Can engines find the correct move in this position?

[Damir]

Here is the position:

[fen]r1bqk1nr/pp1pnppp/1bp5/1B6/3PP3/5N2/PP3PPP/RNBQ1RK1 w kq - 0 8[/fen]

It is White to move.

The correct move is 8.d5 with +1.52 advantage for White.

Lc0 and latest SF find the correct 8.d5 move almost instantly with +1.52 score while Dragon does not seem to find it and want to play Bd3 instead..

[Ajedrecista]

Hello Damir:

It is incredible that after 8. d5 cxb5 9. d6, black is a full bishop ahead without immediate recaptures or mate threats against, yet SF 15 evaluates the position as slightly better for white! Analysis after 8. d5 cxb5 9. d6 by SF 15 with Multi-PV = 7:

Code: Select all

FEN: r1bqk1nr/pp1pnppp/1b1P4/1p6/4P3/5N2/PP3PPP/RNBQ1RK1 b kq - 0 9 

Stockfish_15_x64_popcnt:
[...]
---------------------------------------------------------------------------
 37/46	36:44	1.748.606.167	793.040	-1,58	Ra8b8 Bc1g5 f7f6 d6xe7 Ng8xe7 Bg5f4 d7d6 Nb1c3 Bc8e6 Nc3xb5 OO Qd1xd6 Qd8xd6 Bf4xd6 Be6c4 Bd6xe7 Bc4xb5 Be7xf8 Bb5xf1 Kg1xf1 Rb8xf8 Ra1c1 Rf8d8 Kf1e2 Kg8f7 Rc1c4 Rd8e8 a2a4 Re8e7 g2g3 f6f5 Nf3d2 f5xe4 Rc4xe4 Re7xe4+ Nd2xe4 Kf7e6 Ne4g5+ Ke6f5 Ng5xh7
 37/49	36:44	1.748.606.167	793.040	-1,57	a7a5 Nb1c3 b5b4 Nc3b5 Ne7c6 Bc1g5 f7f6 Bg5e3 Bb6xe3 f2xe3 Ke8f8 Nb5c7 Ra8a7 e4e5 b7b6 Nc7b5 Ra7b7 Ra1c1 Qd8e8 Qd1d5 g7g6 Nf3d4 Nc6xe5 Rc1xc8 Qe8xc8 Qd5xe5 Qc8c5 Qe5f4 Rb7b8 Nb5c7 g6g5 Qf4g3 Rb8e8 Nc7xe8 Kf8xe8 Qg3f3 Qc5xd6 Qf3a8+ Ke8f7 Nd4f5 Qd6e5 Qa8d8 h7h5 Qd8xd7+ Ng8e7 e3e4
 37/53	36:44	1.748.606.167	793.040	-1,53	Ke8f8 d6xe7+ Ng8xe7 e4e5 Ne7f5 Bc1f4 h7h6 Nb1c3 g7g5 Bf4e3 d7d6 Be3xb6 a7xb6 h2h3 Kf8g7 g2g4 d6xe5 g4xf5 Bc8xf5 Nf3xe5 Qd8xd1 Rf1xd1 Rh8d8 a2a3 Bf5xh3 Ra1c1 f7f6 Ne5f3 Bh3g4 Kg1g2 h6h5 Nc3xb5 Ra8c8 Rc1c7+ Rc8xc7 Rd1xd8 Rc7c1 Rd8b8
 37/51	36:44	1.748.606.167	793.040	-1,26	b5b4 a2a3 Ne7g6 e4e5 f7f6 Rf1e1 f6xe5 Nf3xe5 Ke8f8 a3xb4 Qd8h4 Ne5f3 Bb6xf2+ Kg1h1 Qh4xb4 Re1f1 Ng8f6 Rf1xf2 b7b5 Nb1c3 Bc8b7 Nf3d4 Kf8g8 Nc3xb5 a7a6 Ra1a4 Qb4c5 Rf2f5 Nf6d5 Nb5c3 Nd5xc3 b2xc3 Qc5xc3 Nd4e2 Qc3h3 Rf5g5 Ra8f8 Ne2f4 Ng6xf4 Ra4xf4 Qh3e6 Rf4xf8+ Kg8xf8
 37/51	36:44	1.748.606.167	793.040	-0,97	Ne7g6 e4e5 Ke8f8 Nb1c3 Qd8e8 Bc1d2 Ng6xe5 Nf3xe5 Qe8xe5 Rf1e1 Qe5f5 Qd1e2 Qf5xf2+ Qe2xf2 Bb6xf2+ Kg1xf2 b7b6 Nc3xb5 Bc8b7 Kf2g1 h7h5 Ra1c1 Ng8f6 Rc1c7 Bb7d5 Bd2g5 h5h4 Nb5d4 Bd5xa2 Bg5xf6 g7xf6 b2b3 Rh8h5 Rc7xd7 Rh5d5 Re1e7 Rd5xd4 Re7xf7+ Kf8g8 Rf7g7+ Kg8h8 Rg7h7+ Kh8g8
 37/48	36:44	1.748.606.167	793.040	-0,93	h7h6 e4e5 Ne7c6 Nb1c3 b5b4 Nc3d5 Ng8e7 d6xe7 Nc6xe7 Nd5xb6 Qd8xb6 Bc1e3 Qb6b5 Rf1e1 OO Nf3h4 d7d5 e5xd6/ep Ne7f5 Nh4xf5 Qb5xf5 Ra1c1 Rf8d8 Rc1c4 Bc8d7 Rc4xb4 Qf5g6 Be3f4 Rd8e8 Re1xe8+ Ra8xe8 f2f3 Bd7c6 Bf4g3 Qg6e6 Rb4d4 Bc6d7 Rd4e4 Qe6f5 Re4c4 Bd7c6 Bg3f2 a7a6 Rc4xc6 b7xc6 d6d7
 37/48	36:44	1.748.606.167	793.040	-0,85	Ne7c6 Nb1c3 h7h6 e4e5 b5b4 Nc3d5 Ng8e7 d6xe7 Nc6xe7 Nd5xb6 Qd8xb6 Bc1e3 Qb6b5 Rf1e1 OO Nf3h4 d7d5 e5xd6/ep Ne7f5 Nh4xf5 Qb5xf5 Ra1c1 Rf8d8 Be3c5 Bc8d7 Bc5xb4 Qf5f4 Bb4c3 Rd8e8 Rc1c2 Ra8d8 Re1xe8+ Bd7xe8 Rc2d2 Qf4a4 h2h3 Qa4xd1+ Rd2xd1

