! {Although this move is forced it serves 4 purposes, the first is
to remove the threat to the white Rook on e3, the second is to open up the
8th rank for the white Queen, the third is to get the black pawn off of the
c-file so it cannot get to the c5 square and possibly penetrate white's position, and the fourth is to give the white queen access to the 2 other
black pieces that can penetrate the white pawn fortress namely the black
Knight on f8 and the black Queen on g8.} cxb6 2. Qxf8!! {This move removes
one of the pieces that can penetrate white's position and forces the
exchane of Queens which incidentally removes the other black piece that
could possibly penetrate white's position.} Qxf8 (2. .. Bxa8? {This leads
to a forced mate beginning with 3.Qxg8} 3. Qxg8+ {+M10/26 80} Rxg8 4. Ng2
Bc6 5. Bb2 Rd6 6. Ba2 Re6 7. Kb1 Reg6 8. Kc1 Bd7 9. Kd1 Rc6 10. Ke1 Rcg6
11. Kf2 Re8 12. Rg3#) 3. Rxf8 Kxf4 4. Rxh8 {And it is all over now, the
overwhelming white material advantage will carry him to an easy victory.} 1-0 *[/pgn]

There is the threat of that mate that I borrowed from that mate in 5 problem as Jesus pointed out, but you must find a way to eliminate the black pieces or move them to a square where they cannot penetrate white's pawn structure, namely the Bishop on b6, the pawn on c7, the Knight on f8 and the Queen on g8, this is an idea that I borrowed from this (also hilarious) study by GM Miguel Illescas:

[pgn][Event "debute Timman-65 JT"]
[Site ""]
[Date "2017"]
[Round ""]
[White "Illescas=M"]
[Black "(=0433.76d2h5)"]
[Result "1/2-1/2"]
[WhiteElo "2602"]
[SetUp "1"]
[FEN "1r6/1n1R1b2/8/1p1p3k/pPpPp1p1/2P1P3/P2K1PP1/8 w - - 0 1"]
[PlyCount "27"]
[EventDate "2017"]
[SourceDate "2006.05.01"]

{A problem computers cannot solve... yet} 1. Rxb7 $1 (1. Rxf7 $2 g3 $1 $19) 1... Rf8 $1 (1... Rxb7 2. g3 $1 Kg5 3. Ke2 Rb6 4. Kf1 Rh6 5. Kg2 $11 {draw as in the main line}) 2. g3 $1 (2. Ke2 $2 g3 $1 $19) 2... Kg6 $1 3. Rb6+ $1 (3. Rxb5 $2 Be8 $19) (3. Ke2 $2 Rh8 $19) 3... Kg7 4. Rh6 $1 Kxh6 5. Ke2 ({or} 5. Ke1) 5... Kg5 6. Kf1 $1 Rh8 7. Kg2 ({or} 7. Kg1) 7... a3 8. Kg1 $1 Ra8 9. Kg2 ( {or} 9. Kf1) 9... Ra4 10. Kf1 $1 Be6 11. Ke1 ({or} 11. Ke2) 11... Ra8 12. Kf1 $1 Bf7 13. Kg2 ({or} 13. Kg1) 13... Ra4 14. Kf1 1/2-1/2[/pgn]

I figured why not make a position based on that idea that you can win.

Here is the mate in 5 position and the reason I find it hilarious is that the vast majority of engines don't see the mate in 5 and would rather focus on the FREE ROOK!!!!!, although that certainly wins it's like flying an airplane from New York city to Miami Florida but flying all the way to Los Angeles first and then getting on another plane to fly to final destination of Miami Florida, the other thing I found funny about it was I was reading a translated in Computer Schach und Spiel online thread from 2021 where one of the comments said "I didn't expect top engines to be so stupid about the position", and hes was right

. of course the mate finding engines will find it quickly like the Huntsman and Crystal, but most of the other engines opt for the Rook.

here is the PGN to the mate in 5
[pgn][Event "Mate in 5 problem by Friedrich Köhnlein"]
[Site "WORKSTATION-PC"]
[Date "1904"]
[Round "?"]
[White "Workstation"]
[Black "Workstation"]
[Result "1-0"]
[BlackElo "2400"]
[WhiteElo "2400"]
[TimeControl "0"]
[SetUp "1"]
[FEN "8/2Nb4/pp6/4rp1p/1Pp1pPkP/PpPpR3/1B1P2N1/1K6 w - - 0 1"]
[Termination "normal"]
[PlyCount "9"]
[WhiteType "human"]
[BlackType "human"]

1. Kc1 a5 2. Kd1 axb4 3. Ke1 bxc3 4. Kf2 cxb2 5. Rg3# 1-0[/pgn]

and here is the forum thread I was talking about:
https://forum.computerschach.de/cgi-bin ... ?tid=12512

I should mention that Crystal 5 KWK WILL solve this if you let it think long enough, and Houdini 5 tactical seems to solve it also.

Jouni · Post by **Jouni** » Fri Mar 31, 2023 8:48 am

Analysis by Stockfish dev-20230319-02e46970

1.fxe5 Bc6 2.Ne6 f4 3.Nexf4 Kf5 4.e6 Kf6 5.Rg3 b5 6.Rg6+ Kf5 7.Rg5+ Kf6 8.Ne3 Ke7 9.Rg6 Be8 10.Rg8 Bc6 11.Rc8 Kd6 12.e7 Bd7 13.e8Q Bxe8 14.Rxe8 Kc6 15.Rxe4 Kc7 16.Ned5+ Kb7 17.Re6 Ka7 18.Rb6 Ka8 19.Rxa6+ Kb8 20.Re6 Kb7
+- (#34) Depth: 39/48 00:05:54 3783mN, tb=41297

peter · Post by **peter** » Fri Mar 31, 2023 2:00 pm

Jouni wrote: ↑Fri Mar 31, 2023 8:48 am Analysis by Stockfish dev-20230319-02e46970

1.fxe5 Bc6 2.Ne6 f4 3.Nexf4 Kf5 4.e6 Kf6 5.Rg3 b5 6.Rg6+ Kf5 7.Rg5+ Kf6 8.Ne3 Ke7 9.Rg6 Be8 10.Rg8 Bc6 11.Rc8 Kd6 12.e7 Bd7 13.e8Q Bxe8 14.Rxe8 Kc6 15.Rxe4 Kc7 16.Ned5+ Kb7 17.Re6 Ka7 18.Rb6 Ka8 19.Rxa6+ Kb8 20.Re6 Kb7
+- (#34) Depth: 39/48 00:05:54 3783mN, tb=41297

Nice anti- engine- puzzle acase has made out of the Illescas- study, hasn't he?

