OliThink - Rybka 50 moves leading...

[OliverBr]

Hi.. I would like to have a analysis of the game between OliThink and Rybka. For almost 50 moves OliThink saw itself in front, had several pawns more and the smell of an upset was in the air... but finally lost.
Now I would like to know, if the game was lost long before, even from the beginning.
Has there been a moment where a stronger engine would have won the game for black?
Perhaps somebody can tell?

Code: Select all

[Event "ICC 4 5"]
[Site "Internet Chess Club"]
[Date "2008.04.05"]
[Round "-"]
[White "Rybka2.3.2"]
[Black "OliPow"]
[Result "1-0"]
[ICCResult "Black checkmated"]
[WhiteElo "2995"]
[BlackElo "2525"]
[Opening "English opening"]
[ECO "A10"]
[NIC "EO.64"]
[Time "00:16:02"]
[TimeControl "240+5"]

1. c4 Nc6 2. g3 e5 3. Bg2 Bc5 4. Nc3 Nf6 5. d3 d6 6. Bg5 Bxf2+ 7. Kd2 Bc5 8.
Bxc6+ bxc6 9. Kc2 h6 10. Bxf6 gxf6 11. Nf3 Be3 12. Qf1 d5 13. Nh4 Rb8 14.
Qf3 Bd4 15. Rhf1 Qd6 16. Rab1 e4 17. dxe4 dxc4 18. Rfd1 Qe5 19. Nf5 Bxf5 20.
exf5 Kf8 21. Qxc6 Bxc3 22. bxc3 Rxb1 23. Kxb1 Qxc3 24. Rd7 Qe1+ 25. Kb2
Qxe2+ 26. Kc3 Qe1+ 27. Kc2 Qf2+ 28. Kc3 Qxf5 29. Qxc7 Qe6 30. Rd8+ Kg7 31.
Rxh8 Kxh8 32. Qxa7 Qe1+ 33. Kxc4 Qe2+ 34. Kb3 Qxh2 35. Qc7 Kg7 36. a4 Qe2
37. a5 Qb5+ 38. Kc3 h5 39. Kd4 Kg6 40. Ke3 Qb4 41. Qc2+ f5 42. Qc6+ Kg5 43.
a6 Qe1+ 44. Kd4 Qxg3 45. Qc1+ Kg6 46. Qc6+ Kg7 47. Qb7 Qh4+ 48. Ke5 f4 49.
a7 f3 50. a8=Q Qf6+ 51. Ke4 f2 52. Qbb8 Qe7+ 53. Kd4 Qh4+ 54. Ke3 f1=N+ 55.
Ke2 Qc4+ 56. Kf2 Qd4+ 57. Kxf1 Qd1+ 58. Kf2 Qd2+ 59. Kg3 Qg5+ 60. Kh3 Qg4+
61. Kh2 Qh4+ 62. Kg2 Qg4+ 63. Qg3 Qg6 64. Qxg6+ Kxg6 65. Qe4+ Kg7 66. Kg3
Kg8 67. Kf4 Kf8 68. Qe5 f6 69. Qc7 h4 70. Kf5 h3 71. Kxf6 Kg8 72. Qg7#
{Black checkmated}
1-0

[swami]

Hi.. I would like to have a analysis of the game between OliThink and Rybka. For almost 50 moves OliThink saw itself in front, had several pawns more and the smell of an upset was in the air... but finally lost.
Now I would like to know, if the game was lost long before, even from the beginning.
Has there been a moment where a stronger engine would have won the game for black?
Perhaps somebody can tell?