Where did you get that opening idea? I only found one game with your position, but 8. Bc4 was played instead. It was at Rilton Cup 2000/2001 with a TC of (40 moves)/(2 h) + (20 moves)/(1 h) + 30 min for the rest of the game, according with this link provided by The Week In Chess 312:

https://old.chesstempo.com/gamedb/game/1807068

[pgn][Event "Rilton Cup 2000/2001"]
[Site "Stockholm (Sweden)"]
[Date "2000.12.30"]
[Round "4"]
[White "Svensson, Bengt"]
[Black "Hector, Jonny"]
[WhiteElo "2393"]
[BlackElo "2499"]
[Opening "Ruy López"]
[Variation "Classical Defence"]
[SubVariation "Charousek Variation"]
[ECO "C64"]
[PlyCount "82"]
[Result "1/2-1/2"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. c3 Bb6 5. d4 exd4
6. cxd4 Nce7 7. O-O c6 8. Bc4 d5 9. exd5 Nxd5 10. Nc3 Ngf6
11. Nxd5 Nxd5 12. Re1+ Be6 13. Ng5 Qd7 14. Nxe6 fxe6 15. Qh5+ g6
16. Qg4 O-O-O 17. Bg5 Rde8 18. Bh4 Rhf8 19. Bg3 Bc7 20. Bxc7 Kxc7
21. Qg3+ Qd6 22. Re5 Rf5 23. Rae1 Rxe5 24. Rxe5 Kd7 25. Qh3 Re7
26. Bxd5 cxd5 27. Qb3 Qc6 28. Re1 b6 29. Qa3 Ke8 30. Qg3 Kd7
31. Qf4 Qd6 32. Qe3 Re8 33. Rc1 Rc8 34. Rxc8 Kxc8 35. h4 Qe7
36. g3 Kd7 37. Kg2 Qf6 38. Qh6 Qf7 39. Qe3 Qf5 40. Qh6 Qe4+
41. Kg1 Qe1+ 1/2-1/2[/pgn]

Where the player with the black pieces performed well in the tournament.

Disclaimer: black Elo was 2499 according to ChessTempo and 2509 according to 365Chess. The 2499 value looks the correct one (2000-October list) instead of 2509 (2000-July list) (FIDE source).

Regards from Spain.

Ajedrecista.

[Guenther]

...
Where did you get that opening idea? I only found one game with your position, but 8. Bc4 was played instead.
...

talkchess ;-)

forum3/viewtopic.php?f=2&t=74000

[Ajedrecista]

Hello Günther:

...
Where did you get that opening idea? I only found one game with your position, but 8. Bc4 was played instead.
...

talkchess

forum3/viewtopic.php?f=2&t=74000

Thank you! Using the search engine of the forum would had saved the question. OTOH, it is incredible that such positions can happen! We are not talking about a KBvK ending, we are talking about a bishop sacrifice for nothing (it must be something indeed) earlier than move 10, still in the opening, with the upper hand to the side with less material. Fantastic!

Regards from Spain.

Ajedrecista.

[Guenther]

Hello Günther:

...
Where did you get that opening idea? I only found one game with your position, but 8. Bc4 was played instead.
...

talkchess ;-)

forum3/viewtopic.php?f=2&t=74000

Thank you! Using the search engine of the forum would had saved the question. OTOH, it is incredible that such positions can happen! We are not talking about a KBvK ending, we are talking about a bishop sacrifice for nothing (it must be something indeed) earlier than move 10, still in the opening, with the upper hand to the side with less material. Fantastic!

Regards from Spain.

Ajedrecista.

Hi Jesus,

Yes that was a wonderful position and new move! Milos though thought it was a blunder which allows drawing?!
A shootout with current strongest programs should reveal more, two years and a NNUE revolution later.

BTW it seems your MPV output (SF15) does not agree with Damirs claim of +1.52 for SF dev at least after the more or less
forced moves you analyzed. (-0.85 9...Nc6)

Best wishes,
Guenther

[Eelco de Groot]

Hello Günther:

...
Where did you get that opening idea? I only found one game with your position, but 8. Bc4 was played instead.
...

talkchess

forum3/viewtopic.php?f=2&t=74000

Thank you! Using the search engine of the forum would had saved the question. OTOH, it is incredible that such positions can happen! We are not talking about a KBvK ending, we are talking about a bishop sacrifice for nothing (it must be something indeed) earlier than move 10, still in the opening, with the upper hand to the side with less material. Fantastic!

Regards from Spain.

Ajedrecista.

My computer analysis conclusion with just two one thread small hashtable engines, one very experimental modification of Rebel only, was that White is, probably, winning hands down after just 10 moves then from the start of the game ( I did not know the game and background, great job guys!) and extending that some 17 full moves after the given by Damir position. Mainly based on what the position and play looks like in the line, Rebel, who was playing the black pieces, gives no more than +1.37 at the end of the line, SF family 2.12, but I think it is -optically at least - won. I posted just a few days ago in Ed's forum

(Maybe Black has just to return the sacrifice somewhere and that could save him, free his Rooks, but that is not so easy to find for a computer, I think humans would do better)

[peter]

Hello Günther:

...
Where did you get that opening idea? I only found one game with your position, but 8. Bc4 was played instead.
...

talkchess

forum3/viewtopic.php?f=2&t=74000

Thank you! Using the search engine of the forum would had saved the question. OTOH, it is incredible that such positions can happen! We are not talking about a KBvK ending, we are talking about a bishop sacrifice for nothing (it must be something indeed) earlier than move 10, still in the opening, with the upper hand to the side with less material. Fantastic!