Here's SF dev. with MultiPV=12 at position after 2 plies before the crucial 2.Qxf8!:

[fen]RQ3nqr/8/1pb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - -[/fen]

Engine: Stockfish dev-20230305-cdec775a0 (32768 MB)
von the Stockfish developers (see AUTHORS f

Code: Select all

23/37	 0:34 	-2.80 	2.Ta7 Sd7 (1.022.787.644) 29265
 22/47	 0:34 	-2.77 	2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Teg6 5.Sg2 Sf6 6.a4 Sd5 7.axb5 Lxb5 8.Th7 Sxf4 9.Sxf4 Kxf4 10.Te1 Tg1 11.Txg1 Txg1 12.Kb2 Tg2 13.Ka3 Kg4 14.Te7 Te2 15.Te6 (1.022.787.644) 29265
 22/49	 0:34 	-2.91 	2.Dc8 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 5.Dxb5 Tg6 6.De5 Dg7 7.Db5 Dc7 8.Dxa4 Kxh4 9.La2 Tc8 10.Tf3 Tg1 11.Dd1 Tcg8 12.Lxc4 T8g3 13.Txg3 Kxg3 (1.022.787.644) 29265
 23/43	 0:35 	-0.36 	2.Sg2 Lxa8 3.Dxa8 Tg6 4.Db8 Se6 5.De5 Db8 6.Dxb5 Sxf4 7.Sxf4 Dxf4 8.Dxc4 Thg8 9.Lxd3 Kxh4 10.Kb2 Tg3 11.Lc2 Tg1 12.Lxa4 T8g3 13.Lc2 Txe3 14.dxe3 Df2 15.Dd5 (1.026.111.626) 29262
 23/45	 0:35 	-0.59 	2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dd8 5.Sxc2 Dxc7 6.Txc7 Th7 7.Te1 Sf6 8.Se3+ Kxh4 9.Th1+ Kg3 10.Sxf5+ Kg4 11.Se3+ Kxf4 12.Tf1+ Ke5 13.Txh7 Sxh7 14.Tf5+ Kd6 15.Txh5 (1.026.111.626) 29262
 23/45	 0:35 	-1.63 	2.Dxb6 Lxa8 3.Dc5 Sd7 4.Dxb5 Lc6 5.Dxc4 Td6 6.Da6 Kxh4 7.Da5 Kg4 8.Da6 Da8 9.Dc4 h4 10.Sxd3 Txd3 11.Lxd3 exd3 12.Dxd3 Sf6 13.c4 Lf3 14.Df1 h3 15.Dg1+ (1.026.111.626) 29262
 23/37	 0:35 	-1.72 	2.Ta6 Sd7 3.Dc7 Dd8 4.Ta7 Dxc7 5.Txc7 Tg8 6.Sxd3 cxd3 7.Lxd3 Kxh4 8.Te1 Tg3 9.Le2 Sf6 10.Tf7 Td6 11.c4 bxc4 12.Lb2 Sg4 13.Th1+ Th3 14.Txh3+ Kxh3 (1.026.111.626) 29262
 23/45	 0:35 	-2.05 	2.La2 Lxa8 3.Dxa8 Td6 4.Da6 Sg6 5.Dxb5 De8 6.Dxc4 Dc6 7.Df7 Dd7 8.Dxd7 Txd7 9.Lc4 Sxf4 10.Lb5 Tf7 11.c4 Kxh4 12.c5 bxc5 13.Lb2 Tg8 14.Lc4 Tff8 15.Le5 (1.026.111.626) 29262
 23/39	 0:35 	-2.07 	2.Dd8 Lxa8 3.Lc2 dxc2 4.Te2 Lc6 5.Dd4 e3 6.dxe3 Kh3 7.e4 Dg3 8.Te3 Tg8 9.e5 Le4 10.Txg3+ Txg3 11.Kb2 Teg6 12.Le3 Se6 13.Dd2 Tg8 14.De2 Td8 15.Df1+ (1.026.111.626) 29262
 23/47	 0:35 	-2.07 	2.Te2 dxe2 3.Dxb6 e3 4.Tc8 Lf3 5.Dc5 Te4 6.Lxe4 fxe4 7.Dxe3 Kxh4 8.d4 Dg3 9.Ld2 Sg6 10.Tc5 Sxf4 11.Dxf4+ Dxf4 12.Lxf4 Tg8 13.Kb2 Tg1 14.Le3 Tf1 15.Ld2 (1.026.111.626) 29262
 23/55	 0:35 	-2.15 	2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 5.Dxb5 Dc8 6.Dxa4 Kxh4 7.Dd1 Tg8 8.Sxd3 Sxd3 9.Lxd3 cxd3 10.Df1 Kg5 11.Th3 De8 12.Tg3+ Kf6 13.c4+ Ke7 14.Txg8 Dxg8 15.Dxf5 (1.026.111.626) 29262
 23/37	 0:35 	-2.57 	2.Ta7 Sd7 3.Dxg8+ Txg8 4.Sg2 Teg6 5.Tc7 Sf6 6.Txc6 Sd5 7.Txg6+ Txg6 8.Te1 Kf3 9.Se3 Sxe3 10.dxe3 Tg4 11.Th1 Kg2 12.Td1 Txh4 13.Lc2 Th3 14.Td2+ Kg3 15.Ld1 (1.026.111.626) 29262
 23/37	 0:35 	-2.72 	2.Sc2 Lxa8 3.Dxa8 Td6 4.Txe4 dxc2 5.Te5 cxb1D+ 6.Kxb1 Td3 7.Dh1 Kxf4 8.Txb5 Dg4 9.Dh2+ Dg3 10.De2 Sg6 11.De6 Sxh4 12.De5+ Kf3 13.Dxh8 Dg6 14.Ka1 Kf2 15.Dc8 (1.026.111.626) 29262
 22/47	 0:35 	-2.77 	2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Teg6 5.Sg2 Sf6 6.a4 Sd5 7.axb5 Lxb5 8.Th7 Sxf4 9.Sxf4 Kxf4 10.Te1 Tg1 11.Txg1 Txg1 12.Kb2 Tg2 13.Ka3 Kg4 14.Te7 Te2 15.Te6 (1.026.111.626) 29262
 22/49	 0:35 	-2.91 	2.Dc8 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 5.Dxb5 Tg6 6.De5 Dg7 7.Db5 Dc7 8.Dxa4 Kxh4 9.La2 Tc8 10.Tf3 Tg1 11.Dd1 Tcg8 12.Lxc4 T8g3 13.Txg3 Kxg3 (1.026.111.626) 29262
...
 25/48	 1:13 	-0.58 	2.Sg2 Lxa8 3.Dxa8 Tg6 4.De8 Se6 5.Dd7 De8 6.Dd5 Sc7 7.Dd4 Dd8 8.Lc2 dxc2 9.Tg3+ Kxg3 10.Dg1 Dd3 11.Se3+ Kf3 12.Dh1+ Kxf4 13.Dh2+ Tg3 14.Df2+ Ke5 15.Dxg3+ (2.119.079.464) 28994
 25/38	 1:13 	-0.65 	2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dd8 5.Sxc2 Dxc7 6.Txc7 Th7 7.Te1 Sf6 8.Se3+ Kxh4 9.Th1+ Kg3 10.Sxf5+ Kg4 11.Se3+ Kxf4 12.Tf1+ Ke5 13.Tf5+ Kd6 14.Txh7 Sxh7 15.Txh5 (2.119.079.464) 28994
 25/40	 1:13 	-1.91 	2.Dxb6 Lxa8 3.Dxb5 Sg6 4.Sg2 De8 5.Dxc4 Dc6 6.Lxd3 exd3 7.Dxe6 Dxe6 8.Txe6 Sxh4 9.Se3+ Kxf4 10.c4 Sf3 11.Sg2+ Kg5 12.Lb2 Tg8 13.Lf6+ Kg4 14.Se3+ Kf4 15.Kb2 (2.119.079.464) 28994
 25/48	 1:13 	-2.15 	2.Te2 dxe2 3.Dxb6 e3 4.Tc8 Lf3 5.Dd4 Te4 6.Lxe4 fxe4 7.Dxe3 Kxh4 8.d4 Dg3 9.Ld2 Sg6 10.Tc7 Tf8 11.Tg7 Dxf4 12.Txg6 Dxe3 13.Lxe3 Lg4 14.Kb2 Kg3 15.Ld2 (2.119.079.464) 28994
 25/49	 1:13 	-2.17 	2.Ta6 Sd7 3.Da7 Kxh4 4.Txb6 Sxb6 5.Dxb6 Dg4 6.Dc7 Tg8 7.Df7 Dg6 8.Da7 Dg7 9.Dc5 Dg4 10.Dd4 Dg1 11.Kb2 Kg4 12.Lc2 dxc2 13.Sxc2 h4 14.Da7 Tgg6 15.Dh7 (2.119.079.464) 28994
 25/54	 1:13 	-2.24 	2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 5.Dxb5 Dc8 6.Dxa4 Kxh4 7.La2 Tg8 8.Db5 Tg5 9.Lxc4 Dc6 10.Da6 Tg1 11.Ka2 Teg6 12.Lb5 De6+ 13.c4 T6g3 14.Ld4 Txe3 15.Lxe3 (2.119.079.464) 28994
 25/46	 1:13 	-2.30 	2.La2 Lxa8 3.Dxa8 Td6 4.Da6 Sg6 5.Dxb5 De8 6.Dxc4 Dc6 7.Df7 Dd7 8.Dxd7 Txd7 9.Lc4 Sxf4 10.Lb5 Tf7 11.c4 Kxh4 12.c5 bxc5 13.Lb2 Tg8 14.bxc5 Sd5 15.Sf3+ (2.119.079.464) 28994
 25/41	 1:13 	-2.34 	2.Dd8 Lxa8 3.Dd4 Sh7 4.Sg2 Sf6 5.Te1 e3 6.Sxe3+ Txe3 7.Dxe3 Kxh4 8.Dxb6 Sg4 9.Dxb5 Dd5 10.Da6 Lc6 11.La2 Ta8 12.Dxc4 Dxc4 13.Lxc4 Le4 14.Lf7 Tf8 15.Lg6 (2.119.079.464) 28994
 25/43	 1:13 	-2.81 	2.Ta7 Sd7 3.Dxg8+ Txg8 4.Lxd3 cxd3 5.Sxd3 Kxh4 6.Sf2 Tg3 7.Te1 e3 8.Sd1 exd2 9.Lxd2 Td6 10.Le3 Txd1+ 11.Txd1 Txe3 12.Td6 Sb8 13.Td8 Sd7 14.Tc7 Txc3 15.Kb2 (2.119.079.464) 28994
 
