Looking for a mechanical solution to 11 Epd problems

[zullil]

Hi Louis!

Very nice position indeed!

Made a .pgn about it:

Code: Select all

[Event "CCC"]
[Site "?"]
[Date "2015.04.25"]
[Round "?"]
[White "Corbit, Dann"]
[Black "Zulli, Louis"]
[Result "1-0"]
[SetUp "1"]
[FEN "4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - -"]

1. Qxe5 $1 (1. Qa3 $2 Rxe6 2. Qxa7 Qe7 3. Qa8+ Qe8 4. Qb7 
Qe7 5. Qa8+ Qe8) 1... fxe5 2. Rf1 Rc8 (2... a6 3. Bd1 b5 
(3... Rc7 4. Bb3 Re7 5. Bd5 b5 6. Kg2 a5 7. a3 b4 8. axb4 
Qb8 9. b5 Qe8 10. b6 a4 11. b7 a3 12. Rf7 axb2 13. Rxe7 Qb5 
14. Re8+ Qxe8 15. e7+ Qf7 16. e8=Q#) 4. Bb3 Rc4 5. a4 Qe7 
6. Kg2) 3. Bd1 b5 4. Bb3 Rc4 5. a4 (5. Rf3) (5. a3 a6 6. a4 
Qe7 7. Kg2 Qe8 8. Rf3 (8. h3) 8... Qd8) 5... a6 6. Ba2 Qe7 
7. Kg2 Qg7 8. Bxc4 bxc4 9. Bxg7 Kxg7 10. Rf7+ 1-0

This position is from the game below, or available at http://www.chessgames.com/perl/chessgame?gid=1472988

Here is the position after Black's 23rd move, with SF's current PV:
[d]4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - - 1 24

Code: Select all

info depth 50 seldepth 81 multipv 1 score cp 397 nodes 940558094988 nps 27958134 hashfull 999 tbhits 0 time 33641661 pv d6e5 f6e5 a1f1 a7a6 e2d1 b6b5 d1b3 c6c4 a2a4 e8e7 g1g2 e7e8 f1f3 e8e7 b3a2 e7g7 h6g7 g8g7 a2c4 b5c4 f3f7 g7h6 e6e7 h8e8 g2g3 g6g5 f7f6 h6g7 f6a6 e8e7 g3g4 e7b7 g4g5 g7f7 g5f5 b7b2 a6a7 f7e8 a4a5 e8d8 a5a6 b2a2 f5e5 d8c8 e5d5 c8b8 a7h7 a2a6 h2h4 b8c8 h4h5 c8d8 d5c4 d8e8 c4d5 a6a5 d5d4 e8f8 e4e5 a5a6 h5h6 f8g8 h7g7 g8h8

This PV was obtained by having SF search the position after 24. Qxe5 fxe5 (with 16 threads, 16 GB hash and null move pruning disbaled) until it saw a promising continuation for White. The search was then stopped but the hash table was left intact, and SF was given the position above. In short, "cheating" was involved. I don't know how long SF would take to find the key move Qxe5 with an empty hash table. But, in any case, we now have strong evidence that the sacrifice is sound, and wins with correct play.

[pgn]
[Event "Molniya Sporting Society"]
[Site "Chelyabinsk RUS"]
[Date "1946.??.??"]
[EventDate "?"]
[Round "5"]
[Result "1-0"]
[White "Yuri S Gusev"]
[Black "E Auerbach"]
[ECO "B70"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "73"]

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be2 Nc6 7.Nb3
Bg7 8.O-O Be6 9.f4 Rc8 10.f5 Bd7 11.g4 Ne5 12.g5 Ng8 13.Nd5 f6
14.Be3 b6 15.Nd4 Kf7 16.c3 Qe8 17.Ne6 Bxe6 18.fxe6+ Kf8
19.Nxf6 Nxf6 20.gxf6 Bxf6 21.Bh6+ Kg8 22.Rxf6 exf6 23.Qxd6 Rc6
24.Qxe5 fxe5 25.Rf1 Rc8 26.Bd1 Rc4 27.Bb3 b5 28.Bxc4 bxc4
29.b3 a5 30.bxc4 Qe7 31.Kg2 Qa3 32.Rf2 Qe7 33.Rf1 g5 34.Rf5 g4
35.c5 Qd8 36.c6 Qe7 37.c7 1-0
[/pgn]