Code: Select all

[Event "ICC 4 5"]
[Site "Internet Chess Club"]
[Date "2008.04.05"]
[Round "-"]
[White "Rybka2.3.2"]
[Black "OliPow"]
[Result "1-0"]
[ICCResult "Black checkmated"]
[WhiteElo "2995"]
[BlackElo "2525"]
[Opening "English opening"]
[ECO "A10"]
[NIC "EO.64"]
[Time "00:16:02"]
[TimeControl "240+5"]

1. c4 Nc6 2. g3 e5 3. Bg2 Bc5 4. Nc3 Nf6 5. d3 d6 6. Bg5 Bxf2+ 7. Kd2 Bc5 8.
Bxc6+ bxc6 9. Kc2 h6 10. Bxf6 gxf6 11. Nf3 Be3 12. Qf1 d5 13. Nh4 Rb8 14.
Qf3 Bd4 15. Rhf1 Qd6 16. Rab1 e4 17. dxe4 dxc4 18. Rfd1 Qe5 19. Nf5 Bxf5 20.
exf5 Kf8 21. Qxc6 Bxc3 22. bxc3 Rxb1 23. Kxb1 Qxc3 24. Rd7 Qe1+ 25. Kb2
Qxe2+ 26. Kc3 Qe1+ 27. Kc2 Qf2+ 28. Kc3 Qxf5 29. Qxc7 Qe6 30. Rd8+ Kg7 31.
Rxh8 Kxh8 32. Qxa7 Qe1+ 33. Kxc4 Qe2+ 34. Kb3 Qxh2 35. Qc7 Kg7 36. a4 Qe2
37. a5 Qb5+ 38. Kc3 h5 39. Kd4 Kg6 40. Ke3 Qb4 41. Qc2+ f5 42. Qc6+ Kg5 43.
a6 Qe1+ 44. Kd4 Qxg3 45. Qc1+ Kg6 46. Qc6+ Kg7 47. Qb7 Qh4+ 48. Ke5 f4 49.
a7 f3 50. a8=Q Qf6+ 51. Ke4 f2 52. Qbb8 Qe7+ 53. Kd4 Qh4+ 54. Ke3 f1=N+ 55.
Ke2 Qc4+ 56. Kf2 Qd4+ 57. Kxf1 Qd1+ 58. Kf2 Qd2+ 59. Kg3 Qg5+ 60. Kh3 Qg4+
61. Kh2 Qh4+ 62. Kg2 Qg4+ 63. Qg3 Qg6 64. Qxg6+ Kxg6 65. Qe4+ Kg7 66. Kg3
Kg8 67. Kf4 Kf8 68. Qe5 f6 69. Qc7 h4 70. Kf5 h3 71. Kxf6 Kg8 72. Qg7#
{Black checkmated}
1-0

can't believe that Rybka made the 6.Bg5 blunder, maybe its the book move?

10...Qxf6 is the obvious move even for human, why does it play the 10...gxf6? white's king is in the queen side, no sense in gxf6 with g file open and a doubled pawn. black couldn't castle on king side anymore..

16.Bxc3 better move than e4. e4 just exchanges everything, in the center, where the black king is located in the last center file


49...f3...one big mistake. Qg5+ is better. Oli think avoided every oppurtinity to get the draw. Instead it went on playing till the end. From move 20, the evaluations give 0.00. So i don't see where Oli is bit ahead until the move 50.

[OliverBr]

Hi, thank you very much for this great analysis.

can't believe that Rybka made the 6.Bg5 blunder, maybe its the book move?

It could be a book move, obviously. OliThink didn't play with any book but I don't know about the opponent. Anyway, from your analysis this was the first and the only blunder from Rybka.

10...Qxf6 is the obvious move even for human, why does it play the 10...gxf6? white's king is in the queen side, no sense in gxf6 with g file open and a doubled pawn. black couldn't castle on king side anymore..

Easy to explain. OliThink has just mobility evaluation. gxf6 give the king rook a couple of free squares. the only problem is, as you correctly stated, those squares are not serving anything for a long time. There is no foreign king, it is not a center file and the white g-pawn is blocking the way down.
Something to work about, but still gxf6 is not a real blunder, it's still discussable.

16.Bxc3 better move than e4. e4 just exchanges everything, in the center, where the black king is located in the last center file

Again the "only mobility" evaluation is guilty for this. There is no king-safety implemented in the evaluation (only implicit: when square of next to king are attacked, the king's mobility is bad).

49...f3...one big mistake. Qg5+ is better. Oli think avoided every oppurtinity to get the draw. Instead it went on playing till the end. From move 20, the evaluations give 0.00. So i don't see where Oli is bit ahead until the move 50.

