Difficult position for Stockfish

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S.Taylor
Posts: 7819
Joined: Thu Mar 09, 2006 2:25 am
Location: Jerusalem Israel

Re: Difficult position for Stockfish

Post by S.Taylor » Fri Feb 17, 2017 2:32 pm

Paloma wrote:Hmm, I have here matt in 24. 8-)

Forward / backward with DeepShredder13 without TB's

[pgn]
[Event "Quirky"]
[Site "?"]
[Date "2014.06.26"]
[Round "?"]
[White "Quirky 16"]
[Black "?"]
[Result "0-1"]
[Annotator "?"]
[SetUp "1"]
[FEN "6Q1/8/3p4/2pPk1p1/1p5P/1P4PK/2q5/8 b - - 0 1"]
[PlyCount "11"]

1... g4+ $1 2. Qxg4 Qf5 3. h5 (3. Qxf5+ Kxf5 4. g4+ Kg6 5. Kg3 c4 6. bxc4 b3) 3... Qxg4+ 4. Kxg4 c4 5. bxc4 b3
6. h6 Kf6 0-1
[/pgn]

1... g4+ $1 {24#} 2. Qxg4 Qf5 3. h5 (3. Qxf5+ Kxf5 {21#} 4. g4+ Kg6 {20#} 5. Kg3 c4 6. bxc4 b3 {18#})
3... Qxg4+ {22#} 4. Kxg4 c4 {21#} 5. bxc4 b3 6. h6 Kf6 {19#} 0-1
Mate hardly matters. The main thing is that black is a move ahead and gets back just in time to stop white queening.
I'd be surprised if SF failed to win just because he didn't see the actual mate.
1...g4! does look quite important.

flok

Re: Difficult position for Stockfish

Post by flok » Fri Feb 17, 2017 3:00 pm

Embla 0.9.8:

Code: Select all

info depth 1 seldepth 7 score cp 94 time 1 nodes 21 pv g5h4
info depth 2 seldepth 10 score cp 86 time 1 nodes 283 pv c2f5 h3h2 f5c2 h2g1 g5h4
info depth 3 seldepth 12 score cp 86 ebf 4.68 time 2 nodes 742 pv c2f5 h3h2 f5c2 h2g1 g5h4
info depth 4 seldepth 15 score cp 86 ebf 2.03 time 5 nodes 1819 pv c2f5 h3h2 f5c2 h2g1 c2b1 g1h2 b1b2 h2g1 g5h4
info depth 5 seldepth 16 score cp 86 ebf 2.54 time 15 nodes 4783 pv c2f5 h3h2 f5c2 h2g1 c2b1 g1h2 b1b2 h2g1 g5h4
info depth 6 seldepth 19 score cp 91 ebf 3.06 time 40 nodes 14851 pv c2f5 h3h2 g5h4 g8h8 e5d5 h8a8 d5e5 a8a1 e5e6 g3h4
info depth 7 seldepth 23 score cp 82 ebf 2.30 time 75 nodes 30560 pv c2f5 h3h2 g5h4 g3h4 f5c2 h2g1 c2d1 g1g2 d1d2 g2g1 d2d4 g1h2 d4h4 h2g1
info depth 8 seldepth 26 score cp 75 ebf 1.66 time 134 nodes 58155 pv c2f5 h3h2 g5h4 g3h4 f5c2 g8g2 c2g2 h2g2 e5d5
info depth 9 seldepth 28 score cp 85 ebf 3.52 time 567 nodes 252438 pv g5h4 h3h4 c2e4 g3g4 e4d5 g8d5 e5d5 g4g5 c5c4 b3c4 d5c4 g5g6

BBauer
Posts: 655
Joined: Wed Mar 08, 2006 7:58 pm

Re: Difficult position for Stockfish

Post by BBauer » Fri Feb 17, 2017 3:19 pm

IMHO this is not difficult for SF.