Another iteration:

Code: Select all

info depth 51 seldepth 81 multipv 1 score cp 434 nodes 1757470949487 nps 27901569 hashfull 999 tbhits 0 time 62988247 pv d6e5 f6e5 a1f1 e8e7 e2d1 c6c4 d1b3 b6b5 a2a4 a7a6 g1g2 e7e8 f1f3 e8e7 b3a2 e7g7 a2c4 b5c4 h6g7 g8g7 f3f7 g7h6 e6e7 h8e8 g2g3 g6g5 f7f6 h6g7 f6a6 e8e7 g3g4 e7b7 g4g5 g7f7 g5f5 b7b2 a6a7 f7e8 a4a5 e8d8 a5a6 b2a2 f5e5 d8c8 e5d6 c8b8 a7b7 b8a8 b7h7 a2a6 d6d5 a8b8 h2h4 b8c8 h4h5 c8d8 h5h6 d8e8 e4e5 a6g6 e5e6 e8f8 h7f7 f8e8 h6h7 g6h6 d5c4 h6h3

[zullil]

Hi Louis!

Very nice position indeed!

Made a .pgn about it:

Code: Select all

[Event "CCC"]
[Site "?"]
[Date "2015.04.25"]
[Round "?"]
[White "Corbit, Dann"]
[Black "Zulli, Louis"]
[Result "1-0"]
[SetUp "1"]
[FEN "4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - -"]

1. Qxe5 $1 (1. Qa3 $2 Rxe6 2. Qxa7 Qe7 3. Qa8+ Qe8 4. Qb7 
Qe7 5. Qa8+ Qe8) 1... fxe5 2. Rf1 Rc8 (2... a6 3. Bd1 b5 
(3... Rc7 4. Bb3 Re7 5. Bd5 b5 6. Kg2 a5 7. a3 b4 8. axb4 
Qb8 9. b5 Qe8 10. b6 a4 11. b7 a3 12. Rf7 axb2 13. Rxe7 Qb5 
14. Re8+ Qxe8 15. e7+ Qf7 16. e8=Q#) 4. Bb3 Rc4 5. a4 Qe7 
6. Kg2) 3. Bd1 b5 4. Bb3 Rc4 5. a4 (5. Rf3) (5. a3 a6 6. a4 
Qe7 7. Kg2 Qe8 8. Rf3 (8. h3) 8... Qd8) 5... a6 6. Ba2 Qe7 
7. Kg2 Qg7 8. Bxc4 bxc4 9. Bxg7 Kxg7 10. Rf7+ 1-0

This position is from the game below, or available at http://www.chessgames.com/perl/chessgame?gid=1472988

Here is the position after Black's 23rd move, with SF's current PV:
[d]4q1kr/p6p/1prQPppB/4n3/4P3/2P5/PP2B2P/R5K1 w - - 1 24

Code: Select all

info depth 50 seldepth 81 multipv 1 score cp 397 nodes 940558094988 nps 27958134 hashfull 999 tbhits 0 time 33641661 pv d6e5 f6e5 a1f1 a7a6 e2d1 b6b5 d1b3 c6c4 a2a4 e8e7 g1g2 e7e8 f1f3 e8e7 b3a2 e7g7 h6g7 g8g7 a2c4 b5c4 f3f7 g7h6 e6e7 h8e8 g2g3 g6g5 f7f6 h6g7 f6a6 e8e7 g3g4 e7b7 g4g5 g7f7 g5f5 b7b2 a6a7 f7e8 a4a5 e8d8 a5a6 b2a2 f5e5 d8c8 e5d5 c8b8 a7h7 a2a6 h2h4 b8c8 h4h5 c8d8 d5c4 d8e8 c4d5 a6a5 d5d4 e8f8 e4e5 a5a6 h5h6 f8g8 h7g7 g8h8

