Is 1. Bg6 Rxe1+ significantly better than 1. Bd3?

[Pafifi]

[d]r1b1r2k/pp1n1pp1/1qpb3p/8/3PB2B/5N2/PPQ2PPP/R3R1K1 w - - 0 1
This is from an EPD who gives the best move Bg6. However, I didn't find it any better than Bd3?

[swissman]

Based on analysis, I conclude that the only difference between the two moves is that with Bg6, White gets slightly better control over the board thus increasing the winning chances.

[Dann Corbit]

I have this analysis for that position:
r1b1r2k/pp1n1pp1/1qpb3p/8/3PB2B/5N2/PPQ2PPP/R3R1K1 w - - ce 155; bm Bd3 Bg6; pm Bd3 Bg6; acd 48; pv Bg6 Rxe1+ Rxe1 Nf8 Bxf7 Bg4 Ne5 Qxd4 Re4 Qd1+ Qxd1 Bxd1 Nc4 Bc5 Na5 b6 Nb7 Bc2 Nxc5 bxc5 Rc4 Bg6 Bxg6 Nxg6 b3 Nxh4 Rxh4 Rb8 Kf1 Rb5 Re4 Kg8 Ke2 Kf7 Kd3 Rb7 Kc3 Rd7 Rc4 Ke6 Rxc5 Kd6 Ra5 Re7 Kd3 g5 Rf5 Ke6 Rf3 Rd7+ Kc3 h5 Re3+ Kd5 Rd3+ Ke6 Rxd7 Kxd7 f3 Kd6 Kc4 a5 a4 g4 f4 Ke6; c0 "Vincent Lejeune - hard CCC 2008 - Pos 48";

r1b1r2k/pp1n1pp1/1qpb3p/8/3PB2B/5N2/PPQ2PPP/R3R1K1 w - - ce 156; bm Bd3 Bg6; pm Bd3 Bg6; acd 47; pv Bd3 Rf8 a3 Qa5 Be7 Bxe7 Rxe7 Kg8 Bh7+ Kh8 Bf5 Qd8 Rae1 Kg8; c0 "Vincent Lejeune - hard CCC 2008 - Pos 48";

[MMarco]

According to CorChess 140520 (with MultiPv=2 & searchmoves e4g6 e4d3), bg6 seems a bit better:

Code: Select all

info depth 46 seldepth 99 multipv 1 score cp 189 nodes 8928181723 nps 2646990 hashfull 1000 tbhits 507935 time 3372956 pv e4g6 e8e1 a1e1 d7f8 g6f7 c8g4 h4g3 g4f3 g3d6 b6d4 d6f8 d4g4 f8g7 h8g7 g2g3 g7f7 c2h7 f7f8 e1e5 f3d5 e5f5 f8e8 f5d5 c6d5 h7h8 e8d7 h8a8 g4b4 a8g8 b4e1 g1g2 e1e4 g2h3 d7c6 g8g4 e4e5 f2f4 e5e4 g4c8 c6b6 f4f5 d5d4 c8e6 e4e6 f5e6 b6c6 h3g4 d4d3 g4f3 c6d6 f3e3 d6e6 e3d3 e6f5 h2h3 f5e5 d3e3 h6h5 a2a4 b7b6 g3g4 h5h4 e3f3 a7a6 b2b4 b6b5 a4a5 e5f6 f3e4 f6g5 e4e5

info depth 46 seldepth 77 multipv 2 score cp 164 nodes 8928181723 nps 2646990 hashfull 1000 tbhits 507935 time 3372956 pv e4d3 e8f8 d3c4 c6c5 h4e7 d6e7 e1e7 b6f6 c2e4 d7b6 c4d3 g7g6 d4c5 b6d5 e7e5 d5f4 d3f1 h8g7 a1e1 f8d8 b2b4 c8e6 g2g3 f4h3 f1h3 e6h3 e4e3 d8d7 e5e4 h3f5 f3e5 d7d5 e5g4 f5g4 e4g4 g6g5 g4c4 a7a6 e3c3 f6c3 c4c3 d5d4 a2a3 d4d7 g1g2 a8c8 e1c1 c8c6 c1c2 f7f5 h2h3 c6e6 c5c6 d7c7 c6b7 c7b7 f2f3 b7d7 a3a4 d7d4 c3c7 g7f6

I aborted the search, but the score for bg6 was actually growing:

Code: Select all

stop
info depth 47 seldepth 97 multipv 1 score cp 217 nodes 13599031330 nps 2660881 hashfull 1000 tbhits 2881223 time 5110725 pv e4g6

[cc2150dx]

Leelenstein 14.3 on my slow gtx 1050

FEN: r1b1r2k/pp1n1pp1/1qpb2Bp/8/3P3B/5N2/PPQ2PPP/R3R1K1 b - - 1 1

Lc0:

16/44 09:16 805k 1k +4.00 Be4-d3 Re8-f8 Bd3-c4 Nd7-f6 Bh4xf6 g7xf6 Ra1-d1 Qb6-c7 h2-h3 Rf8-g8 Kg1-h1 a7-a5 Qc2-e4 a5-a4 d4-d5 Ra8-a5 Bc4-d3 f6-f5 Qe4-d4+ Kh8-h7 d5xc6 Qc7xc6 Bd3-c4 Bd6-c5 Qd4-c3 Bc5-b6 Bc4xf7 Rg8-g7 Qc3xc6 b7xc6 Re1-e8 Rg7xf7 Re8xc8
16/44 09:17 806k 1k +6.70 Be4-g6 Re8xe1+ Ra1xe1 f7xg6 Qc2xg6 Bd6-f8 Qg6-f7 Qb6-b5 Re1-e8 Qb5-d3 h2-h3 Kh8-h7 Nf3-e5 Qd3-d1+ Kg1-h2 Qd1xd4 Ne5xd7 Bf8-d6+ Bh4-g3 Bd6xg3+ Kh2xg3 Qd4-d3+ Kg3-h2 Qd3xd7 Qf7xd7 Bc8xd7 Re8xa8 Bd7xh3 Kh2xh3 Kh7-g6 Ra8xa7
16/44 10:28 948k 2k +6.71 Be4-g6 Re8xe1+ Ra1xe1 f7xg6 Qc2xg6 Bd6-f8 Qg6-f7 Qb6-b5 Re1-e8 Qb5-d3 h2-h3 Kh8-h7 Nf3-e5 Qd3-d1+ Kg1-h2 Qd1xd4 Ne5xd7 Bf8-d6+ Bh4-g3 Bd6xg3+ Kh2xg3 Qd4-d3+ Kg3-h2 Qd3xd7 Qf7xd7 Bc8xd7 Re8xa8 Bd7xh3 Kh2xh3 Kh7-g6 Ra8xa7
17/44 10:29 956k 2k +6.68 Be4-g6 Re8xe1+ Ra1xe1 f7xg6 Qc2xg6 Bd6-f8 Qg6-f7 Qb6-b5 Re1-e8 Qb5-d3 h2-h3 Kh8-h7 Nf3-e5 Qd3-d1+ Kg1-h2 Qd1xd4 Ne5xd7 Bf8-d6+ Bh4-g3 Bd6xg3+ Kh2xg3 Qd4-d3+ Kg3-h2 Qd3xd7 Qf7xd7 Bc8xd7 Re8xa8 Bd7xh3 Kh2xh3 Kh7-g6 Ra8xa7
17/44 10:34 978k 2k +6.68 Be4-g6 Re8xe1+ Ra1xe1 f7xg6 Qc2xg6 Bd6-f8 Qg6-f7 Qb6-b5 Re1-e8 Qb5-d3 h2-h3 Kh8-h7 Nf3-e5 Qd3-d1+ Kg1-h2 Qd1xd4 Ne5xd7 Bf8-d6+ Bh4-g3 Bd6xg3+ Kh2xg3 Qd4-d3+ Kg3-h2 Qd3xd7 Qf7xd7 Bc8xd7 Re8xa8 Bd7xh3 Kh2xh3 Kh7-g6 Ra8xa7
17/44 10:39 987k 2k +6.70 Be4-g6 Re8xe1+ Ra1xe1 f7xg6 Qc2xg6 Bd6-f8 Qg6-f7 Qb6xb2 Bh4-e7 Kh8-h7 Be7xf8 Nd7xf8 Qf7xf8 Qb2-c2 Nf3-h4 Qc2-d2 Nh4-f3 Qd2-c2 h2-h4 Qc2-f5 Qf8-e8 Qf5-g6 h4-h5 Qg6xe8 Re1xe8 b7-b5 Nf3-e5 a7-a5 f2-f4 b5-b4 f4-f5 a5-a4 Ne5-g6 Bc8-b7 Re8-e7
17/44 10:54 1,023k 2k +6.70 Be4-g6 Re8xe1+ Ra1xe1 f7xg6 Qc2xg6 Bd6-f8 Qg6-f7 Qb6xb2 Bh4-e7 Kh8-h7 Be7xf8 Nd7xf8 Qf7xf8 Qb2-c2 Nf3-h4 Qc2-d2 Nh4-f3 Qd2-c2 h2-h4 Qc2-f5 Qf8-e8 Qf5-g6 h4-h5 Qg6xe8 Re1xe8 b7-b5 Nf3-e5 a7-a5 f2-f4 b5-b4 f4-f5 a5-a4 Ne5-g6 Bc8-b7 Re8-e7