At least 3 moves lead to a win.
1. ... g4
1. ... Qf5
1. ... gxh4
SF will choose a winning continuation and win without any problems,

Kind regars
Bernhard

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Nordlandia
Posts: 2037
Joined: Fri Sep 25, 2015 7:38 pm
Location: Sortland, Norway

Re: Difficult position for Stockfish

Post by Nordlandia » Sat Feb 18, 2017 10:30 am

[d]6N1/Rp4p1/3q3p/1B3P1k/5P2/5K2/1P1r1N1P/8 w - - 0 0

[pgn][Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "New game"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "6N1/Rp4p1/3q3p/1B3P1k/5P2/5K2/1P1r1N1P/8 w - - 0 0"]
[PlyCount "15"]

1. Be2 Qd5+ 2. Ke3+ Kh4 3. Ne7 Qd4+ 4. Kf3 Rxe2 5. Kxe2 Qxa7 6. Ng6+ Kh5 7. Ne5
Qd4 8. Ned3 *

[/pgn]

Vinvin
Posts: 4027
Joined: Thu Mar 09, 2006 8:40 am

Re: Difficult position for Stockfish

Post by Vinvin » Sat Feb 18, 2017 10:33 pm

Jouni wrote:[D]6Q1/8/3p4/2pPk1p1/1p5P/1P4PK/2q5/8 b - - 0 1

Well-known from many test suites. Houdini and Komodo find mating -g4+ almost instantly, but SF8 not in 5 minutes. I gave up :) .
With enough time, SF would probably finds a mate score for g4+ and Qf5+

Code: Select all

Stockfish_170214_x64_modern_fast:
...
 38/108	00:40	 778 677k	19 171k	-61,44	1. ... Qf5+ 2.Kg2 g4 3.Qg7+ Ke4 4.Kg1 Qf3 5.Qe7+ Kxd5 6.Qe1 Qc3 7.Qf2 Qd4 8.h5 Qxf2+ 9.Kxf2 Ke5 10.h6 Kf6 11.h7 Kg7 12.h8R Kxh8 13.Ke3 Kh7 14.Ke4 Kg6 15.Kd3 Kh5 16.Kc2 Kg5 17.Kd2 Kf5 18.Kd3 Ke5 19.Kc4 Ke4 20.Kb5 Kd5 21.Ka5 Kc6 22.Ka6 c4 23.bxc4 Kc5 24.Ka5 b3
 39/108	00:40	 778 677k	19 171k	-M29	1. ... g4+ 2.Qxg4 Qf5 3.h5 Qxg4+ 4.Kxg4 c4 5.h6 Kf6 6.bxc4 b3 7.c5 b2 8.h7 Kg7 9.cxd6 b1Q 10.Kf4 Kxh7 11.d7 Qb4+ 12.Kf5 Qe7 13.d8N Qxd8 14.Ke5 Qg5+ 15.Ke4 Qxg3 16.Kd4 Kg7 17.Kc4 Kg6 18.Kd4 Kf6 19.Ke4 Qb3 20.Kd4 Qd1+ 21.Ke4 Qd2 22.Kf3 Qxd5+ 23.Kg3 Ke5 24.Kf2 Qd2+ 25.Kg3 Kf6 26.Kf3 Kf5 27.Kg3 Qe2

Vinvin
Posts: 4027
Joined: Thu Mar 09, 2006 8:40 am

Re: Difficult position for Stockfish

Post by Vinvin » Sat Feb 18, 2017 11:52 pm

Vinvin wrote:
Jouni wrote:[D]6Q1/8/3p4/2pPk1p1/1p5P/1P4PK/2q5/8 b - - 0 1

Well-known from many test suites. Houdini and Komodo find mating -g4+ almost instantly, but SF8 not in 5 minutes. I gave up :) .
With enough time, SF would probably finds a mate score for g4+ and Qf5+