This PV was obtained by having SF search the position after 24. Qxe5 fxe5 (with 16 threads, 16 GB hash and null move pruning disbaled) until it saw a promising continuation for White. The search was then stopped but the hash table was left intact, and SF was given the position above. In short, "cheating" was involved. I don't know how long SF would take to find the key move Qxe5 with an empty hash table. But, in any case, we now have strong evidence that the sacrifice is sound, and wins with correct play.

[pgn]
[Event "Molniya Sporting Society"]
[Site "Chelyabinsk RUS"]
[Date "1946.??.??"]
[EventDate "?"]
[Round "5"]
[Result "1-0"]
[White "Yuri S Gusev"]
[Black "E Auerbach"]
[ECO "B70"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "73"]

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be2 Nc6 7.Nb3
Bg7 8.O-O Be6 9.f4 Rc8 10.f5 Bd7 11.g4 Ne5 12.g5 Ng8 13.Nd5 f6
14.Be3 b6 15.Nd4 Kf7 16.c3 Qe8 17.Ne6 Bxe6 18.fxe6+ Kf8
19.Nxf6 Nxf6 20.gxf6 Bxf6 21.Bh6+ Kg8 22.Rxf6 exf6 23.Qxd6 Rc6
24.Qxe5 fxe5 25.Rf1 Rc8 26.Bd1 Rc4 27.Bb3 b5 28.Bxc4 bxc4
29.b3 a5 30.bxc4 Qe7 31.Kg2 Qa3 32.Rf2 Qe7 33.Rf1 g5 34.Rf5 g4
35.c5 Qd8 36.c6 Qe7 37.c7 1-0
[/pgn]

Another iteration:

Code: Select all

info depth 51 seldepth 81 multipv 1 score cp 434 nodes 1757470949487 nps 27901569 hashfull 999 tbhits 0 time 62988247 pv d6e5 f6e5 a1f1 e8e7 e2d1 c6c4 d1b3 b6b5 a2a4 a7a6 g1g2 e7e8 f1f3 e8e7 b3a2 e7g7 a2c4 b5c4 h6g7 g8g7 f3f7 g7h6 e6e7 h8e8 g2g3 g6g5 f7f6 h6g7 f6a6 e8e7 g3g4 e7b7 g4g5 g7f7 g5f5 b7b2 a6a7 f7e8 a4a5 e8d8 a5a6 b2a2 f5e5 d8c8 e5d6 c8b8 a7b7 b8a8 b7h7 a2a6 d6d5 a8b8 h2h4 b8c8 h4h5 c8d8 h5h6 d8e8 e4e5 a6g6 e5e6 e8f8 h7f7 f8e8 h6h7 g6h6 d5c4 h6h3

Another:

Code: Select all

info depth 52 seldepth 87 multipv 1 score cp 400 nodes 3709335640773 nps 28088666 hashfull 999 tbhits 0 time 132058090 pv d6e5 f6e5 a1f1 a7a6 e2d1 b6b5 d1b3 c6c4 g1g2 e8a8 g2g3 a8e8 a2a4 e8e7 g3g2 e7g7 h6g7 g8g7 b3c4 b5c4 f1f7 g7h6 e6e7 h8e8 g2g3 g6g5 f7f6 h6g7 f6a6 e8e7 g3g4 e7f7 g4g5 h7h6 a6h6 f7a7 h6b6 a7a4 b6b7 g7f8 g5f6 a4a8 f6e5 a8d8 h2h4 d8d2 h4h5 d2h2 e5d5 h2h5 d5c4 h5e5 c4d4 e5e8 e4e5 e8d8 d4e4 d8d1 b2b4 d1e1 e4d5 e1d1 d5e6 d1c1 b7c7 c1b1 e6d5 b1d1 d5c4