Cool move!

[rabbits]

Robin: I copied the position into the Fritz9 database which produced 6 games.Four wins for black and two draws.I've copied and pasted the games just in case you don't have access to Fritz 9.
Al

[Event "URU-ch"]
[Site "Montevideo"]
[Date "2001.04.22"]
[Round "2"]
[White "Larrea, Manuel"]
[Black "Izquierdo, Daniel"]
[Result "0-1"]
[ECO "C54"]
[WhiteElo "2191"]
[BlackElo "2288"]
[PlyCount "58"]
[EventDate "2001.04.21"]
[EventType "tourn"]
[EventRounds "9"]
[EventCountry "URU"]
[EventCategory "1"]
[Source "ChessBase"]
[SourceDate "2001.07.03"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. O-O Nf6 5. d3 d6 6. c3 a6 7. Bb3 O-O 8. Nbd2
Ba7 9. Re1 Ng4 10. Re2 Kh8 11. h3 Nh6 12. g4 Nxg4 13. hxg4 Bxg4 14. Qf1 f5 15.
Qg2 Qd7 16. Re1 Rf6 17. Ng5 Raf8 18. exf5 Qxf5 19. Nde4 Rg6 20. d4 Bf3 21. Ng3
Rxg5 22. Bxg5 Qxg5 23. Qh2 exd4 24. Bc2 g6 25. Be4 Ne5 26. Qh3 dxc3 27. bxc3
Bxf2+ 28. Kxf2 Ng4+ 29. Kg1 Qc5+ 0-1

[Event "RUS-Cup2"]
[Site "Moscow"]
[Date "1996.??.??"]
[Round "2"]
[White "Izmukhambetov, Salauat"]
[Black "Aronian, Levon"]
[Result "1/2-1/2"]
[ECO "C54"]
[WhiteElo "2530"]
[BlackElo "2390"]
[PlyCount "118"]
[EventDate "1996.11.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "RUS"]
[Source "ChessBase"]
[SourceDate "2004.01.01"]

1. e4 e5 2. Bc4 Nf6 3. d3 Nc6 4. Nf3 Bc5 5. O-O d6 6. c3 O-O 7. Bb3 a6 8. Nbd2
Ba7 9. Re1 Ng4 10. Re2 Kh8 11. h3 Nh6 12. g4 Nxg4 13. hxg4 Bxg4 14. Nh2 Qh4 15.
Nxg4 Qxg4+ 16. Kf1 f5 17. exf5 Rxf5 18. Ne4 Raf8 19. Ke1 Bxf2+ 20. Kd2 Rf3 21.
Kc2 Qg6 22. Nxf2 Rxf2 23. Be3 R2f3 24. Bd5 Rh3 25. Qg1 Qh5 26. Qg2 Rg3 27. Qxg3
Qxe2+ 28. Bd2 Ne7 29. Re1 Qh5 30. Rh1 Nf5 31. Rxh5 Nxg3 32. Rh3 Nf1 33. Rf3
Rxf3 34. Bxf3 b6 35. Kd1 h6 36. Be1 Ne3+ 37. Ke2 Nf5 38. Bg4 Ne7 39. Bh4 g5 40.
Bf2 Kg7 41. Bh5 Nd5 42. Bf3 Nf4+ 43. Ke3 Kf6 44. Bb7 a5 45. b4 h5 46. bxa5 bxa5
47. c4 h4 48. Be1 a4 49. a3 Ke6 50. Bc6 d5 51. Bxa4 dxc4 52. dxc4 Ng2+ 53. Kf2
Nxe1 54. Kxe1 Kd6 55. Bd1 Kc5 56. Be2 g4 57. Kf2 e4 58. Bf1 g3+ 59. Kg2 Kb6
1/2-1/2


[Event "World ol U16"]
[Site "Kuala Lumpur"]
[Date "2002.08.26"]
[Round "9"]
[White "Palit, Somak"]
[Black "Nasri, Amin"]
[Result "0-1"]
[ECO "C54"]
[WhiteElo "2310"]
[BlackElo "2254"]
[PlyCount "44"]
[EventDate "2002.08.20"]
[EventType "team"]
[EventRounds "10"]
[EventCountry "MAS"]
[Source "ChessBase"]
[SourceDate "2002.09.10"]