Code: Select all

Stockfish_170214_x64_modern_fast:
...
 38/108	00:40	 778 677k	19 171k	-61,44	1. ... Qf5+ 2.Kg2 g4 3.Qg7+ Ke4 4.Kg1 Qf3 5.Qe7+ Kxd5 6.Qe1 Qc3 7.Qf2 Qd4 8.h5 Qxf2+ 9.Kxf2 Ke5 10.h6 Kf6 11.h7 Kg7 12.h8R Kxh8 13.Ke3 Kh7 14.Ke4 Kg6 15.Kd3 Kh5 16.Kc2 Kg5 17.Kd2 Kf5 18.Kd3 Ke5 19.Kc4 Ke4 20.Kb5 Kd5 21.Ka5 Kc6 22.Ka6 c4 23.bxc4 Kc5 24.Ka5 b3
 39/108	00:40	 778 677k	19 171k	-M29	1. ... g4+ 2.Qxg4 Qf5 3.h5 Qxg4+ 4.Kxg4 c4 5.h6 Kf6 6.bxc4 b3 7.c5 b2 8.h7 Kg7 9.cxd6 b1Q 10.Kf4 Kxh7 11.d7 Qb4+ 12.Kf5 Qe7 13.d8N Qxd8 14.Ke5 Qg5+ 15.Ke4 Qxg3 16.Kd4 Kg7 17.Kc4 Kg6 18.Kd4 Kf6 19.Ke4 Qb3 20.Kd4 Qd1+ 21.Ke4 Qd2 22.Kf3 Qxd5+ 23.Kg3 Ke5 24.Kf2 Qd2+ 25.Kg3 Kf6 26.Kf3 Kf5 27.Kg3 Qe2
I finally got a mate score for both moves :

Code: Select all

 40/101	03:32	 4 085 904k	19 258k	-M54	1. ... Qf5+ 2.Kg2 g4 3.Qg7+ Ke4 4.Kg1 Kd3 5.Qb2 Qf3 6.Kh2 Qf1 7.h5 Qh3+ 8.Kg1 Qxg3+ 9.Qg2 Qe1+ 10.Kh2 Qh4+ 11.Kg1 Qxh5 12.Qf1+ Kd4 13.Qc4+ Ke5 14.Qe2+ Kxd5 15.Qg2+ Ke5 16.Qf2 Qf5 17.Qb2+ Ke6 18.Qe2+ Kf6 19.Qd2 Qe5 20.Qf2+ Ke6 21.Kg2 Qd5+ 22.Kg1 Qd1+ 23.Kh2 Qxb3 24.Qe1+ Kf5 25.Qf2+ Ke4 26.Qg2+ Qf3 27.Qa2 Qc3 28.Qa8+ Kd3 29.Qa6+ Kc2 30.Qa2+ Kc1 31.Qa5 Qh3+ 32.Kg1 Qe3+ 33.Kh1 b3 34.Qa1+ Kc2 35.Qa4 Qd4 36.Qc6 b2 37.Qg2+ Kd3 38.Qf1+ Kc3 39.Qb1 Qd3 40.Qe1+ Qd2 41.Qf1 Qc1 42.Qxc1+ bxc1Q+ 43.Kh2
 41/101	03:32	 4 085 904k	19 258k	-M29	1. ... g4+ 2.Qxg4 Qf5 3.h5 Qxg4+ 4.Kxg4 c4 5.h6 Kf6 6.h7 Kg7 7.bxc4 b3 8.Kf5 b2 9.Ke6 b1Q 10.Kxd6 Qb6+ 11.Kd7 Kxh7 12.d6 Kg7 13.Ke6 Qc6 14.Ke5 Qxc4 15.d7 Qc7+ 16.Ke6 Qc6+ 17.Kf5 Qxd7+ 18.Ke5 Qc7+ 19.Kd5 Qxg3 20.Kd4 Qd6+ 21.Kc4 Kf6 22.Kb5 Qd3+ 23.Kb6 Qc4 24.Kb7 Ke5 25.Ka8 Kd6 26.Ka7 Qa4+ 27.Kb7 Qb3+ 28.Ka6 Kc6 29.Ka5 Qa3+

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Nordlandia
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Re: Difficult position for Stockfish

Post by Nordlandia » Sun Feb 19, 2017 3:28 pm

[d]4k3/2pp1R1p/1pN1P3/3rP3/1K6/B2P4/3p2p1/1b1r4 w - - 0 0

4. Ng6+ is the trump card!

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Nordlandia
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Re: Difficult position for Stockfish

Post by Nordlandia » Mon Feb 20, 2017 8:42 am

[d]8/3k4/R1n3K1/2pN4/2P2P1r/8/8/8 w - - 0 1

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