[MMarco]

This is Leela output from my phone
Network 702473, MultiPv=4

Code: Select all

[22] 1.24 Fg6 Txe1+ Txe1 fxg6 Dxg6 Cf8 Dxd6 Ff5 b3 Cg6 h3 Da5 Dc5 Dxc5 dxc5 Tf8 Rh2 Cxh4 Cxh4 g5 Cxf5 Txf5 Te8+ Rg7 Te7+ Rg6 f3 a5 Txb7 Txc5 Ta7 h5 h4 gxh4 Ta8 Rh6 Rh3 Rg5 Tg8+ Rh6 a4 Tg5 Tc8 Tg6 Th8+ Rg5 Ta8 Rf4 Txa5 Tg3+ Rh2

[22] 0.69 Dc4 Tf8 Fc2 Db5 Dxb5 cxb5 Fe7 Fxe7 Txe7 Rg8 d5 Td8 Td1 a5 d6 Cc5 Ce5 Fe6 f4 Rf8 Tc7 Tac8 f5 Fxa2 Ta1 Fc4 Txa5 Ca6 Txc8 Txc8 Fe4 Cc5 Ff3 Cd3 Fxb7 Td8 Cc6 Te8 h3 Cc5 Fa8 g6 b4 Cd7 Ta7 gxf5 Txd7 Txa8

[22] 0.68 Fd3 Tf8 Fc4 Cf6 Fxf6 gxf6 Tad1 Fd7 g3 Fg4 Rg2 Da5 d5 Tad8 De4 f5 Dd4+ Rh7 h3 Fxf3+ Rxf3 Dc5 Dd3 Rg7 Dc3+ f6 Dd3 Fe5

[22] 0.58 Ff5 Tf8 a3 Db5 Fd3 Da5 h3 Dc7 Fe7 Fxe7 Txe7 Dd6 Tae1 Cf6 Fc4

d:22/58 t:8236 n:1109k nps:134

[yurikvelo]

Stockfish_20052322 + Syzygy 6-man

After 1. Bg6 eval goes to +2 quite fast, I fed hash to about D=50, then iterate play with D=40...47 per move
Eval stays close to +2 for a long, white has pawn advantage, but with high-mobility Queens on board it takes are while to realize pawn advantage. White mate in 70 moves.

[pgn][Event "Computer chess game"]
[SetUp "1"]
[FEN "r1b1r2k/pp1n1pp1/1qpb3p/8/3PB2B/5N2/PPQ2PPP/R3R1K1 w - - 0 1"]
[PlyCount "139"]