1. e4 e5 2. Bc4 Nf6 3. d3 Nc6 4. Nf3 Bc5 5. O-O d6 6. c3 a6 7. Nbd2 O-O 8. Bb3
Ba7 9. Re1 Ng4 10. Re2 Kh8 11. h3 Nh6 12. g4 Nxg4 13. hxg4 Bxg4 14. Qf1 Qd7 15.
Qg2 f5 16. Re1 f4 17. Qh2 Rf6 18. Ng5 h6 19. Ngf3 Bxf3 20. Nxf3 Qg4+ 21. Qg2
Qh5 22. Kf1 Rg6 0-1

[Event "American Continental 2nd"]
[Site "Buenos Aires"]
[Date "2003.08.28"]
[Round "10"]
[White "Crosa, Martin"]
[Black "Sorin, Ariel"]
[Result "0-1"]
[ECO "C54"]
[WhiteElo "2412"]
[BlackElo "2519"]
[PlyCount "72"]
[EventDate "2003.08.17"]
[EventType "swiss"]
[EventRounds "11"]
[EventCountry "ARG"]
[Source "ChessBase"]
[SourceDate "2003.11.11"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. O-O Nf6 5. d3 d6 6. c3 a6 7. Re1 Ba7 8. Bb3
O-O 9. Nbd2 Ng4 10. Re2 Kh8 11. h3 Nh6 12. g4 Ng8 13. Nf1 Be6 14. Ng3 Qd7 15.
Bc2 f6 16. d4 exd4 17. Nxd4 Nxd4 18. cxd4 d5 19. Qd3 g6 20. Be3 Rae8 21. f3 Ne7
22. Kg2 Nc6 23. Rd1 Nb4 24. Qc3 Nxc2 25. Rxc2 c6 26. e5 fxe5 27. dxe5 d4 28.
Bxd4 c5 29. Bxc5 Qxd1 30. Bxa7 Rxf3 31. Qd2 Rd3 32. Qxd1 Rxd1 33. Ne2 Bd5+ 34.
Kg3 Rd3+ 35. Kh2 Bc6 36. Rc3 Rd2 0-1

[Event "FRA-ch (Women)"]
[Site "Aix les Bains"]
[Date "2003.08.22"]
[Round "5"]
[White "Costagliola, Marina"]
[Black "Guichard, Pauline"]
[Result "0-1"]
[ECO "C54"]
[WhiteElo "2240"]
[PlyCount "94"]
[EventDate "2003.08.18"]
[EventType "tourn"]
[EventRounds "11"]
[EventCountry "FRA"]
[Source "ChessBase"]
[SourceDate "2003.09.04"]

1. e4 e5 2. Bc4 Nf6 3. d3 Nc6 4. Nf3 Bc5 5. O-O d6 6. c3 O-O 7. Re1 a6 8. Bb3
Ba7 9. Nbd2 Ng4 10. Re2 Kh8 11. h3 Nh6 12. g4 Ne7 13. Nf1 Ng6 14. N1h2 Ng8 15.
d4 Qe7 16. Bg5 Nf6 17. Bc2 h6 18. Bd2 Bd7 19. Qf1 Bb5 20. Rae1 Rae8 21. b3 Bxe2
22. Qxe2 Qd7 23. d5 c6 24. c4 cxd5 25. cxd5 Rc8 26. Bd3 Rfe8 27. Nf1 Kg8 28.
Kh2 Nf4 29. Bxf4 exf4 30. Qd2 b5 31. Nh4 Bd4 32. Re2 Be5 33. f3 g6 34. Ng2 Rc5
35. Kh1 g5 36. Ne1 Rec8 37. Nc2 h5 38. Rg2 hxg4 39. hxg4 Kg7 40. Nh2 Rh8 41.
Kg1 Rh3 42. Kf1 Qc8 43. Re2 Qh8 44. Rg2 Qh4 45. Kg1 Nd7 46. Kf1 Rc3 47. Be2
Rxh2 0-1