Hi!
Yes, it's a very good found, yet I had it stored in my database, so I thought, it was already somewhat better known. Checking again I yet see in Hiarcs Tournament-book of latest abo- version still the weaker Bd3 only, which is one of the really rare examples of some kind of little hole in this great book.

As for the winning chances I'd say, maybe Black rather shouldn't take the sac but deny it with 8...d6. yet in the .pgn below I have a single STC- game (afair 30'+5") SF-Dragon with Black losing also, which doesn't mean the position was lost already for sure, so I wouldn't call the move 8.d5 a real distinct winner already, but a game changer it is for sure.

Some games in one .pgn mixed up with the original one from Chess.com, where I think I got the move from for the first time, if my entries in database back from 2020 are correct, evals of the eng-eng-games I did let play out recently included:

[pgn][Event "ECO MegaMatch II! (1|1)"]
[Site "Chess.com"]
[Date "2020.05.20"]
[Round "136"]
[White "Lc0-dev"]
[Black "Stockfish"]
[Result "1-0"]
[ECO "C64"]
[Annotator "2.02;0.44"]
[PlyCount "49"]
[EventDate "2020.??.??"]

{AMD Ryzen 9 5950X 16-Core Processor 3400 MHz W=41.4 plies; 11 890kN/s;
61 953 230 TBAs B=41.2 plies; 11 727kN/s; 46 333 395 TBAs} 1. e4 e5 2. Nf3 Nc6
3. Bb5 Bc5 4. c3 Bb6 5. d4 exd4 6. cxd4 Nce7 7. O-O c6 8. d5 $1 (8. Bd3 $6 {
Hiarcs} d5 9. e5 (9. Nc3 dxe4 10. Nxe4 Nf5 11. Neg5 Nge7 12. Ne5 O-O 13. g4 Nh6
14. Bxh7+ Kh8 15. Bb1 Qxd4 16. Qc2 f5 17. Ngf3 Qd6 18. Nc4 Qg6 19. Nfe5 Qe6 20.
g5 Bc7 21. gxh6 Bxe5 22. Nxe5 Qxe5 23. b3 Qe6 24. Qc3 Rg8 25. Kh1 Qf6 26. Qxf6
gxf6 27. Bc2 Bd7 28. Bb2 Nd5 29. Rae1 Rae8 30. h3 Rg5 31. Rxe8+ Bxe8 32. Kh2
Bd7 33. Rg1 Kh7 34. Bc1 Rxg1 35. Kxg1 Ne7 36. Be3 a6 37. Kh2 Ng8 38. Kg3 Nxh6
39. Bd4 Kg6 40. b4 Nf7 41. h4 Nd6 42. a4 Ne8 43. Bb6 Nd6 {1/2-1/2 (43) Kireev,
S (2339)-Pecotic,K (2124) Lechenicher SchachServer 2007}) 9... Ng6 10. h3 N8e7
$16) 8... cxb5 (8... d6 9. dxc6 bxc6 10. Ba4 {1.23/45} Nf6 {1.19/36 200} 11. e5
{1.25/51 778 (Lg5)} dxe5 {0.71/37 192} 12. Qxd8+ {1.19/51 0} Bxd8 {0.80/39 248}
13. Nxe5 {1.11/49 0} Bb7 {0.77/40 197} 14. Na3 {1.32/52 321 (Sd2)} O-O {
0.69/38 200} 15. Nac4 {1.05/50 30} Ba6 {0.77/39 287 (Lc7)} 16. Bd2 {1.36/44
175 (b3)} Bc7 {0.73/42 558 (c5)} 17. Rfe1 {1.25/49 139} Bb5 {0.81/43 210 (c5)}
18. Bb3 {1.66/50 136} Ng6 {0.75/42 98} 19. Nxg6 {1.58/52 58 (g3)} hxg6 {
0.98/42 191} 20. Ne5 {1.50/51 5} Bxe5 {0.80/43 181} 21. Rxe5 {1.54/51 49} Rfe8
{0.77/42 116} 22. Rxe8+ {1.87/60 357} Rxe8 {1.12/48 553} 23. Re1 {1.44/68 764}
Ra8 {1.25/46 0 (Txe1+)} 24. h4 {2.13/53 123} Nd5 {1.29/46 619} 25. Ba5 {
2.09/54 217} Kf8 {1.37/41 0} 26. Re4 {2.33/56 846 (Td1)} Re8 {1.28/53 1087
(Ld3)} 27. Rd4 {2.10/55 206} Re5 {1.29/54 0 (Te2)} 28. Bd2 {1.93/64 129} Ke7 {
1.32/54 0} 29. f3 {1.83/54 142} Re2 {1.28/52 0} 30. Bd1 {1.83/64 277 (a4)} Re5
{1.08/46 112} 31. Bb3 {1.83/66 0} Re2 {1.32/48 611} 32. a3 {1.94/70 0 (a4)} f6
{1.08/51 206} 33. Bd1 {1.83/65 0} Re5 {1.08/56 79} 34. Bc2 {1.83/60 31} c5 {
1.08/56 256} 35. Re4 {1.82/64 10} Be8 {1.16/44 52} 36. Rxe5+ {1.82/65 49} fxe5
{1.16/54 13} 37. Kf2 {1.82/66 305 (Le4)} Bf7 {1.29/43 157 (Ke6)} 38. g4 {
1.95/55 102 (Le4)} Kd6 {1.17/39 68 (Sf4)} 39. Bb3 {2.05/65 97 (Kg3)} Be6 {
1.24/41 92} 40. Kg3 {2.05/61 45} Nf4 {1.48/48 65} 41. Bd1 {1.93/63 58 (Lc2)} g5
{1.39/43 113} 42. h5 {1.97/61 0} Bd7 {1.56/47 196} 43. Bc2 {1.98/60 0} Bb5 {
1.58/49 188 (Lc6)} 44. b3 {1.93/67 109} Ke6 {1.58/52 0 (Lc6)} 45. Kf2 {2.22/55