1. Bg6 (1. Bd3 Rf8 2. Bc4 Nf6 3. Bxf6 gxf6 4. Rad1 Qc7 5. d5 Rg8 6. dxc6
Bh3 7. Bf1 Bf8 8. Nd4 Bg4 9. Be2 Bh3 10. Bf3 bxc6 11. Qxc6 Qxc6 12. Nxc6
Be6 13. a3 a5 14. Nd8 Ra6 15. Bd5 Bxd5 16. Rxd5 Ra7 17. h4 a4 18. Re4 Kh7
19. Nc6 Rc7 20. Nb4 Re7 21. Rc4 Bg7 22. Nd3 Ra8 23. Rb4 Raa7 24. Kf1 Rec7
25. g3 Rc2 26. Kg2 Rcc7 27. Kf3 Rc2 28. Ne1 Rc1 29. Ng2 Bf8 30. Rb8 Bg7 31.
Ne3 Rcc7 32. Rdb5 Rc1 33. h5 f5 34. Nxf5 Rc4 35. R8b6 Rd7 36. Rb4 Rdc7 37.
Rb8 Rc2 38. R4b7 Rxb7 39. Rxb7 Kg8 40. Rb4 Kh7 41. Rxa4 Rxb2 42. Ra7 Kg8
43. a4 Ra2 44. a5 Rd2 45. Ra8+ Kh7 46. Ra7 Kg8 47. Ke3 Ra2 48. f4 Ra4 49.
Ra6 Rb4 50. Ra8+ Kh7 51. Ra7 Kg8 52. a6 Rb3+ 53. Ke2 Rb2+ 54. Kd3 Rb3+ 55.
Kc4 Rc3+ 56. Kd5 Ra3 57. g4 Ra1 58. Kc6 Ra4 59. Kb5 Ra1 60. Rc7 Bf6 61. a7
Bd8 62. Rc8 Ra5+ 63. Kb4 Rxa7 64. Rxd8+ Kh7 65. g5 hxg5 66. fxg5 Ra6 67.
Rf8 Ra7 68. Rxf7+ Rxf7 69. g6+ Kg8 70. Nh6+ Kg7 71. gxf7 Kf8 72. Kb5 Ke7
73. Kc5 Kf8 74. Kd6 Kg7 75. Ke6 Kxh6 76. f8=Q+ Kg5 77. Qb4 Kh6 78. Qg4 Kh7
79. Kf7 Kh8 80. Qg8#) 1. .. Rxe1+ 2. Rxe1 Nf8 3. Bxf7 Bg4 4. Bg3 Bxf3 5.
Bxd6 Qxd4 6. Bxf8 Qg4 7. Bxg7+ Kxg7 8. g3 Kxf7 9. Qh7+ Kf8 10. Re5 Bd5 11.
Rf5+ Ke8 12. Rxd5 cxd5 13. Qh8+ Kd7 14. Qxa8 Qb4 15. Qg8 d4 16. Qh7+ Kd8
17. Kg2 Qc4 18. Qh8+ Kc7 19. Qg7+ Kd8 20. Qf6+ Kd7 21. Qf5+ Kc7 22. Qf4+
Kc8 23. h4 Qd5+ 24. Qf3 Qd6 25. Qf5+ Kd8 26. Kf3 Qc6+ 27. Qe4 Qd7 28. Qd3
Qd5+ 29. Kf4 h5 30. Qb3 Qc5 31. Ke4 Qc6+ 32. Kxd4 Qf6+ 33. Ke3 Qe5+ 34. Kf3
Qf5+ 35. Ke2 Qe4+ 36. Kd2 Qc6 37. Qg8+ Ke7 38. Qh7+ Kf8 39. Qh8+ Kf7 40.
Qxh5+ Kg8 41. Qg5+ Kh7 42. Qe5 Qf3 43. Qd4 Qc6 44. Ke3 Kg8 45. Qe5 Kf8 46.
h5 Qb6+ 47. Kf3 Kf7 48. Kg4 a5 49. f4 a4 50. Qf5+ Ke7 51. Qg5+ Kf7 52. Qg6+
Qxg6+ 53. hxg6+ Kxg6 54. f5+ Kh7 55. Kf4 Kg7 56. g4 a3 57. bxa3 b6 58. g5
b5 59. Ke5 Kf7 60. Kd6 Ke8 61. g6 Kf8 62. f6 Ke8 63. Kd5 Kf8 64. Ke6 b4 65.
g7+ Kg8 66. axb4 Kh7 67. Kf7 Kh6 68. g8=Q Kh5 69. Qg3 Kh6 70. Qg6# 1-0[/pgn]



After 1. Bd3 eval is +1.73 @ D=67

D=67, 290 580 MN, 45.7 MTBHits
+1,73 1. ... Rf8 2. Bc4 Nf6 3. Bxf6 gxf6 4. Rad1 Qc7 5. d5 Rg8 6. dxc6 Bh3 7. Bf1 Bf8

iterate play with D=50+ per move lead to white pawn advantage, but with no Queens on board. With less piece mobility eval goes to +2.64 faster then in 1. Bg6
But mate happens later =- on move #80

Under TCEC adjudication rules, 1. Bd3 will be adjudicated faster, eval horizon rise earlier

[Dann Corbit]

I guess bottom line is that both moves win.

[Vinvin]

r1b1r2k/pp1n1pp1/1qpb3p/8/3PB2B/5N2/PPQ2PPP/R3R1K1 w - - 0 1
This is from an EPD who gives the best move Bg6. However, I didn't find it any better than Bd3?

No. Pointed here 9 months ago : http://talkchess.com/forum3/viewtopic.p ... 09#p810909