Here we go, this was the big, big blunder. It's horrible move. I have to fix that, thanks!

[OliverBr]

Hi, thank you very much for this great analysis.

49...f3...one big mistake. Qg5+ is better. Oli think avoided every oppurtinity to get the draw. Instead it went on playing till the end. From move 20, the evaluations give 0.00. So i don't see where Oli is bit ahead until the move 50.

Here we go, this was the big, big blunder. It's horrible move. I have to fix that, thanks!

Here we go. It was machine blunder and horizon effect. Until ply 10 OliThink just doesn't see the problem. Then it needs 350.000.000 nodes to find the correct answer: Qf6: draw!

Code: Select all

./olithink -sd 11 "8/PQ3pk1/8/4K2p/5p1q/8/8/8 b - - 0 49"
time 9999999999
go
 1   170      0       114  h4f6 e5e4
 2   141      0       759  h4g5 e5d4 g5d8 b7d5
 3   154      0      3530  h4g5 e5d4 g5g1 d4c4 g1c1 c4d5
 4   124      0     15090  h4f6 e5e4 f4f3 a7a8q f3f2 b7d5
 5    51      2     50299  h4f6 e5e4 f4f3 e4e3 f6c3 e3f2 c3d4 f2f3
 6    99      9    270476  f4f3 b7f3 h4e7 e5f4 e7a7 f3h5 g7f8
 7   116     25    663958  f4f3 b7f3 h4e7 e5f5 e7a7 f3c3 g7h7 f5g5 a7g1 g5h5
 8   136     65   1674307  f4f3 b7f3 h4e7 e5f5 e7a7 f3c3 g7g8 f5g5 a7g1 g5h5 g8f8
 9   116    196   5051451  f4f3 a7a8q h4f6 e5e4 f3f2 b7b8 f6e6 e4d4 e6d7 d4c3 f2f1q b8h8 g7g6 a8g8 g6f5 g8h7 f5g4
10    52    495  12661467  f4f3 a7a8q h4f6 e5e4 f3f2 b7b8 f6e6 e4d4 e6d7 d4c3 f2f1q b8h8 g7g6 a8g8 g6f5 h8h5 f5e6 c3b3
11     0  13086 349123777  h4f6 e5e4 f6g6 e4f4 g6h6 f4f3 h6f6 f3e3 f6e6 e3d3 e6d6 d3e4 d6e6 e4d3
49. ... h4f6

kibitz W: 0 Nodes: 316173002 QNodes: 32950775 Evals: 64621942 cs: 13086 knps: 2667

[George Tsavdaris]

Hi.. I would like to have a analysis of the game between OliThink and Rybka. For almost 50 moves OliThink saw itself in front, had several pawns more and the smell of an upset was in the air... but finally lost.
Now I would like to know, if the game was lost long before, even from the beginning.
Has there been a moment where a stronger engine would have won the game for black?
Perhaps somebody can tell?

9...Ng4 instead of 9...h6 would be an easy win as i see it since:
10.Bxd8 Ne3+ 11.Kd2 Nxd1 12.Rxd1 Kd8 and now black has the Bishop pair against 2 Knight, plus a Pawn more.

10...Qxf6 instead of the bad 10...gxf6? that has been played, would have been much better.

16...Bxc3 instead of 16...e4?! would keep a better positions for black with pressure. After 16...Bxc3 17.Kxc3 Ke7! 18.b3 Rg8 and black is better.

After that last mistake position is about equal although unclear.

And of course as you have said 49...f3? was really bad as 49...Qg5+ would draw easily.


Note that as Swaminathan has said, 6.Bg5?? must be a book move since Rybka could never play such a bad move!

[OliverBr]

Now, times changes and the roles are vice versa now.
OliThink is now playing cat and mouse with Rybka 2.3.2a. Even on windows (not-so-good platform for OliThink) and with black OliThink got (again) the better out of Rybka.

Isn't it amazing?