[Event "Sao Paulo CC-ch"]
[Site "Sao Paulo"]
[Date "2005.01.28"]
[Round "9"]
[White "Crosa, Martin"]
[Black "De Souza, Mauro Guimaraes"]
[Result "1/2-1/2"]
[ECO "C54"]
[WhiteElo "2401"]
[BlackElo "2377"]
[PlyCount "195"]
[EventDate "2005.01.22"]
[EventType "tourn"]
[EventRounds "11"]
[EventCountry "BRA"]
[EventCategory "3"]
[Source "ChessBase"]
[SourceDate "2005.03.03"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. O-O Nf6 5. d3 d6 6. c3 O-O 7. Nbd2 a6 8. Bb3
Ba7 9. Re1 Ng4 10. Re2 Kh8 11. h3 Nh6 12. g4 f6 13. Nf1 Nf7 14. d4 Ng5 15. Nxg5
fxg5 16. Be3 Qf6 17. Rd2 Ne7 18. dxe5 Qxe5 19. Bxa7 Rxa7 20. Qe2 Ra8 21. Qe3
Ng6 22. Ng3 Qe7 23. Nf5 Qf6 24. Bd1 Ne5 25. Be2 Bxf5 26. exf5 g6 27. h4 gxf5
28. hxg5 f4 29. gxf6 fxe3 30. fxe3 Rxf6 31. Rf1 Rg6 32. Rd4 Rag8 33. Rff4 h5
34. Kf2 hxg4 35. Rb4 g3+ 36. Kg2 b5 37. Rh4+ Kg7 38. Rbf4 Rb8 39. b3 Rb6 40.
Rh3 Rc6 41. c4 bxc4 42. bxc4 Rb6 43. Rxg3 Rb2 44. Rxg6+ Nxg6 45. Rf2 Rxa2 46.
Kf1 a5 47. Rf5 Ne5 48. c5 Kg6 49. Rf8 dxc5 50. Rc8 c6 51. Rf8 a4 52. Ke1 a3 53.
Ra8 Kf6 54. Ra4 Ke7 55. Kd1 Kd6 56. Ba6 Kd5 57. e4+ Kd6 58. Kc1 Nf3 59. Bc4
Ra1+ 60. Kc2 Nd4+ 61. Kd3 Rh1 62. Kd2 Rh3 63. Ra5 Nb3+ 64. Bxb3 Rxb3 65. Kc2
Rh3 66. e5+ Kxe5 67. Rxc5+ Kd6 68. Ra5 c5 69. Ra8 Kd5 70. Ra7 Kd4 71. Rd7+ Kc4
72. Ra7 Rh2+ 73. Kb1 Kb3 74. Rb7+ Kc3 75. Ra7 Rh1+ 76. Ka2 c4 77. Rxa3+ Kc2 78.
Rg3 Rd1 79. Rf3 c3 80. Rg3 Rd2 81. Rg1 Re2 82. Rh1 Rf2 83. Rg1 Rd2 84. Rh1 Rd1
85. Rh2+ Kd3 86. Rh3+ Kc4 87. Rh4+ Rd4 88. Rh8 Rd1 89. Rh4+ Rd4 90. Rh8 Rd1 91.
Rh4+ Kd3 92. Rh3+ Kc2 93. Rh2+ Rd2 94. Rh1 Kd3+ 95. Kb1 Rb2+ 96. Kc1 Ra2 97.
Rh3+ Kc4 98. Rh8 1/2-1/2

[smirobth]

Robin: I copied the position into the Fritz9 database which produced 6 games.Four wins for black and two draws.I've copied and pasted the games just in case you don't have access to Fritz 9.
Al

Thanks Al,
I have Chessbase and Megabase, and so have those games. What I was hoping for based on Mc Mad's claim that it is an easy win for Black was an annotated game or other analysis to back up the claim. Only one of the megabase games had any analysis, and it did not cover the sac in detail.