284} Bc6 {1.67/54 0 (Kf6)} 46. Be3 {4.23/42 128 (a4)} Kd6 {2.57/34 33} 47. Bf5
{4.96/46 235} a6 {2.92/47 0} 48. Bd2 {5.61/42 125} Kc7 {3.98/36 0 (Se6)} 49.
Be4 {6.64/39 99 (Ke3)} Be8 {4.00/32 34} 50. a4 {7.02/40 49} Nh3+ {5.58/34 8
(Kd6)} 51. Ke3 {7.82/38 124} Nf4 {5.53/40 0} 52. b4 {8.46/43 267} Kd6 {7.02/40
0} 53. bxc5+ {9.00/38 88} Kxc5 {7.42/42 0} 54. a5 {9.07/39 76} Kd6 {7.43/37 0}
55. Bb4+ {9.25/38 129} Ke6 {7.40/41 0} 56. Kd2 {9.62/39 73} Bb5 {6.82/39 0} 57.
Bf8 {9.69/35 67 (Kc2)} Kf6 {7.57/37 36} 58. Bd6 {9.80/38 34} Ne2 {7.36/38 0
(Ke6)} 59. Bd5 {9.74/41 294 (Ke3)} Nf4 {5.11/36 42} 60. Be4 {9.89/38 0 (Lb7)}
Ne2 {7.69/34 27 (Ke6)} 61. Ke3 {10.05/39 168} Ke6 {7.76/40 0} 62. Bc7 {10.44/
37 109 (Lc5)} Nd4 {6.85/33 28} 63. Bb7 {10.50/32 3 (Ld8)} Nb3 {7.06/36 31} 64.
Bc8+ {10.43/33 11} Kf6 {7.38/37 37 (Kd5)} 65. Bd8+ {10.63/36 86 (Lf5)} Kf7 {
6.70/5 0} 66. Ke4 {10.88/33 32 (Lf5)} Nd4 {8.14/33 131 (Sd2+)} 67. Bxg5 {
11.11/28 28 (Lb6)} Nb3 {9.13/28 98 (Se6)} 68. Bd8 {12.58/30 122} Nd2+ {10.50/
33 0} 69. Kxe5 {12.93/22 11} Nxf3+ {10.34/27 13 (Le2)} 70. Kd5 {12.74/25 28
(Ke4)} Kg8 {10.20/28 57 (Le2)} 71. Bc7 {15.17/21 14 (Lb6)} Ne1 {11.16/28 48
(Sd2)} 72. Kc5 {16.19/18 7 (Lb6)} Nd3+ {13.21/25 57 (Sc2)} 73. Kb6 {19.67/19 7}
Nb4 {13.49/25 14} 74. Bb7 {21.29/20 0} Bd7 {14.62/26 69 (Lf1)} 75. Bd6 {
24.87/22 41 (g5)} Nc2 {17.90/24 20 (Sd3)} 76. Bc5 {30.41/20 12 (Lxa6)} Kf7 {
31.25/25 56 (g5)} 77. Bxa6 {151.85/22 13} Be6 {250.00/32 23} 78. g5 {152.55/36
0} Ne1 {250.00/30 32} 79. Bb5 {#18/53 0 (Lb7)} Nf3 {250.00/29 7} 80. a6 {
#17/55 8} Nd2 {250.00/28 0 (Se5)} 81. Bc6 {#11/83 15 (a7)} Nc4+ {#11/25 4} 82.
Kc7 {#10/92 9} Na5 {#9/27 0 (Lg4)} 83. a7 {#8/124 13} Nxc6 {#8/26 0} 84. a8=Q {
#7/177 13} Ne7 {#7/25 1} 85. Bxe7 {#6/245 9 (Dd8)} Bd5 {#6/25 8 (Lg4)} 86.
Qxd5+ {#4/245 1 (Da6)} Kxe7 {250.00/99 0} 87. h6 {1/0 0 (Dd7+)} gxh6 {#3/27 4}
88. g6 {1/0 0 (Dd7+)} Kf6 {#5/23 6} 89. g7 {1/1 0 (Kd7)} Kxg7 {#6/23 7} 90. Qf5
{2/0 0} h5 {#5/24 8} 91. Qxh5 {4/1 0 (Kd7)} Kg8 {#4/66 7} 92. Kd6 {3/1 0} Kg7 {
#3/69 188} 93. Ke6 {2/0 0} Kg8 {#2/65 140} 94. Kf6 {1/1 0} Kf8 {#1/99 0} 95.
Qf7# {#1/0 0 1-0 (95) Stockfish 310722-Dragon 3.1 by Komodo Chess,6 Dort 2022
[1.25;1.19]}) 9. d6 {1.48/46 336} Nc6 (9... h6 {0.75/38 679} 10. e5 {1.73/50 42
} Ng6 {0.86/40 343 (Sc6)} 11. h4 {2.59/42 214 (Sc3)} Nxh4 {0.64/35 201} 12. Nc3
{2.87/43 51} Nxf3+ {1.10/37 259 (Sg6)} 13. Qxf3 {4.40/41 238} h5 {2.39/35 131}
14. Be3 {5.15/39 69 (Df4)} Bxe3 {1.31/42 322} 15. fxe3 {5.54/43 0} Nh6 {
2.08/44 226} 16. Qf4 {5.99/45 146} b6 {4.05/44 559} 17. Nd5 {6.20/51 0} Bb7 {
4.62/38 209} 18. Nc7+ {6.34/47 27} Kf8 {4.94/38 97} 19. e6 {6.60/51 132} Kg8 {
4.74/39 0} 20. e7 {6.62/43 226} Qc8 {4.84/40 0} 21. e8=R+ {6.82/49 426} Qxe8 {
5.32/40 0} 22. Nxe8 {6.89/47 221} Rxe8 {5.19/38 0} 23. Qg5 {6.87/44 156} Kh7 {
5.32/39 250} 24. Qxh5 {6.97/43 0} Be4 {5.42/35 93 (Thf8)} 25. Rac1 {7.14/41
243 (Dxb5)} Re6 {4.83/37 100 (Ld3)} 26. Rc7 {7.49/39 167} Bg6 {5.54/37 198} 27.
Qd1 {7.60/44 295} Rd8 {5.75/36 0} 28. Rxa7 {7.76/43 117} Be4 {5.64/36 194
(Txe3)} 29. Qd4 {7.92/39 162} f5 {6.16/35 0} 30. Qxb6 {8.15/38 188 (Tf4)} Rg6 {
6.33/33 102 adjud. 1-0 Stockfish 310722-Dragon 3.1}) 10. e5 (10. Nc3 $5 h6 11.
e5 {ZU 10...h6 11.Sc3} b4 $15) 10... Kf8 (10... h6 11. a3 {1.79/40}) 11. Nc3
Qe8 12. Re1 h6 13. Nd5 $6 (13. b4 {1.71/40}) 13... Bd8 14. b4 a6 $6 (14... a5 {
1.50/32 0} 15. Nd4 {2.57/42 252} axb4 {0.53/47 279} 16. h3 {2.39/43 33} Nxd4 {
0.68/57 1519} 17. Qxd4 {2.20/61 0} Nf6 {0.68/58 251} 18. Nf4 {2.16/60 76} Kg8 {