 25/50	 1:13 	-2.86 	2.Dxf8 Dxf8 3.Txf8 Txf8 4.Sg2 Ld7 5.Lb2 Tg6 6.Ka2 Lc8 7.Ka1 Le6 8.Lc1 Ld5 9.Ka2 Te8 10.Lb2 Tgg8 11.Ka1 Lc6 12.Lc1 La8 13.Ka2 Ld5 14.Ka1 Tg6 15.Lb2 (2.119.079.464) 28994
 
 25/48	 1:13 	-3.07 	2.Sc2 Lxa8 3.Dd8 Sh7 4.Dd4 dxc2 5.Lxc2 Sf6 6.Te1 e3 7.Tg1+ Kf3 8.Txg8 Txg8 9.dxe3 Le4 10.Dd1+ Kf2 11.Dd2+ Kg3 12.Lxe4 Txe4 13.Dd6 Tg6 14.Ka2 Kh3 15.Df8 (2.119.079.464) 28994
 25/53	 1:13 	-3.17 	2.Kb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 5.Dxb5 Tg6 6.Dxa4 Dd5 7.Da7 Kxh4 8.Dc7 Kg4 9.Lc2 dxc2 10.d3 h4 11.Txe4 fxe4 12.Dxf4+ Kh5 13.dxc4 De6 14.Sxc2 Tg2 15.Kb1 (2.119.079.464) 28994
...

33/63  9:23   -1.49    2.Sg2 Lxa8 3.Dxa8 Tg6 4.Da6 Se6 
                       5.Te1 Kh3 6.Dxb5 Txg2 7.Dxf5+ Dg4 
                       8.Dxe4 Sxf4 9.Dxc4 Tf8 10.Dd4 Kh2 
                       11.Lxd3 Sxd3 12.Dxd3 Tf5 13.c4 Tf3 
                       14.Dd5 Dg3 15.Td1 (15.775.523.852) 27991 

33/60  9:23   -1.55    2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Db8 
                       5.Sxc2 Dxc7 6.Txc7 Tf6 7.Te1 Kxh4 
                       8.Tg1 Thh6 9.Tc8 Thg6 10.Th1+ Kg4 
                       11.Th8 e3 12.T1xh5 Kxf4 13.dxe3+ Ke4 
                       14.Td8 Tf8 15.Txf8 (15.775.523.852) 27991 

33/61  9:23   -2.18    2.Dxb6 Lxa8 3.Dxb5 Sg6 4.Sg2 De8 
                       5.Da5 Dd8 6.Dxa4 Sxh4 7.Sxh4 Dxh4 
                       8.Dd1+ Kxf4 9.Dg1 Td6 10.Te1 Tc8 
                       11.Tf1+ Ke5 12.a4 f4 13.a5 Td7 14.a6 Dg4 
                       15.Dh2 (15.775.523.852) 27991 

33/57  9:23   -2.57    2.Ta6 Sd7 3.Dc7 Kxh4 4.Txb6 Sxb6 
                       5.Dxb6 Dg4 6.Dd4 Tg8 7.Kb2 Dg7 8.Dc5 Df8 
                       9.Sg2+ Kg4 10.Da7 h4 11.Te1 Kh5 
                       12.Se3 Tg7 13.Dd4 Tg3 14.Th1 h3 
                       15.La2 (15.775.523.852) 27991 
                       
Still at nr.5 in depth 33 after about 10 minutes in MultiPV=12 without winning moves nor evals:
33/34  9:23   -2.64    2.Dxf8[/u] Dxf8 3.Txf8 Txf8 4.Sg2 Th8 
                       5.Ka2 The8 6.Ka1 Ld7 7.Ka2 Tg8 8.Lb2 Te7 
                       9.Lc1 Le6 10.Ka1 Lc8 11.Ka2 Lb7 
                       12.Lb2 Ld5 13.Lc1 Tg6 14.Ka1 Lb7 
                       15.Lb2 (15.775.523.852) 27991 