[pgn][Event "Computer chess game"]
[Site "DESKTOP-1IN7RA6"]
[Date "2021.11.14"]
[Round "?"]
[White "Rybka 2.3.2a 64 bit"]
[Black "OliThink5101"]
[Result "*"]
[BlackElo "2000"]
[ECO "C47"]
[Opening "Four Knights"]
[Time "00:24:18"]
[Variation "Scotch, Bogoljubow, 5.d5"]
[WhiteElo "2000"]
[TimeControl "40/180:40/120:40/120"]
[Termination "normal"]
[PlyCount "109"]
[WhiteType "program"]
[BlackType "program"]

1. Nc3 {(Nb1-c3 Ng8-f6 Ng1-f3 Nb8-c6 d2-d4 d7-d5 Bc1-f4 Nf6-h5 Qd1-d2
Nh5xf4 Qd2xf4 e7-e6) +0.12/14 3} e5 {(e7e5 g1f3 b8c6 d2d4 e5d4 f3d4 f8b4
g2g3 g8e7 f1g2 e8g8 c1f4 d7d6 g2e4 b4c3 b2c3 f7f5 e4c6 b7c6 e1g1 c8d7)
-0.09/21 2} 2. Nf3 {(Ng1-f3 Nb8-c6 g2-g3 d7-d5 d2-d4 e5-e4 Nf3-e5 Ng8-f6
Bc1-f4 Bf8-d6 Bf1-g2) +0.12/14 4} Nc6 {(b8c6 d2d4 e5d4 f3d4 g8f6 a2a3 a7a6
c1f4 d7d5 e2e3 f8d6 f4d6 d8d6 d4c6 b7c6 f1e2 a8b8 a1b1 e8g8 e1g1 f8e8 g1h1
c6c5 b2b3 c7c6 d1d3) -0.15/23 1} 3. e4 {(e2-e4 Ng8-f6 Bf1-b5 Bf8-d6 O-O O-O
d2-d3 a7-a6 Bb5-c4 b7-b5 Bc4-b3) +0.09/14 5} Nf6 {(g8f6 f1b5 a7a6 b5c6 d7c6
d2d3 f8d6 h2h3 c8d7 c1e3 h7h6 e1g1 e8g8 d1e1 d8e7 g1h1 g8h7 a2a3 d6c5 e3c5
e7c5 e1e3) +0.01/23 3} 4. d4 {(d2-d4 e5xd4 Nf3xd4 Bf8-b4 Nd4xc6 b7xc6
Bf1-d3 O-O O-O d7-d5 e4xd5 c6xd5 Bc1-g5 c7-c6) +0.09/15 7} Bb4 {(f8b4 d4d5
b4c3 b2c3 c6e7 f1d3 d7d6 e1g1 e8g8 h2h3 c8d7 a1b1 b7b6 c1g5 e7g6 d3a6 a8b8
g1h2 c7c6 g5f6 d8f6 c3c4) -0.06/22 3} 5. d5 {(d4-d5 Nf6xe4 d5xc6 Ne4xc3
b2xc3 Bb4xc3+ Bc1-d2 Bc3xa1 Qd1xa1 O-O c6xd7 Qd8xd7 Nf3xe5 Rf8-e8) +0.07/14
3} Bxc3+ {(b4c3 b2c3 c6e7 f1d3 d7d6 a2a4 e8g8 e1g1 c8d7 a4a5 a7a6 c3c4 e7g6
c1d2 d8c8 h2h3 h7h6 d2b4 c8b8 c4c5 g8h8 c5d6) -0.17/23 0} 6. bxc3 {(b2xc3)
+0.06/13 0} Ne7 {(c6e7 f1d3 d7d6 a2a4 e8g8 e1g1 c8d7 a4a5 e7g6 c3c4 h7h6
c1d2 d8c8 h2h3 g8h7 d1e2 f8d8 f1b1 a7a6 e2e3 g6f4 c4c5) -0.16/23 2} 7. Bd3