[Eelco de Groot]

After 5. Bd5 f4 I had to go forward and back a bit and I did not think Toga would keep the hashresults but this time it did, and now it sees some of Black's attack finally:


1... Nxg4 2. hxg4 Bxg4 3. Qf1 Qd7 4. Qg2 f5 5. Bd5 f4 *

[d]r4r1k/bppq2pp/p1np4/3Bp3/4Ppb1/2PP1N2/PP1NRPQ1/R1B3K1 w - -

Engine: Toga 1.5 Checkov_beta1 bb5men (256 MB, Athlon 2009 MHz, build 3, no operative bitbases yet) by Letouzey, Gaksch, Pudas and de Groot

14/44 0:37 -1.00 2.Qh2 Rf6 3.Kf1 Rh6 4.Qg1 Rf8 5.Ke1 Rff6
6.Qf1 Rfg6 7.a4 Bh3 8.Bxc6 Qxc6
9.Qh1 (23.181.892) 616

15/44 1:38 -1.37 2.Qh2 Rf6 3.Kf1 Rh6 4.Qg1 Rf8 5.Ke1 Rff6
6.Bxc6 bxc6 7.Qg2 Rfg6 8.Ng5 Bxe2
9.Kxe2 d5 10.Kd1 (62.648.795) 634

15/44 2:30 -1.21 2.Re1 Bh3 3.Qh2 Rf6 4.Rb1 Rg6+ 5.Kh1 Bg2+
6.Qxg2 Rxg2 7.Kxg2 Rb8 8.d4 exd4
9.Bxc6 Qxc6 10.cxd4 Re8 11.Rh1 Rf8 (97.146.737) 643

16/51 5:58 -1.95 2.Re1 Bh3 3.Qh2 Rf6 4.Kh1 Rh6 5.Rg1 Qe7
6.Rg5 Bg4 7.Rxg4 Rxh2+ 8.Nxh2 Bxf2
9.Nc4 Bc5 10.d4 exd4 11.Bxf4 dxc3
12.bxc3 (227.909.712) 636

16/51 7:38 -0.99 2.Qh2 Rf6 3.Kf1 Rh6 4.Qg1 Rf8 5.Re1 Rg6
6.Qh1 Ne7 7.Bb3 Rh6 8.Qg1 Bh3+ 9.Ke2 Rg6
10.Ng5 (290.981.658) 634

17/51 16:24 -1.17 2.Qh2 Rf6 3.Kf1 Rh6 4.Qg1 Rf8 5.Ke1 Rff6
6.Qf1 Rfg6 7.d4 exd4 8.Bxc6 bxc6
9.Nxd4 Bxe2 10.Nxe2 Qg4 11.Nc4 Rf6 (621.341.446) 630

17/51 27:16 -0.88 2.Nc4 Rf6 3.Bxc6 bxc6 4.Ncxe5 dxe5
5.Nxe5 f3 6.Nxd7 fxg2 7.Nxf6 Bxe2
8.Nd7 Bxd3 9.Kxg2 Bxe4+ 10.f3 Bf5
11.Ne5 Re8 12.Bf4 Kg8 13.Rd1 h5
14.b3 (1.012.263.311) 618

(Wild West variation there after 6. Nc4 with at least two piece sacrifices, don't know if that's anywhere correct but White is still behind.)

[Eelco de Groot]

Still with the same variation:

r4r1k/bppq2pp/p1np4/3Bp3/4Ppb1/2PP1N2/PP1NRPQ1/R1B3K1 w - -

18/51 48:27 -1.05 2.Nc4 Rf6 3.Bxc6 bxc6 4.Ncxe5 dxe5
5.Nxe5 f3 6.Nxd7 fxg2 7.Nxf6 Bxe2
8.Nd7 Bxd3 9.Kxg2 Bxe4+ 10.f3 Bf5
11.Ne5 Re8 12.Bf4 Kg8 13.Rd1 Bc5
14.b4 (1.797.421.145) 618

[Eelco de Groot]

Still with the same variation:

r4r1k/bppq2pp/p1np4/3Bp3/4Ppb1/2PP1N2/PP1NRPQ1/R1B3K1 w - -

18/51 48:27 -1.05 2.Nc4 Rf6 3.Bxc6 bxc6 4.Ncxe5 dxe5
5.Nxe5 f3 6.Nxd7 fxg2 7.Nxf6 Bxe2
8.Nd7 Bxd3 9.Kxg2 Bxe4+ 10.f3 Bf5
11.Ne5 Re8 12.Bf4 Kg8 13.Rd1 Bc5
14.b4 (1.797.421.145) 618

Maybe it's a draw!