33/34  9:23   -2.64    2.Ta7 Sd7 3.Dxg8+ Txg8 4.Sg2 Teg6 
                       5.Txd7 Lxd7 6.Kb2 Te8 7.Ka1 Th6 
                       8.Ka2 Th7 9.Ka1 The7 10.Ka2 Tg8 
                       11.Kb2 Tg6 12.Ka2 Le6 13.Ka1 Ld5 
                       14.Ka2 Tg8 15.Lb2 (15.775.523.852) 27991 

33/55  9:23   -3.02    2.La2 Lxa8 3.Dxa8 Td6 4.Da6 Sg6 
                       5.Dxb5 De8 6.Dxc4 Dc6 7.Df7 Dd7 
                       8.Dxd7 Txd7 9.Lc4 Sxf4 10.Lb5 Tf7 
                       11.Lb2 Kxh4 12.c4 Tg8 13.Le5 Se2 
                       14.Lh2 Sg3 15.Sxd3 (15.775.523.852) 27991 

33/67  9:23   -3.09    2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Se5 
                       5.fxe5 f4 6.Sg2 f3 7.Se1 Tee8 8.Tc7 La8 
                       9.Lc2 dxc2 10.Sxc2 f2 11.Te2 f1D 
                       12.Se3+ Kf3 13.Sxf1 Kxe2 14.Se3 Txe5 
                       15.Kb2 (15.775.523.852) 27991 

33/60  9:23   -3.18    2.Dd8 Lxa8 3.Sg2 Sh7 4.Dd4 Sf6 5.Te1 e3 
                       6.Sxe3+ Txe3 7.Dxe3 Kxh4 8.Dxb6 Sg4 
                       9.Dxb5 Dd5 10.Dxa4 Df3 11.Da7 Df2 
                       12.Dxf2+ Sxf2 13.Tg1 Kh3 14.La2 Kh2 
                       15.Tg5 (15.775.523.852) 27991 

32/62  9:23   -3.33    2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Kxh4 7.La2 Tg8 
                       8.Db5 Tc6 9.a4 Tg4 10.a5 bxa5 11.De5 De6 
                       12.Dxa5 Ta6 13.Dd8+ Df6 14.Dc7 Sd5 
                       15.Dh2+ (15.775.523.852) 27991 

32/55  9:23   -3.82    2.Dc8 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Lb2 Dd5 7.Dxa4 Kxh4 
                       8.Dd1 Tg3 9.Lxd3 Txe3 10.dxe3 Sxd3 
                       11.Sg2+ Kg5 12.Sf4 Df7 13.a4 Kh6 
                       14.Df1 Tg8 15.b5 (15.775.523.852) 27991 

32/50  9:23   -3.84    2.Kb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Dxa4 Dd5 7.Da7 Kxh4 
                       8.Dc7 Kg4 9.Lc2 dxc2 10.d3 h4 
                       11.Txe4 fxe4 12.Dxf4+ Kh5 13.dxe4 De6 
                       14.e5 Tg4 15.Dd2 (15.775.523.852) 27991

Yet up to 30 minutes (depth 37) output- line of 2.Qxf8 stays about like the one above, so I broke off MultiPV- pondering then

RQ3nqr/8/1pb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - -

Engine: Stockfish dev-20230305-cdec775a0 (32768 MB)
von the Stockfish developers (see AUTHORS f

Code: Select all

37/63  29:01  -1.42    2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dd8 
                       5.Sxc2 Dxc7 6.Txc7 Tf6 7.Te1 Kxh4 
                       8.Tg1 Thh6 9.Se3 Kh3 10.Kb2 h4 
                       11.Tc8 Tf8 12.Th1+ Kg3 13.Txf8 Sxf8 
                       14.Sxf5+ Kg2 15.Txh4 (47.009.440.297) 26986 

37/78  29:01  -1.64    2.Sg2 Lxa8 3.Dxa8 Tg6 4.Da7 Se6 
                       5.Dd7 Dc8 6.Dd5 Td8 7.De5 Te8 8.Dd5 Sc7 
                       9.Dd4 Dd8 10.Lc2 dxc2 11.Tg3+ Kxg3 
                       12.Dg1 Kf3 13.Df1+ Kg4 14.Dg1 Dd3 
                       15.Se3+ (47.009.440.297) 26986 

37/67  29:01  -2.63    2.Ta7 Sd7 3.Dxg8+ Txg8 4.Sg2 Teg6 
                       5.Txd7 Lxd7 6.Lb2 Th6 7.Lc1 Th7 
                       8.Kb2 Le6 9.Ka1 Tf8 10.Lb2 Tc8 
                       11.Lc1 Tg8 12.Kb2 Ld5 13.Ka1 Te7 
                       14.Lb2 Le6 15.Lc1 (47.009.440.297) 26986 

37/68  29:01  -2.67    2.Dxb6 Lxa8 3.Dxb5 Sg6 4.Sg2 De8 
                       5.Da5 Dd8 6.Da7 De7 7.Dxa4 Sxh4 
                       8.Sxh4 Dxh4 9.Dd1+ Kxf4 10.Dg1 Td6 
                       11.Te1 Tc8 12.Tf1+ Ke5 13.a4 f4 
                       14.a5 Td7 15.La2 (47.009.440.297) 26986 

37/44  29:01  -2.67    2.Dxf8 Dxf8 3.Txf8 Txf8 4.Sg2 Tff6 
                       5.Ka2 Ld5 6.Ka1 Tg6 7.Kb2 Te7 8.Ka1 Tg8 
                       9.Lb2 Lb7 10.Lc1 Th7 11.Ka2 Lc8 
                       12.Ka1 Le6 13.Ka2 Ld7 14.Ka1 Lc8 
                       15.Ka2 (47.009.440.297) 26986 

37/80  29:01  -3.13    2.La2 Lxa8 3.Dxa8 Td6 4.Da6 Sg6 
                       5.Dxb5 De8 6.Lxc4 Sxf4 7.Lb2 Dxb5 
                       8.Lxb5 Sd5 9.Sg2 Tf8 10.Te1 Kf3 
                       11.c4 Sc7 12.Lxa4 Kxg2 13.Le5 Tg6 
                       14.Ld4 Te6 15.c5 (47.009.440.297) 26986 

37/70  29:01  -3.13    2.Ta6 Sd7 3.Dc7 Kxh4 4.Txb6 Sxb6 
                       5.Dxb6 Dg4 6.Dc5 Tg8 7.Dd4 Dg1 8.Kb2 Dg7 
                       9.Db6 Dh6 10.Dd4 Tg1 11.Te2 e3 
                       12.Lxd3 cxd3 13.Sxd3 Lf3 14.Txe3 Txe3 
                       15.Dxe3 (47.009.440.297) 26986 

37/72  29:01  -3.35    2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Se5 
                       5.fxe5 f4 6.Sg2 f3 7.Se1 Tee8 8.Tc7 La8 
                       9.Lc2 dxc2 10.Sxc2 f2 11.Te2 f1D 
                       12.Se3+ Kf3 13.Sxf1 Kxe2 14.Se3 Txe5 
                       15.Kb2 (47.009.440.297) 26986 