{(Bf1-d3 d7-d6 O-O O-O c3-c4 c7-c5 Bc1-g5 Ne7-g6 h2-h3 h7-h6 Bg5-e3)
+0.39/14 3} d6 {(d7d6 c1g5 c7c6 c3c4 e7g6 a2a4 e8g8 d1b1 c6d5 c4d5 h7h6
g5d2 d8c7 e1g1 c8g4 a4a5 g6f4 d2f4 e5f4 b1b4 g4f3 g2f3 f8c8 f1b1) -0.11/25
6} 8. O-O {(O-O O-O c3-c4 Ne7-g6 Rf1-e1 c7-c5 Bc1-e3 h7-h6 Ra1-b1 Rf8-e8
h2-h3 Qd8-a5) +0.35/15 3} h6 {(h7h6 c1d2 e8g8 h2h3 a7a5 f1e1 c8d7 d1b1 b7b6
a2a4 d8e8 b1b3 e7g6 d3b5 g6f4 b5d7 e8d7 c3c4 g8h7 a1b1 f8b8 g1h2 d7c8)
-0.01/23 3} 9. c4 {(c3-c4 O-O h2-h3 Nf6-d7 Bc1-e3 f7-f5 e4xf5 Ne7xf5 Bd3xf5
Rf8xf5 Qd1-e2 Rf5-f8 Ra1-b1 Nd7-b6) +0.34/14 7} Ng6 {(e7g6 a1b1 e8g8 c1e3
b7b6 h2h3 c8d7 c2c3 a7a5 d3c2 f8e8 g1h1 g8h7 d1d2 f6h5 f1d1 h5f4 a2a3 e8h8
h1h2 h8e8) +0.09/21 3} 10. Be3 {(Bc1-e3 O-O Ra1-b1 b7-b6 Rf1-e1 Bc8-d7
Be3-d2 Qd8-e7 Qd1-e2 Bd7-g4) +0.29/13 3} b6 {(b7b6 a1b1 c8g4 h2h3 g4d7 c2c3
a7a5 d3c2 e8g8 f1e1 g8h7 g1h1 f8g8 a2a3 g8e8 e3d2 e8h8 d2e3 h8f8 h1g1 d8e8
d1d2 f8h8 g1h2 e8c8) +0.07/25 2} 11. Rb1 {(Ra1-b1 O-O Rf1-e1 Bc8-d7 Rb1-b2
Rf8-e8 a2-a3 Qd8-e7 Be3-d2 Bd7-g4 h2-h3) +0.23/14 4} O-O {(e8g8 h2h3 c8d7
g1h2 g8h8 f1e1 f8e8 c2c3 a7a5 a2a3 d8b8 d1d2 d7a4 f3g1 b8d8 g1f3 d8c8 h2g1
h8h7 g1h1) +0.05/23 0} 12. Re1 {(Rf1-e1 Bc8-d7 Be3-d2 Rf8-e8 a2-a3 Ra8-b8
g2-g3 Bd7-h3 Bd2-c3 Nf6-g4) +0.21/13 2} Bd7 {(c8d7 h2h3 a7a5 g1h2 f8e8 c2c3
g8h7 d1d2 d8c8 d2d1 h7g8 a2a3 g8h7 h2h1 c8d8 h1h2 e8h8 h2g1 d8b8 d1d2 b8c8
g1h2) +0.05/23 3} 13. Bd2 {(Be3-d2 Rf8-e8 a2-a3 Ra8-b8 g2-g3 Bd7-h3 Bd2-c3
Qd8-d7 Rb1-b5 Qd7-g4) +0.21/13 3} a5 {(a7a5 h2h3 d8e7 a2a3 f8b8 g1h1 g8h8
d1c1 h8h7 c1d1 e7e8 d2e3 d7a4 e3d2 e8d8 d1c1 a4d7 c1d1 d8h8 d2e3 h8e8 c2c3
e8c8 d3c2) +0.09/24 3} 14. Qe2 {(Qd1-e2 Qd8-e7 g2-g3 Bd7-h3 Kg1-h1 Qe7-e8
Rb1-b5 Bh3-d7 Rb5-b3 Bd7-h3) +0.23/13 3} Nh5 {(f6h5 h2h3 h5f4 e2e3 g8h7