1... Nxg4 2. hxg4 Bxg4 3. Qf1 Qd7 4. Qg2 f5 5. Bd5 f4 6. Nc4 Rf6 *

[d]r6k/bppq2pp/p1np1r2/3Bp3/2N1Ppb1/2PP1N2/PP2RPQ1/R1B3K1 w - -

17/47 8:08 -1.21 3.Bxc6 bxc6 4.Ncxe5 dxe5 5.Nxe5 f3
6.Nxd7 fxg2 7.Nxf6 Bxe2 8.Nd7 Bxd3
9.Kxg2 Bxe4+ 10.f3 Bd5 11.Bf4 Re8
12.Ne5 g5 13.Bg3 Bc5 14.b4 Be3 (301.222.380) 617

18/53 31:02 -1.10 3.Bxc6 bxc6 4.Ncxe5 dxe5 5.Nxe5 f3
6.Nxd7 fxg2 7.Nxf6 Bxe2 8.Nd7 Bxd3
9.Kxg2 Bxe4+ 10.f3 Bd5 11.Ne5 Re8
12.Bf4 g5 13.Bg3 Rb8 14.b3 Bc5
15.Rd1 (1.152.594.805) 618

1... Nxg4 2. hxg4 Bxg4 3. Qf1 Qd7 4. Qg2 f5 5. Bd5 f4 6. Nc4 Rf6 7. Bxc6 bxc6 8. Ncxe5 dxe5 9. Nxe5 f3 10. Nxd7 fxg2 11. Nxf6 Bxe2 *

[d]r6k/b1p3pp/p1p2N2/8/4P3/2PP4/PP2bPp1/R1B3K1 w - -

15/45 1:07 -0.43 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 Re6
14.Nd4 Rh6 15.Bh2 Bc5 16.b4 (44.705.929) 664

16/45 2:04 -0.47 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 a5
14.a4 Re6 15.Nd4 Rh6 16.Bh2 Bc5 (83.254.852) 667

17/45 4:37 -0.53 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 a5
14.a4 Re6 15.Nd4 Rh6 16.Bh2 Bc5
17.e5 Rb6 (187.640.128) 676

18/48 11:45 -0.44 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 a5
14.a4 Re6 15.Nd4 Rh6 16.Bh2 Bc5
17.Rd1 Kf7 (482.727.879) 684

[PauloSoare]

Still with the same variation:

r4r1k/bppq2pp/p1np4/3Bp3/4Ppb1/2PP1N2/PP1NRPQ1/R1B3K1 w - -

18/51 48:27 -1.05 2.Nc4 Rf6 3.Bxc6 bxc6 4.Ncxe5 dxe5
5.Nxe5 f3 6.Nxd7 fxg2 7.Nxf6 Bxe2
8.Nd7 Bxd3 9.Kxg2 Bxe4+ 10.f3 Bf5
11.Ne5 Re8 12.Bf4 Kg8 13.Rd1 Bc5
14.b4 (1.797.421.145) 618

Maybe it's a draw!