37/77  29:01  -3.62    2.Dd8 Lxa8 3.Sg2 Sh7 4.Dd4 Sf6 5.Te1 e3 
                       6.Sxe3+ Txe3 7.Dxe3 Kxh4 8.Dxb6 Sg4 
                       9.Dxb5 Dd5 10.Da6 Lc6 11.La2 Ta8 
                       12.Dxc4 Dxc4 13.Lxc4 Le4 14.Lf7 Tf8 
                       15.Lg6 (47.009.440.297) 26986 

37/68  29:01  -3.64    2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Tg8 7.Dd1+ Kxh4 
                       8.Sxd3 Sxd3 9.Lxd3 cxd3 10.De1+ Kg5 
                       11.Tg3+ Kh6 12.De3+ Kh7 13.Th3 Th6 
                       14.Dd4 h4 15.c4 (47.009.440.297) 26986 

37/61  29:01  -3.95    2.Dc8 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Dxa4 Kxh4 7.Dd7 Dd5 
                       8.Dc7 Kg4 9.Lc2 dxc2 10.d4 h4 
                       11.Sxc2 Dc6 12.De5 Df6 13.Dc7 Sd3 
                       14.Ld2 Kh5 15.Te2 (47.009.440.297) 26986 

37/66  29:01  -4.13    2.Da7 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Dxa4 Kxh4 7.Dd7 Dd5 
                       8.Dc7 Kg4 9.Sc2 Dc6 10.Df7 dxc2 
                       11.Lxc2 Sd3 12.Lxd3 cxd3 13.Te1 De6 
                       14.Dc7 h4 15.Tf1 (47.009.440.297) 26986 

38/75  29:47  -1.76    2.Sg2 Lxa8 3.Dxa8 Tg6 4.Db7 Se6 
                       5.Dd7 Dc8 6.Dd5 Td8 7.De5 Te8 8.Dd5 Sc7 
                       9.Dd4 Dd8 10.Lc2 dxc2 11.Tg3+ Kxg3 
                       12.Dg1 Kh3 13.Dh1+ Kg4 14.Dg1 Dd3 
                       15.Se3+ (48.200.114.515) 26963

Giving in solution makes engine see the win rather quickly.
Here after 2.Qf8! and restart of GUI, SF this time single primary with same 30 threads of 16x3.5GHz CPU and 32G hash, Syzygy ProbeLimit=0:

[fen]R4Qqr/8/1pb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 b - -[/fen]

Engine: Stockfish dev-20230305-cdec775a0 (32768 MB)
von the Stockfish developers (see AUTHORS f

Code: Select all

1/01   0:00   -1.88    2...Dxf8 3.Txf8 Txf8 (1.156) 578 

...

48/47  0:04   -2.30    2...Dxf8 3.Txf8 Txf8 4.Sg2 Tfe8 
                       5.Kb2 Tg6 6.Ka2 Teg8 7.Ka1 Ld7 8.Ka2 Te6 
                       9.Ka1 Tge8 10.Lb2 T6e7 11.Ka2 Th7 
                       12.Ka1 Lc8 13.Ka2 Tg8 14.Lc1 Te7 
                       15.Ka1 Tee8 (136.366.868) 30109 

49/50  0:05   -2.45++  2...Dxf8 (169.378.192) 29673 

...

49/56  0:16   -1.03--  2...Dxf8 3.Txf8 (552.698.090) 33725 

49/56  0:21   -0.54--  2...Dxf8 3.Txf8 (762.259.406) 34684 

49/56  0:29   +0.06--  2...Dxf8 3.Txf8 (1.058.069.633) 36189 
...
49/56  2:36   +4.54--  2...Dxf8 3.Txf8 (7.867.417.262) 50359

This time solving of fail high took me too long for edit- time, after 5' still two plies only, eval>6.

Yet ShashChess 30.0 worked quickly enough started from empty hash in MultiPV=12 to get solution up within edit- time:

[fen]RQ3nqr/8/1pb1r3/1p3p1p/pPp1pPkP/P1PpR3/3P4/KBB1N3 w - -[/fen]

Engine: ShashChess 300 (32768 MB)
von K. Kiniama, A. Manzo and Stockfish deve

Code: Select all

20/31  0:12   -1.05    2.Dd8 Lxa8 3.Lc2 dxc2 4.Te2 Lc6 
                       5.Tg2+ Kh3 6.Txg8 Txg8 7.Sxc2 e3 
                       8.Sxe3 Lf3 9.Kb2 Txe3 10.dxe3 Le4 
                       11.Dxb6 Tg2+ 12.Ka1 Tg1 13.Kb2 Sg6 
                       14.Dxb5 Sxh4 15.De8 (306.650.094) 24009 

20/36  0:12   -1.14    2.Te2 dxe2 3.Dxb6 e3 4.Tc8 Lf3 
                       5.Dxb5 Df7 6.Dxc4 Sg6 7.Tc7 Df6 
                       8.Ld3 Tc6 9.Txc6 Dxc6 10.Dd4 Te8 
                       11.b5 Db7 12.dxe3 Sxh4 13.e4 fxe4 
                       14.Dg1+ Kh3 15.Lxe2 (306.650.094) 24009 

20/39  0:12   -1.53    2.La2 Lxa8 3.Dxa8 Sg6 4.Dd5 Dc8 
                       5.Dxb5 Dc6 6.Dxc4 Dxc4 7.Lxc4 Tee8 
                       8.Lb5 Sxf4 9.c4 Kxh4 10.Lb2 Kg4 
                       11.Lxh8 Txh8 12.Ld7 Th7 13.Lxa4 h4 
                       14.Ld1+ Kg5 15.Lf3 (306.650.094) 24009 

20/41  0:12   -1.53    2.Ta7 Sd7 3.Dc7 Kxh4 4.Lc2 Dg1 5.Kb1 Tg8 
                       6.Ld1 Teg6 7.Lc2 Df2 8.Ld1 Df1 9.Lc2 Tg3 
                       10.Txg3 Txg3 11.Dxc6 dxc2+ 12.Kxc2 Dxe1 
                       13.Txd7 Kh3 14.Th7 h4 15.Dxb5 (306.650.094) 24009 

19/42  0:12   -1.70    2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Kxh4 
                       5.Sxd3 cxd3 6.La2 Tge8 7.Lxe6 Txe6 
                       8.a4 bxa4 9.c4 Sf6 10.b5 Sg4 11.Te1 Le8 
                       12.Th1+ Kg3 13.La3 e3 14.dxe3 Sxe3 (306.650.094) 24009 

19/30  0:12   -1.92    2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Tg8 7.Dd1+ Kxh4 
                       8.Sxd3 Sxd3 9.Lxd3 cxd3 10.Df1 Teg6 
                       11.c4 Kg5 12.Le5 Kh6 13.Df4+ Kh7 
                       14.Th3 Tg1+ 15.Kb2 (306.650.094) 24009 

19/39  0:12   -2.18    2.Dc8 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Kxh4 7.La2 Dc7 
                       8.b5 Tc8 9.Dd1 Tg6 10.a4 Tg4 11.Sf3+ exf3 
                       12.Dxf3 Dc5 13.Te1 Kg5 14.Db7 Dc7 
                       15.Df3 (306.650.094) 24009 