0.72/60 573} 19. Bb2 {2.19/60 0} Nh7 {0.72/57 208} 20. Nd5 {2.08/61 340} Qf8 {
0.70/58 0} 21. Qxb4 {2.30/59 423} b6 {0.71/61 0} 22. Ne7+ {2.30/62 647} Bxe7 {
0.67/63 0} 23. dxe7 {2.16/64 1142} Qe8 {0.76/62 233} 24. f4 {2.42/56 0} Bb7 {
0.62/57 157} 25. Qd6 {2.54/47 17 (Ted1)} Nf8 {0.83/49 409 (Lc6)} 26. f5 {
2.75/48 170} Ne6 {0.75/50 0} 27. fxe6 {2.78/51 144} dxe6 {0.77/52 226} 28. Ba3
{2.68/51 1} Bd5 {0.77/54 313} 29. Rf1 {2.68/61 0} Kh7 {1.15/57 1159} 30. Rad1 {
3.99/52 0} Rg8 {1.32/51 850 (Le4)} 31. Rd2 {4.34/68 1888} Be4 {1.38/47 0 (Ta4)}
32. Bb4 {4.88/47 169} Bf5 {1.49/52 381} 33. Qc7 {5.92/45 0 (Dxb6)} Qc8 {
1.63/46 256 (Tc8)} 34. Qxc8 {6.96/42 272} Raxc8 {1.89/44 0} 35. Rf4 {7.16/43
247} Bg6 {2.01/42 179} 36. a3 {7.26/45 5} Rc4 {2.23/43 210} 37. Rf1 {7.38/47 56
} Rcc8 {2.19/40 0} 38. Rfd1 {7.62/48 710} Rce8 {2.30/44 0} 39. Rf2 {7.65/43 97}
Ra8 {2.34/43 0} 40. Rd4 {7.79/43 342} Rge8 {2.34/45 0} 41. g4 {7.81/38 36} Rh8
{2.37/39 39 (Ta4)} 42. Kg2 {7.97/41 60 (Kh2)} Rhe8 {2.57/38 168 (Thg8)} 43. Kg3
{8.29/35 27} Rg8 {2.60/33 5} 44. Rd7 {8.44/42 158 (Tfd2)} Rae8 {2.67/32 24
(Tge8)} 45. Rf4 {8.60/37 31 (Tdd2)} Rc8 {2.71/33 46 (Tb8)} 46. Rd2 {8.52/39 26}
Ra8 {2.62/31 0 (h5)} 47. Kf3 {8.64/38 25} Rae8 {2.62/30 0} 48. Rd7 {8.81/34 5
(Kf2)} h5 {2.78/32 26} 49. Kg3 {8.77/36 0} Rc8 {2.80/30 16} 50. Rf2 {8.91/36 0}
Rce8 {2.77/32 35 (Kh6)} 51. Kh4 {9.20/29 14} Kh6 {2.85/28 0} 52. Bd2+ {9.93/24
14} Kh7 {2.87/31 0} 53. Kg5 {10.19/32 43} b4 {3.10/31 0 (Tc8)} 54. Bxb4 {
10.60/24 13} Rc8 {3.23/30 31 (Ta8)} 55. Rfd2 {11.46/25 19} Rce8 {3.46/26 2} 56.
gxh5 {11.82/24 7} Be4 {3.67/30 46} 57. R7d4 {12.15/28 0} Bf5 {3.84/29 27} 58.
Rd8 {12.93/28 0} Be4 {3.76/29 3} 59. R8d7 {13.38/28 25 (T2d6)} Bc6 {3.75/21 26
(Lb1)} 60. R7d4 {13.67/23 7} f5 {3.85/23 13 (Th8)} 61. exf6 {14.99/22 13} gxf6+
{4.06/22 2} 62. Kxf6 {15.00/23 11} Rg3 {3.87/20 9} 63. R4d3 {17.52/23 8} Rg7 {
3.79/21 19 (Tg1)} 64. Rd8 {19.89/21 15} e5 {5.10/21 18} 65. Kxe5 {21.33/24 0
1-0 EMAN 8.20 64-bit AVX2-ShashChess 23.1}) 15. Be3 h5 16. Bb6 Nxb4 17. Nf6
gxf6 18. exf6 Qxe1+ 19. Qxe1 Bxf6 20. Rd1 (20. Qxb4 Bxa1 21. Ng5 h4 22. Qb3 Nh6
23. Qd1 Bg7 24. Qe2 Bf6 25. Ne4 Ba1 26. Qe1 Bg7 27. Qe3 Ng8 28. Qg5 f6 29. Qg6
Rh6 30. Qf5 Kf7 31. Ng5+ Kf8 32. Nf3 h3 33. g4 Bh8 34. g5 Rh5 35. Be3 b6 36.
Ne5 Rb8 37. Kf1 b4 38. Qg6 fxe5 39. Qxh5 Bb7 40. Qxh8 Bg2+ 41. Ke1 Be4 42. g6
Bxg6 43. Qxh3 Nf6 44. Qh8+ Kf7 45. Qxb8 Nd5 46. Qb7 Ke6 47. Bxb6 Bd3 48. f4
Nxf4 49. Be3 Nd5 50. Kd2 Bc4 51. Qc8 Bb5 52. Qg8+ Kxd6 53. Qg6+ Kc7 54. Ba7 Bc6
55. Qg8 Kd6 56. Qf8+ Ke6 57. Qh6+ Nf6 58. Qh3+ Kf7 59. Qf5 d6 60. Kc1 Ke7 61.
Qc8 Bb5 62. Qc7+ Ke6 63. Bb8 Ne8 64. Qa5 b3 65. axb3 Ke7 66. Bxd6+ Kxd6 67.
Qd2+ Ke6 68. Qh6+ Nf6 69. Qg6 Bc6 70. Qd3 Bb5 71. Qf3 e4 72. Qf4 Be2 73. Kd2
Bg4 74. Ke1 Bh3 75. Qh4 Bf5 76. Qh6 Kf7 77. Qf4 Ke6 78. Qf1 Ke5 79. Qxa6 Nh7
80. Qa5+ Kf6 81. h3 Ke6 82. Ke2 Nf6 83. Ke3 Bg6 84. Qg5 Bh5 85. b4 Bf3 86. b5
Nd7 87. b6 Ne5 88. Qxe5+ Kxe5 89. b7 Ke6 90. h4 Bh5 91. Kxe4 Kd7 92. b8=Q Kc6
93. Ke3 Bg4 94. h5 Bxh5 95. Qe5 Bd1 96. Kd2 Bb3 97. Qc3+ Kd6 98. Qxb3 Kd7 99.
Qf3 Ke6 100. Qc6+ Kf7 101. Kd3 Kg7 102. Ke4 Kh8 103. Qd7 Kg8 104. Ke5 Kf8 105.
Kf6 Kg8 106. Qg7#) 20... Nc6 (20... a5 21. Qe2 Ra6 22. Be3 a4 23. Qxb5 Nc6 24.
Bd2 a3 25. Re1 {2.24/31}) 21. Qe3 b4 22. Ng5 Bc3 23. Qf4 f6 24. Ne4 a5 25. Nxc3
{2.02/33} 1-0
[/pgn]
Edit: had the .pgn changed after some minutes, so better check this one latest version again, if you copied first one at once, regards