1... Nxg4 2. hxg4 Bxg4 3. Qf1 Qd7 4. Qg2 f5 5. Bd5 f4 6. Nc4 Rf6 *

[d]r6k/bppq2pp/p1np1r2/3Bp3/2N1Ppb1/2PP1N2/PP2RPQ1/R1B3K1 w - -

17/47 8:08 -1.21 3.Bxc6 bxc6 4.Ncxe5 dxe5 5.Nxe5 f3
6.Nxd7 fxg2 7.Nxf6 Bxe2 8.Nd7 Bxd3
9.Kxg2 Bxe4+ 10.f3 Bd5 11.Bf4 Re8
12.Ne5 g5 13.Bg3 Bc5 14.b4 Be3 (301.222.380) 617

18/53 31:02 -1.10 3.Bxc6 bxc6 4.Ncxe5 dxe5 5.Nxe5 f3
6.Nxd7 fxg2 7.Nxf6 Bxe2 8.Nd7 Bxd3
9.Kxg2 Bxe4+ 10.f3 Bd5 11.Ne5 Re8
12.Bf4 g5 13.Bg3 Rb8 14.b3 Bc5
15.Rd1 (1.152.594.805) 618

1... Nxg4 2. hxg4 Bxg4 3. Qf1 Qd7 4. Qg2 f5 5. Bd5 f4 6. Nc4 Rf6 7. Bxc6 bxc6 8. Ncxe5 dxe5 9. Nxe5 f3 10. Nxd7 fxg2 11. Nxf6 Bxe2 *

[d]r6k/b1p3pp/p1p2N2/8/4P3/2PP4/PP2bPp1/R1B3K1 w - -

15/45 1:07 -0.43 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 Re6
14.Nd4 Rh6 15.Bh2 Bc5 16.b4 (44.705.929) 664

16/45 2:04 -0.47 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 a5
14.a4 Re6 15.Nd4 Rh6 16.Bh2 Bc5 (83.254.852) 667

17/45 4:37 -0.53 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 a5
14.a4 Re6 15.Nd4 Rh6 16.Bh2 Bc5
17.e5 Rb6 (187.640.128) 676

18/48 11:45 -0.44 8.Nd7 Bxd3 9.Bf4 Re8 10.Ne5 Bf1
11.Bg3 Kg8 12.Re1 Bb6 13.Nxc6 a5
14.a4 Re6 15.Nd4 Rh6 16.Bh2 Bc5
17.Rd1 Kf7 (482.727.879) 684

Eelco, after 6...Nc4, 7. Rae8 it´s a strong move,
and I think that black wins.
A good test position for engines.

Paulo Soares

[Eelco de Groot]

Hi Paulo,

Yes, I think thay you are right and Toga Checkov beta missed that one. It is not so easy to find, although the idea is clear, to cover pawn e5 three times. I see no defence for White. Well done!

There must be a way for Toga to find that move also! I'm doing three checks in QSearch, and that is really a lot but often it does not help yet, like here I can't see exactly what is happening when Toga does not find such things.. I wish I had some idea where to look

Regards, Eelco

6.Nc4 Rae8 *

[d]4rr1k/bppq2pp/p1np4/3Bp3/2N1Ppb1/2PP1N2/PP2RPQ1/R1B3K1 w - -

Engine: Toga 1.5 Checkov_beta1 bb5men (256 MB)
by Letouzey, Gaksch, Pudas and de Groot

11/34 0:03 -1.08 3.Re1 Nd8 4.Ncd2 Rf6 5.Nh4 Rh6 6.Nf5 Bh3
7.Qf3 Rg6+ 8.Kh1 Bxf5 9.exf5 Qxf5 (1.993.034) 503

11/34 0:05 -0.82 3.Bxc6 bxc6 4.Re1 Bh3 5.Qg5 Rf6
6.Nh4 h6 7.Qh5 Bg4 8.Ng6+ Kh7
9.Ngxe5 dxe5 10.Nxe5 (2.881.209) 520

11/36 0:13 -0.52 3.Rd2 Nd8 4.Na5 Rf6 5.Nh4 b6 6.Nb3 f3
7.Qh2 c6 8.Bc4 (7.152.634) 528

12/36 0:15 -1.53 3.Rd2 Nd8 4.Na5 b6 5.Nc6 Bxf3 6.Nxe5 dxe5
7.Qxf3 c6 8.Bb3 b5 9.a4 Bc5 10.axb5 axb5 (8.416.157) 533