19/29  0:12   -2.21    2.Da7 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Kxh4 7.La2 Dc7 
                       8.b5 Tc8 9.Dd1 Tg6 10.a4 Tg4 11.Sf3+ exf3 
                       12.Dxf3 Kg5 13.La3 Sg6 14.Te1 h4 (306.650.094) 24009 

20/41  0:12   -0.31    2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dd8 
                       5.Sxc2 Dxc7 6.Txc7 Th7 7.Te1 Sf8 
                       8.Se3+ Kxh4 9.Sxf5+ Kg4 10.Se3+ Kxf4 
                       11.Tf1+ Ke5 12.Txh7 Sxh7 13.Tf5+ Kd6 
                       14.Txh5 Sf8 15.Sf5+ (308.612.665) 24012 

20/33  0:12   -0.65    2.Sg2 Lxa8 3.Dxa8 Sg6 4.Dd5 Tf6 
                       5.Dxb5 Sxh4 6.Se1 Td6 7.Dxa4 Kxf4 
                       8.b5 Th7 9.La2 Dg1 10.Dxc4 Tg7 
                       11.Kb1 Kg5 12.a4 Sg6 13.Lb3 h4 
                       14.La3 Tdd7 15.De6 (308.612.665) 24012 

20/35  0:12   -0.73    2.Dxb6 Lxa8 3.Dd4 Sh7 4.Sc2 dxc2 
                       5.Lxc2 Sf6 6.Te1 e3 7.Tg1+ Kf3 
                       8.Txg8 Txg8 9.dxe3 Le4 10.Dd1+ Kf2 
                       11.Dd2+ Kg3 12.Lxe4 Txe4 13.Dd6 Sg4 
                       14.Dd5 Tf8 15.Dxb5 (308.612.665) 24012 

20/39  0:12   -0.94    2.Ta6 Sd7 3.Da7 Kxh4 4.Lc2 dxc2 
                       5.Sxc2 Da8 6.Te1 Dxa7 7.Txa7 Tf6 
                       8.Tg1 e3 9.Sxe3 Th7 10.Tg5 Lf3 
                       11.Sxf5+ Txf5 12.Txf5 Kg3 13.Tg5+ Kf2 (308.612.665) 24012 
...
...
23/34  1:25   0.00     2.Dxf8 Dxf8 3.Txf8 Txf8 4.Sg2 Ld5 
                       5.Lb2 Tg8 6.La2 Ta8 7.Lc1 Tg6 8.Lb2 (2.032.495.812) 23879 

23/36  1:25   -0.39    2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dc8 
                       5.Sxc2 Dxc7 6.Txc7 Sf6 7.Sd4 Ld7 
                       8.Txd7 Sxd7 9.Sxe6 Sf8 10.Sd4 Sg6 
                       11.Te1 Sxh4 12.Tg1+ Kh3 13.Tg7 Th6 
                       14.Kb1 Tg6 15.Tf7 (2.032.495.812) 23879 

23/37  1:25   -0.51    2.Sg2 Lxa8 3.Dxa8 Tg6 4.Da6 Se6 
                       5.Te1 Kf3 6.Dxb5 Sc5 7.bxc5 Txg2 
                       8.c6 Tg1 9.Te3+ Kg4 10.De5 Df8 
                       11.Lb2 Kxh4 12.Dd4 Thg8 13.c7 Dc8 (2.032.495.812) 23879 

23/41  1:25   -1.55    2.Te2 dxe2 3.Dxb6 e3 4.Tc8 Lf3 5.Dd4 Te4 
                       6.Lxe4 fxe4 7.Dxe3 Kxh4 8.d3 Dg3 
                       9.Ld2 cxd3 10.c4 bxc4 11.b5 Sg6 
                       12.Txh8 Sxh8 13.b6 Kh3 14.Lc3 Sg6 
                       15.b7 (2.032.495.812) 23879 

23/36  1:25   -1.70    2.Dxb6 Lxa8 3.Da7 Sh7 4.Lc2 dxc2 
                       5.Sxc2 Kxh4 6.Sd4 Tf6 7.Sc2 Dg2 
                       8.Te1 e3 9.Sxe3 Dg3 10.Tg1 Dxg1 
                       11.Sxf5+ Txf5 12.Dxg1 Te8 13.Dg6 Tff8 
                       14.Dxh7 Lf3 15.Da7 (2.032.495.812) 23879 

23/59  1:25   -1.85    2.Dd8 Lxa8 3.Dd4 Kxh4 4.Sg2+ Kg4 
                       5.Te1 e3 6.Sxe3+ Kh3 7.Lxd3 cxd3 
                       8.Dxd3 Dg3 9.Dxf5+ Kh4 10.Te2 Lf3 
                       11.Sf1 Lxe2 12.Sxg3 Kxg3 13.Dd5 Lf3 
                       14.Dd4 Tg8 15.Dg1+ (2.032.495.812) 23879 

23/48  1:25   -1.86    2.La2 Lxa8 3.Dxa8 Sg6 4.Dd5 Dc8 
                       5.Dxb5 Dc6 6.Dxc4 Dxc4 7.Lxc4 Te7 
                       8.Lb5 Sxf4 9.Lxa4 Tg8 10.c4 Kxh4 
                       11.Lb2 Tg6 12.Ld1 Tee6 13.a4 Tg1 
                       14.Ka2 Sg2 15.Sxg2+ (2.032.495.812) 23879 

23/53  1:25   -1.94    2.Ta6 Sd7 3.Dc7 Kxh4 4.Lc2 dxc2 
                       5.Txb6 Sxb6 6.Dxb6 Kg4 7.Sxc2 h4 
                       8.Te1 Kh5 9.Sd4 Ld5 10.Dxb5 Tf6 
                       11.Dxa4 Th7 12.Kb2 h3 13.Th1 Dg2 
                       14.Dd1+ Kg6 15.Tg1 (2.032.495.812) 23879 

23/48  1:25   -2.10    2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Tg8 7.La2 Kxh4 
                       8.Db5 Tg5 9.Lxc4 Dc6 10.Da6 Tg1 
                       11.Ka2 Tg3 12.Lb3 Teg6 13.a4 Dd7 
                       14.Dc4 Txe3 15.dxe3 (2.032.495.812) 23879 

23/51  1:25   -2.11    2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Se5 
                       5.fxe5 f4 6.Sg2 f3 7.Se1 Tee8 8.Lc2 dxc2 
                       9.Tc7 La8 10.Sxc2 f2 11.Te2 f1D 
                       12.Se3+ Kf3 13.Sxf1 Kxe2 (2.032.495.812) 23879 

23/51  1:25   -2.64    2.Kb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Dxa4 Kxh4 7.Dd7 Dd5 
                       8.Dc7 Kg4 9.Lc2 dxc2 10.d3 h4 
                       11.Txe4 fxe4 12.Dxf4+ Kh5 13.dxe4 De6 
                       14.e5 h3 15.Sf3 (2.032.495.812) 23879 

24/22  1:25   +2.77    2.Dxf8 Dxf8 3.Txf8 Txf8 4.Sg2 Td8 
                       5.La2 Tf8 6.Lb2 Ld5 7.Kb1 Lb7 8.Kc1 Td8 
                       9.Kd1 Tc6 10.Lb1 Td4 11.Ke1 (2.033.495.673) 23880 