[Werewolf]

Komodo Dragon 3.1 does find d5 on my machine, in 5 min 42, depth 40.

On MCTS it doesn't find it within 10 minutes.

[xr_a_y]

Second move for Minic, not far

Code: Select all

info multipv 1 depth 20 score cp 146 time 5363 nodes 4994930 nps 931368 seldepth 33 tbhits 0 pv b5d3 d7d5 b1c3 d5e4 c3e4 c8f5 c1g5 f5e4 d3e4 h7h6 g5h4 g8f6 h4f6 g7f6 d1b3 d8d6 f1e1 a8d8 e1e2 e8g8 a1e1 g8g7 
info multipv 2 depth 20 score cp 105 time 6660 nodes 6192868 nps 929860 seldepth 34 tbhits 0 hashfull 351 pv d4d5 c6b5 d5d6 b5b4 b1d2 e7c6 e4e5 h7h6 f1e1 g7g5 h2h3 e8f8 b2b3 f7f5 d2c4 b6c5 c1b2 b7b5 c4e3 
info multipv 3 depth 20 score cp 68 time 7472 nodes 6972670 nps 933173 seldepth 34 tbhits 0 hashfull 384 pv b5a4 d7d5 b1c3 d5e4 c3e4 e7d5 f1e1 g8e7 a4b3 e8g8 c1g5 h7h6 b3d5 c6d5 g5e7 d8e7 e4c3 e7d6 a1c1 c8e6 

[Eelco de Groot]

Along the line of returning material or Peter's idea of refusing the Bishop:

As for the winning chances I'd say, maybe Black rather shouldn't take the sac but deny it with 8...d6. yet in the .pgn below I have a single STC- game (afair 30'+5") SF-Dragon with Black losing also, which doesn't mean the position was lost already for sure, so I wouldn't call the move 8.d5 a real distinct winner already, but a game changer it is for sure.

This was a bit of a surprise, although Rebel 15.1 does not play 8.d5 itself, not enough compensation, the latest small modification of Rebel (different aspiration windows mainly) does find a way to return the material on move 9. It is a bit of a mystery to me why it now would do that apart from increasing rhe NNUE evals by dividing them only by 90 instead of 100. It, this part of the change in eval probably most behind it, probably means it finds lower scores now for the other moves, and not a very bad idea I think although b4 is a bit of a nullmove you would think. Black does castle in this line, that is already strategically better I have no idea if Rebel now actually sees this better or just search luck.