12/40 0:20 -0.78 3.Re1 Nd8 4.Ncd2 Rf6 5.Nh4 Rh6 6.Nf5 Bh3
7.Qf3 Rg6+ 8.Kh2 Bxf5 9.exf5 Qxf5
10.Qh3 (10.954.151) 543

13/40 0:32 -0.85 3.Re1 Nd8 4.Ncd2 Bh3 5.Qh2 Rf6 6.d4 Rg6+
7.Kh1 Bg2+ 8.Qxg2 Rxg2 9.Kxg2 Qg4+
10.Kh1 h5 11.Kh2 exd4 12.cxd4 (17.984.893) 560

14/40 1:07 -0.99 3.Re1 Nd8 4.Ncd2 Bh3 5.Qh2 Rf6 6.Kh1 Rh6
7.Rg1 Bf1 8.Rxf1 Rxh2+ 9.Kxh2 c6
10.Bb3 Bc5 11.d4 (39.028.432) 579

15/44 3:01 -0.94 3.Re1 Nd8 4.Ncd2 Bh3 5.Qh2 Rf6 6.Kh1 Rh6
7.Rg1 Bf1 8.Rxf1 Rxh2+ 9.Kxh2 c6
10.Bb3 Qg4 11.d4 Qh5+ 12.Kg2 (108.115.762) 594

16/48 6:44 -1.95 3.Re1 Nd8 4.Ncd2 Bh3 5.Qh2 Rf6 6.Kh1 Rh6
7.Rg1 Qe7 8.Rg5 Bg4 9.Rxg4 Rxh2+
10.Kxh2 Bxf2 11.Rg2 Be3 12.Kh1 (240.608.670) 594

16/51 9:14 -1.91 3.Rd2 Nd8 4.Na5 b6 5.Nb7 Bxf3 6.Qxf3 c6
7.Nxd6 Qxd6 8.Bb3 Ne6 9.Kf1 b5 10.a4 Nc5
11.Bc2 bxa4 12.Bxa4 Nxa4 13.Rxa4 (327.197.874) 590

17/54 29:02 -1.81 3.Rd2 Nd8 4.Nh4 c6 5.Nxd6 Bh3 6.Qf3 Qxd6
7.Bxc6 Nxc6 8.Qxh3 Qh6 9.Kh2 Qg5
10.b3 Bc5 11.b4 Bb6 12.Nf5 (1.011.458.784) 580

best move: Re2-d2 time: 40:15.047 min n/s: 587.214 CPU 100.0% n/s(1CPU): 587.214 nodes: 1.418.140.000

[Jack Lad]

Nxg4 is not an immediate win but puts white in severe trouble in where exact move choice may be needed to survive, and I hadn't get too broad/deep to know that black doesn't win for sure.

I'll continue analyzing it when I have the time.

I think that Nxg4! does win but it is by no means an easy win for black.

[Terry McCracken]

Nxg4 is not an immediate win but puts white in severe trouble in where exact move choice may be needed to survive, and I hadn't get too broad/deep to know that black doesn't win for sure.

I'll continue analyzing it when I have the time.

I think that Nxg4! does win but it is by no means an easy win for black.

With Perfect Play it probably wins. But who plays perfectly?

Anyway, 12..Nxg4 is a book move and Rybka never found it on its own.

I wouldn't call it an immortal game for several reasons, one Nxg4 is book and White followed an inferior line, two it's not an easily forced win if it is a forced win, three White made more errors out of book, (bad ones), four any good engine can find those so-called wonderful sacs for Black after White played so badly.

Regardless, Nxg4 is probably Black's best move and that is why it made it into book.

It is a very interesting move, thematic to a point but in this case I'd call it a True Sacrifice as it doesn't lead to an immediate forced win of material, only to potential tactics in a long battle.

Unfortunately this move was played by Rybka only due to it being a book move, otherwise I'd tip my hat.

Hat's off to the one who first found 12..Ng4!

[Ovyron]

Unfortunately this move was played by Rybka only due to it being a book move, otherwise I'd tip my hat.

Chess Tiger plays it under 7 seconds so I wonder if it was used by the book maker.