23/20  1:25   0.00     2.Ta7 Sd7 3.Dxg8+ Txg8 4.Txd7 Kxh4 
                       5.Tf7 Teg6 6.Lc2 Kg4 7.Sg2 dxc2 
                       8.Kb2 Ld5 9.Th7 T6g7 10.Th6 Tg6 
                       11.Th7 (2.033.495.673) 23880 

23/36  1:25   -0.39    2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dc8 
                       5.Sxc2 Dxc7 6.Txc7 Sf6 7.Sd4 Ld7 
                       8.Txd7 Sxd7 9.Sxe6 Sf8 10.Sd4 Sg6 
                       11.Te1 Sxh4 12.Tg1+ Kh3 13.Tg7 Th6 
                       14.Kb1 Tg6 15.Tf7 (2.033.495.673) 23880 

23/37  1:25   -0.51    2.Sg2 Lxa8 3.Dxa8 Tg6 4.Da6 Se6 
                       5.Te1 Kf3 6.Dxb5 Sc5 7.bxc5 Txg2 
                       8.c6 Tg1 9.Te3+ Kg4 10.De5 Df8 
                       11.Lb2 Kxh4 12.Dd4 Thg8 13.c7 Dc8 (2.033.495.673) 23880 

23/41  1:25   -1.55    2.Te2 dxe2 3.Dxb6 e3 4.Tc8 Lf3 5.Dd4 Te4 
                       6.Lxe4 fxe4 7.Dxe3 Kxh4 8.d3 Dg3 
                       9.Ld2 cxd3 10.c4 bxc4 11.b5 Sg6 
                       12.Txh8 Sxh8 13.b6 Kh3 14.Lc3 Sg6 
                       15.b7 (2.033.495.673) 23880 

23/36  1:25   -1.70    2.Dxb6 Lxa8 3.Da7 Sh7 4.Lc2 dxc2 
                       5.Sxc2 Kxh4 6.Sd4 Tf6 7.Sc2 Dg2 
                       8.Te1 e3 9.Sxe3 Dg3 10.Tg1 Dxg1 
                       11.Sxf5+ Txf5 12.Dxg1 Te8 13.Dg6 Tff8 
                       14.Dxh7 Lf3 15.Da7 (2.033.495.673) 23880 

23/59  1:25   -1.85    2.Dd8 Lxa8 3.Dd4 Kxh4 4.Sg2+ Kg4 
                       5.Te1 e3 6.Sxe3+ Kh3 7.Lxd3 cxd3 
                       8.Dxd3 Dg3 9.Dxf5+ Kh4 10.Te2 Lf3 
                       11.Sf1 Lxe2 12.Sxg3 Kxg3 13.Dd5 Lf3 
                       14.Dd4 Tg8 15.Dg1+ (2.033.495.673) 23880 

23/48  1:25   -1.86    2.La2 Lxa8 3.Dxa8 Sg6 4.Dd5 Dc8 
                       5.Dxb5 Dc6 6.Dxc4 Dxc4 7.Lxc4 Te7 
                       8.Lb5 Sxf4 9.Lxa4 Tg8 10.c4 Kxh4 
                       11.Lb2 Tg6 12.Ld1 Tee6 13.a4 Tg1 
                       14.Ka2 Sg2 15.Sxg2+ (2.033.495.673) 23880 

23/53  1:25   -1.94    2.Ta6 Sd7 3.Dc7 Kxh4 4.Lc2 dxc2 
                       5.Txb6 Sxb6 6.Dxb6 Kg4 7.Sxc2 h4 
                       8.Te1 Kh5 9.Sd4 Ld5 10.Dxb5 Tf6 
                       11.Dxa4 Th7 12.Kb2 h3 13.Th1 Dg2 
                       14.Dd1+ Kg6 15.Tg1 (2.033.495.673) 23880 

23/48  1:25   -2.10    2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Tg8 7.La2 Kxh4 
                       8.Db5 Tg5 9.Lxc4 Dc6 10.Da6 Tg1 
                       11.Ka2 Tg3 12.Lb3 Teg6 13.a4 Dd7 
                       14.Dc4 Txe3 15.dxe3 (2.033.495.673) 23880 

23/51  1:25   -2.11    2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Se5 
                       5.fxe5 f4 6.Sg2 f3 7.Se1 Tee8 8.Lc2 dxc2 
                       9.Tc7 La8 10.Sxc2 f2 11.Te2 f1D 
                       12.Se3+ Kf3 13.Sxf1 Kxe2 (2.033.495.673) 23880 

23/51  1:25   -2.64    2.Kb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Dxa4 Kxh4 7.Dd7 Dd5 
                       8.Dc7 Kg4 9.Lc2 dxc2 10.d3 h4 
                       11.Txe4 fxe4 12.Dxf4+ Kh5 13.dxe4 De6 
                       14.e5 h3 15.Sf3 (2.033.495.673) 23880 

...
...

28/44  4:12   +6.19    2.Dxf8 Dxf8 3.Txf8 Kxf4 4.Txh8 Tg6 
                       5.La2 Lb7 6.Tf8 Ld5 7.Kb2 Lc6 8.Th8 Ld5 
                       9.Td8 Lb7 10.Td4 Lc6 11.Lb1 Le8 
                       12.Sf3 Tg3 13.Sg5 Txe3 14.dxe3+ Kg3 
                       15.Se6 (6.438.282.464) 25472 

28/28  4:12   0.00     2.Ta7 Sd7 3.Dxg8+ Txg8 4.Txd7 Kxh4 
                       5.Tf7 Tg1 6.Lc2 Teg6 7.Ld1 T6g3 
                       8.Txg3 Txe1 9.Tfg7 Txd1 10.Tg1 Txg1 
                       11.Txg1 Kh3 12.Tg6 Le8 13.Te6 Ld7 
                       14.Td6 Le8 15.Te6 (6.438.282.464) 25472 

28/58  4:12   -0.76    2.Lc2 dxc2 3.Ta7 Sd7 4.Dc7 Dd8 
                       5.Sxc2 Dxc7 6.Txc7 Sf8 7.Te1 Th7 
                       8.Se3+ Kxh4 9.Txh7 Sxh7 10.Th1+ Kg3 
                       11.Txh5 Sf6 12.Txf5 Le8 13.Kb1 Sh5 
                       14.Ka1 Kf3 15.Kb1 (6.438.282.464) 25472 

28/62  4:12   -1.38    2.Sg2 Lxa8 3.Dxa8 Tg6 4.Db7 Se6 
                       5.Dd7 Dc8 6.Dxb5 Sxf4 7.Sxf4 Kxf4 
                       8.Te1 De6 9.Tf1+ Kg4 10.La2 Tc8 
                       11.Dxa4 f4 12.Tg1+ Kh3 13.Th1+ Kg3 
                       14.Dd1 f3 15.De1+ (6.438.282.464) 25472 