Of course, White could also refuse the counter sac, then it is totally another game again I suppose. For instance with 10. e5 instead of 10. dxe7

8. d5 cxb5 9.d6

[fen]r1bqk1nr/pp1pnppp/1b1P4/1p6/4P3/5N2/PP3PPP/RNBQ1RK1 b kq -[/fen]

Code: Select all

r1bqk1nr/pp1pnppp/1b1P4/1p6/4P3/5N2/PP3PPP/RNBQ1RK1 b kq -

Engine: Rebel 15.1 MOD-014E (aspiration windowing change, 512 MB)
gemaakt door Fabien Letouzey, Thomas Gaksch, Jerry Donald Watson, Chris whittington en Ed Schröder

15/36  0:01   +0.32--  9...Pg6 10.Pc3 Pf6 11.e5 Pg4 12.Lg5 f6 
                       13.exf6 gxf6 14.Pd4 fxg5 15.Dxg4 O-O 
                       16.Pd5 Kh8 17.Tae1 Pf4 18.Pxb6 Dxb6 
                       19.Te4 Dxd6 20.Dxg5 a6 21.Tfe1 Pg6 
                       22.Te8 Dxd4 (995.434) 760 

15/36  0:02   +0.08    9...b4 10.dxe7 Pxe7 11.Te1 O-O 12.e5 Lc5 
                       13.Pbd2 d5 14.Pb3 Lb6 15.Le3 a5 
                       16.h3 Lxe3 17.Txe3 Le6 (1.564.660) 775 

16/36  0:02   +0.08    9...b4 10.dxe7 Pxe7 11.Te1 O-O 12.e5 Lc5 
                       13.Pbd2 d5 14.Pb3 Lb6 15.Le3 a5 
                       16.h3 Lxe3 17.Txe3 (1.645.197) 776 

17/36  0:02   +0.23    9...b4 10.dxe7 Pxe7 11.Te1 O-O 12.e5 Lc5 
                       13.Pbd2 d5 14.Pb3 b6 15.Le3 Lxe3 
                       16.Txe3 Lg4 17.Pbd4 (1.989.701) 777 

18/38  0:03   +0.26    9...b4 10.dxe7 Pxe7 11.Te1 O-O 12.e5 Lc5 
                       13.Pbd2 d5 14.Pb3 Lb6 15.Le3 a5 
                       16.h3 Lxe3 17.Txe3 h6 18.Pfd4 (2.901.830) 773 

19/38  0:05   +0.30    9...b4 10.dxe7 Pxe7 11.Te1 O-O 12.e5 Lc5 
                       13.Pbd2 d5 14.Pb3 Lb6 15.Le3 a5 
                       16.h3 Lxe3 17.Txe3 Le6 (4.084.470) 780 

20/45  0:14   +0.14++  9...b4 10.dxe7 Pxe7 11.Te1 O-O 12.e5 a5 
                       13.Lf4 Lc5 14.Pbd2 d5 15.exd6 Lxd6 
                       16.Lxd6 Dxd6 17.a3 Lg4 18.Tb1 bxa3 
                       19.bxa3 Dxa3 20.Pc4 Lxf3 21.Dxf3 (11.692.029) 795 

20/45  0:18   +0.46--  9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc7 
                       13.a3 Ta6 14.axb4 axb4 15.Pbd2 Txa1 
                       16.Dxa1 O-O 17.Pc4 h6 18.Td1 Pg6 (14.994.399) 796 

20/45  0:26   +0.31    9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Tfd1 Ke8 
                       22.Pg5 h5 (21.432.754) 798 

21/45  0:27   +0.31    9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Tfd1 Ke8 
                       22.Pg5 h5 (21.797.632) 798 

22/45  0:31   +0.28    9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Te1 Pc6 
                       22.g3 h6 (25.472.128) 799 

23/45  0:38   +0.27    9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Te1 Pc6 
                       22.g3 h6 (31.145.630) 798 

24/45  0:50   +0.28    9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Te1 Pc6 
                       22.g3 h6 (40.359.078) 799 

25/45  1:04   +0.28    9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Te1 Pc6 
                       22.g3 h6 (51.173.569) 799 

26/45  1:19   +0.44--  9...b4 10.dxe7 Pxe7 11.e5 a5 12.Lf4 Lc5 
                       13.Pbd2 d5 14.exd6 Lxd6 15.Lxd6 Dxd6 
                       16.Pc4 Dxd1 17.Taxd1 O-O 18.Pb6 Ta7 
                       19.Pxc8 Txc8 20.Td7 Kf8 21.Tfd1 Ke8 
                       22.Pg5 h6 (63.762.634) 800 

26/49  1:58   +0.60--  9...b4 10.dxe7 Pxe7 11.e5 a5 12.a3 Ta6 
                       13.Lf4 Lc5 14.axb4 Lxb4 15.Pc3 Lxc3 
                       16.bxc3 b5 17.Tb1 Db6 18.Dd3 Dc7 
                       19.Txb5 Lb7 20.Te1 Tg6 21.Kf1 a4 
                       22.Kg1 (95.106.428) 803 

26/50  4:10   +0.54    9...b4 10.dxe7 Pxe7 11.e5 h6 12.Te1 O-O 
                       13.a3 Pf5 14.axb4 d5 15.exd6 Dxd6 
                       16.Dxd6 Pxd6 17.h3 Le6 18.Pc3 Pf5 
                       19.g4 Pe7 20.Le3 Lxe3 21.Txe3 Tfd8 
                       22.b5 a5 (202.655.807) 810 