28/69  4:12   -2.00    2.Dxb6 Lxa8 3.Dxb5 Sg6 4.Sg2 De8 
                       5.Dxc4 Dc6 6.Dd4 Td6 7.Da7 Dd7 8.Da5 Sxh4 
                       9.Sxh4 Kxh4 10.c4 Tg6 11.Te1 Thg8 
                       12.Lb2 Tg3 13.Db6 Kg4 14.b5 h4 
                       15.Dh6 (6.438.282.464) 25472 

27/60  4:12   -2.19    2.Dd8 Lxa8 3.Dd4 Kxh4 4.Sg2+ Kg4 
                       5.Te1 e3 6.Sxe3+ Kh3 7.Lxd3 cxd3 
                       8.Dxd3 Dg3 9.Dxf5+ Kh4 10.Te2 Lf3 
                       11.Sf1 Lxe2 12.Sxg3 Kxg3 13.Dd5 Lf3 
                       14.Dd4 Tg8 15.Dg1+ (6.438.282.464) 25472 

27/50  4:12   -2.26    2.La2 Lxa8 3.Dxa8 Sg6 4.Dd5 Dc8 
                       5.Dxb5 Dc6 6.Dxc4 Td6 7.Df7 Dd7 
                       8.Dxd7 Txd7 9.Lc4 Sxf4 10.Lb5 Tc7 
                       11.c4 Thc8 12.Lxa4 Txc4 13.Lb2 Kxh4 
                       14.Le5 Se2 15.Ld7 (6.438.282.464) 25472 

27/60  4:12   -2.29    2.Ta6 Sd7 3.Dc7 Kxh4 4.Lc2 dxc2 
                       5.Sxc2 Dd8 6.Dxd8+ Txd8 7.Sd4 Tf6 
                       8.Ta7 Ld5 9.Tc7 Sf8 10.Tg7 Sg6 
                       11.Te1 Tg8 12.Td7 Sxf4 13.Tf1 Kg3 
                       14.d3 Sxd3 15.Txd5 (6.438.282.464) 25472 

27/55  4:12   -2.60    2.Txa4 Sd7 3.Dxg8+ Txg8 4.Ta7 Se5 
                       5.fxe5 f4 6.Sg2 f3 7.Se1 Tee8 8.Tc7 La8 
                       9.Lc2 dxc2 10.Sxc2 f2 11.Te2 f1D 
                       12.Se3+ Kf3 13.Tf7+ Kxe2 14.Txf1 Tgf8 
                       15.Tg1 (6.438.282.464) 25472 

27/52  4:12   -2.90    2.Lb2 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Dc8 6.Dxa4 Tg8 7.Dd1+ Kxh4 
                       8.Sxd3 Sxd3 9.Lxd3 cxd3 10.Df1 Kg5 
                       11.c4 f4 12.Te1 De8 13.Tc1 Df7 
                       14.Ld4 Kh6 15.Df2 (6.438.282.464) 25472 

27/47  4:12   -2.97    2.Sc2 Lxa8 3.Dxa8 Td6 4.Da6 Sg6 
                       5.Sd4 Txd4 6.cxd4 Sxh4 7.Te1 Sf3 
                       8.Th1 Th6 9.Dxb5 h4 10.Lb2 h3 11.Lc3 h2 
                       12.d5 Db8 13.Dxc4 Dxf4 14.Dc8 Kh3 
                       15.Dg8 (6.438.282.464) 25472 

27/58  4:12   -3.37    2.Dc8 Lxa8 3.Dxa8 Sg6 4.Dd5 Sxf4 
                       5.Dxb5 Tg6 6.Dxa4 Kxh4 7.Dd7 Dd5 
                       8.Dc7 Kg4 9.Lc2 dxc2 10.d3 Dd6 
                       11.Dxc4 b5 12.Df7 h4 13.dxe4 De6 
                       14.Dxf5+ Dxf5 15.exf5 (6.438.282.464) 25472

Bester Zug: Db8xf8 Zeit: 4:14.969 min K/s: 25.472.020 Knoten: 6.438.282.464

acase · Post by **acase** » Fri Mar 31, 2023 2:22 pm

Jouni wrote: ↑Fri Mar 31, 2023 8:48 am Analysis by Stockfish dev-20230319-02e46970

1.fxe5 Bc6 2.Ne6 f4 3.Nexf4 Kf5 4.e6 Kf6 5.Rg3 b5 6.Rg6+ Kf5 7.Rg5+ Kf6 8.Ne3 Ke7 9.Rg6 Be8 10.Rg8 Bc6 11.Rc8 Kd6 12.e7 Bd7 13.e8Q Bxe8 14.Rxe8 Kc6 15.Rxe4 Kc7 16.Ned5+ Kb7 17.Re6 Ka7 18.Rb6 Ka8 19.Rxa6+ Kb8 20.Re6 Kb7
+- (#34) Depth: 39/48 00:05:54 3783mN, tb=41297

Hi Jouni,

Stockfish 8 is finds a "shorter" mate faster on that mate in 5 problem

FEN: 8/2Nb4/pp6/4rp1p/1Pp1pPkP/PpPpR3/1B1P2N1/1K6 w - - 0 1

Stockfish_8_x64_bmi2:
42/53 00:30 1,173,680k 38,851k +M22 1.f4xe5 f5-f4 2.Ng2xf4 Kg4xf4 3.e5-e6 Bd7-c6 4.e6-e7 Kf4-e5 5.e7-e8Q+ Bc6xe8 6.Nc7xe8 Ke5-f5 7.Ne8-g7+ Kf5-g6 8.Re3-g3+ Kg6-f6 9.Ng7xh5+ Kf6-f5 10.Rg3-g5+ Kf5-e6 11.Nh5-f4+ Ke6-d7 12.h4-h5 e4-e3 13.d2xe3 d3-d2 14.Rg5-d5+ Kd7-c6 15.h5-h6 d2-d1R+ 16.Rd5xd1 a6-a5 17.h6-h7 a5xb4 18.a3xb4 Kc6-c7 19.h7-h8Q Kc7-b7 20.Rd1-d7+ Kb7-c6 21.Qh8-e8 Kc6-b5 22.Rd7-a7+

Jouni · Post by **Jouni** » Fri Mar 31, 2023 3:05 pm

After fxe5 Huntsman thinks it's mate in 20:

1...f4 2.Rxe4 Kf5 3.Rxc4 Kxe5 4.Rd4 Bc6 5.Nxf4 Be4 6.Nxh5 Bg6 7.Ng3 b5 8.h5 Bxh5 9.Nxh5 Kf5 10.c4 Kg5 11.c5 a5 12.Ng3 a4 13.Ne6+ Kf6 14.c6 Kxe6 15.c7 Kf6 16.Rxd3+ Kg5 17.c8Q Kh6 18.Qe6+ Kg5 19.Qf5+ Kh4 20.Bf6#

Nice study by Troitsky

Re: Nice study by Troitsky.

Re: Nice study by Troitsky.

Re: Nice study by Troitsky

Re: Nice study by Troitsky

Re: Nice study by Troitsky.

Re: Nice study by Troitsky.

Re: Nice study by Troitsky

Re: Nice study by Troitsky

Re: Nice study by Troitsky

Re: Nice study by Troitsky