27/50  4:19   +0.56    9...b4 10.dxe7 Pxe7 11.e5 h6 12.Te1 O-O 
                       13.a3 Pf5 14.axb4 d5 15.exd6 Dxd6 
                       16.Dxd6 Pxd6 17.h3 Le6 18.Pc3 Pf5 
                       19.g4 Pd4 20.Pxd4 Lxd4 21.Le3 Tad8 
                       22.Lxd4 Txd4 (209.613.192) 808 

27/50  5:15   +0.54    9...Pc6 10.Pc3 Df6 11.e5 Dg6 12.Pd5 Ld8 
                       13.Te1 Ph6 14.h4 O-O 15.Lg5 Kh8 
                       16.Lxd8 Txd8 17.Tc1 Pf5 18.Tc5 Tb8 (253.920.171) 803 

28/50  5:49   +0.54    9...Pc6 10.Pc3 Df6 11.e5 Dg6 12.Pd5 Ld8 
                       13.Te1 Ph6 14.h4 O-O 15.Lg5 Kh8 
                       16.Le7 Tg8 17.Dd2 Pf5 18.Lxd8 Pxd8 (280.757.068) 803 

29/50  6:57   +0.59    9...Pc6 10.Pc3 Df6 11.e5 Dg6 12.Pd5 Ld8 
                       13.Te1 Ph6 14.h4 O-O 15.Lg5 Kh8 
                       16.Lxd8 Txd8 17.Tc1 f6 18.Pc7 Tb8 (334.908.174) 803 

29/50  7:38   +0.55    9...b4 10.dxe7 Pxe7 11.e5 h6 12.a3 Pf5 
                       13.axb4 d5 14.exd6 Dxd6 15.Dxd6 Pxd6 
                       16.Pc3 Le6 17.Lf4 Pf5 18.Pa4 Ke7 
                       19.Pxb6 axb6 20.Lc7 Txa1 21.Txa1 Ld5 
                       22.Pe5 b5 (369.123.318) 804 

30/50  9:23   +0.58    9...b4 10.dxe7 Pxe7 11.e5 h6 12.a3 Pf5 
                       13.axb4 d6 14.exd6 Dxd6 15.Dxd6 Pxd6 
                       16.Pc3 Le6 17.Pa4 Ke7 18.Te1 Thd8 
                       19.h3 Kf8 20.Lf4 Pb5 21.Pxb6 axb6 
                       22.Le3 Txa1 (453.292.587) 804 

30/50  10:26  +0.54    9...Pc6 10.Pc3 Df6 11.e5 Dg6 12.Pd5 Ld8 
                       13.Lg5 Lxg5 14.Pxg5 Dxg5 15.f4 Dd8 
                       16.Pc7+ Kf8 17.Pxa8 g6 18.Pc7 Ph6 
                       19.Dd2 Kg7 20.Tac1 a6 21.Tc5 Pf5 (504.761.974) 805 

31/50  14:50  +0.39    9...Pc6 10.Pc3 Df6 11.e5 Dg6 12.Pd5 Ld8 
                       13.Te1 Ph6 14.h4 O-O 15.Lg5 Kh8 
                       16.Le7 Te8 17.Lxd8 Txd8 18.Tc1 Pf5 
                       19.Te4 (709.257.994) 796 

32/56  18:04  +0.55--  9...Pc6 10.Pc3 Df6 11.Pd5 Dxd6 
                       12.Lf4 De6 13.Lc7 Lc5 14.Tc1 d6 
                       15.a3 Dg6 16.b4 Dxe4 17.bxc5 dxc5 
                       18.Txc5 f6 (861.237.554) 794 

32/56  27:01  +0.71--  9...Pc6 10.Pc3 Df6 11.Pd5 Dxd6 
                       12.Lf4 De6 13.Lc7 Lc5 14.Tc1 d6 
                       15.a3 Dg6 16.b4 Dxe4 17.bxc5 Pce7 
                       18.cxd6 Dxd5 19.dxe7 Dxd1 20.Tcxd1 Kxe7 
                       21.Td8 g6 (1.286.620.251) 793 

32/56  32:22  +0.39++  9...b4 10.dxe7 Pxe7 11.e5 O-O 12.a3 Lc5 
                       13.axb4 Lxb4 14.Ld2 Lxd2 15.Dxd2 b5 
                       16.Pd4 d6 17.Pxb5 dxe5 18.Dxd8 Txd8 
                       19.Pc7 Tb8 20.Txa7 Txb2 21.Pc3 Lb7 
                       22.Td1 Txd1+ (1.546.006.988) 796 

31/56  36:37  +0.36    9...b4 10.dxe7 Pxe7 11.e5 O-O 12.a3 Lc5 
                       13.axb4 Lxb4 14.Ld2 Lxd2 15.Dxd2 b5 
                       16.Pc3 Lb7 17.De3 a6 18.Tfe1 Te8 
                       19.Pe4 Lxe4 20.Dxe4 Db6 21.Tad1 Dc6 
                       22.De3 Pg6 (1.753.844.798) 798 

33/59  44:56  +0.43    9...b4 10.dxe7 Pxe7 11.e5 O-O 12.a3 Lc5 
                       13.Pg5 d6 14.Pe4 Pf5 15.exd6 Lxd6 
                       16.Pxd6 Dxd6 17.Dxd6 Pxd6 18.axb4 Pb5 
                       19.Pc3 Pxc3 20.bxc3 a6 21.Td1 Le6 
                       22.Le3 Tfe8 (2.150.704.090) 797 

34/59  52:14  +0.43    9...b4 10.dxe7 Pxe7 11.e5 O-O 12.a3 Lc5 
                       13.Pg5 d6 14.Pe4 Pf5 15.exd6 Lxd6 
                       16.Pxd6 Dxd6 17.Dxd6 Pxd6 18.axb4 Pb5 
                       19.Pc3 Pxc3 20.bxc3 a6 21.Td1 Le6 
                       22.Le3 Tfc8 (2.495.567.780) 796