g1h1 d8f6 d2c3 f8b8 h1h2 h7h8 d3f1 f6e7 g2g3 f4h5 e3e2 h5f6 f1g2 b8e8 e2e3
e7d8) +0.14/23 3} 15. g3 {(g2-g3 Bd7-g4 Qe2-d1 Nh5-f6 Kg1-g2 Qd8-d7 a2-a3
Bg4-h3+ Kg2-g1 Nf6-g4 Bd2-c3 Qd7-d8 Qd1-d2 Qd8-f6) +0.21/14 3} Bg4 {(d7g4
e2e3 h5f4 d3f1 f4h3 g1h1 f7f5 f1h3 g4h3 f3g1 h3g4 f2f3 f5f4 e3c3 g4d7 g1e2
f4g3 h2g3 g8h7 a2a3 h7h8 e2g1 h8g8 g1e2 d7h3) +0.23/24 3} 16. Qd1 {(Qe2-d1
Nh5-f6 Kg1-g2 Qd8-d7 a2-a3 Bg4-h3+ Kg2-h1 Bh3-g4 Bd2-c3 Qd7-a4 Rb1-a1
Nf6-h7) +0.11/14 0} Nf6 {(h5f6 g1h1 d8d7 d1e2 d7a4 b1a1 a4a3 h1g2 g4d7 h2h3
f8b8 g2h2 g8h7 e1b1 h7h8 d2c1 a3a4 c1e3 a4a3 e3d2) +0.28/21 3} 17. Kg2
{(Kg1-g2 Qd8-d7 Bd2-c3 Bg4-h3+ Kg2-h1 Qd7-g4 Nf3-d2 Qg4-g5 Re1-g1 Bh3-g4
f2-f3 Bg4-d7) +0.13/14 1} Qd7 {(d8d7 b1a1 g8h7 d1e2 a5a4 g2h1 a4a3 e2e3
d7a4 a1b1 g4d7 e3e2 f8g8 f3g1 g8b8 f2f3 g6e7) +0.38/19 6} 18. Rb5 {(Rb1-b5
Bg4-h3+ Kg2-h1 Bh3-g4 Rb5-b3 Qd7-a4 Bd2-c1 Nf6-d7 Qd1-e2 Nd7-c5 Rb3-a3
Qa4-d7) +0.06/14 5} Kh8 {(g8h8 b5b1 f6h7 h2h4 f7f5 e4f5 g4f5 g2g1 h7f6 f3h2
e5e4 d3f1 f5h3 f2f3 g6e5 f3e4 h3f1) +0.62/18 4} 19. Qe2 {(Qd1-e2 Kh8-g8
Bd2-c3 Bg4-h3+ Kg2-h1 Qd7-g4 Nf3-d2 Qg4-g5 Re1-g1 Rf8-e8 Rb5-b1 Bh3-g4)
+0.14/14 5} Rae8 {(a8e8 d2c3 f6h7 e2e3 f7f5 e4f5 g4f5 f3d2 h7g5 d3f5 d7f5
f2f4 e5f4 e3e8 f8e8 e1e8 h8h7 g3f4) +0.59/21 11} 20. Bc3 {(Bd2-c3 Nf6-h5
Kg2-g1 Nh5-f4 Qe2-e3 Bg4-h3 Re1-b1 Qd7-g4 c4-c5 Nf4-g2 Qe3-e2) +0.07/13 3}
Nxe4 {(f6e4 e2e4 f7f5 f3e5 d6e5 e4e3 f5f4 e3c1 d7f7 d3g6 f7g6 g2g1 f4g3
f2g3 g4h3 c1d2 e5e4 b5b2 e4e3 d2d4 e3e2 b2b1 f8f1 e1f1 e2f1q b1f1) +1.43/22
0} 21. Qxe4 {(Qe2xe4 f7-f5 Nf3xe5 f5xe4 Ne5xd7 Bg4xd7 Bd3xe4 Bd7xb5 c4xb5
Ng6-e5 Re1-f1 Ne5-g4 Be4-d3 Ng4-f6) -0.42/15 4} f5 {(f7f5 f3e5 d6e5 e4e3
f5f4 e3c1 d7f7 d3g6 f7g6 g2g1 e5e4 b5b1 e4e3 c3d4 g4h3 c1b2 h8h7 b2b3 f4g3
h2g3 f8f2 e1e3 e8e3 b3e3 f2c2) +1.81/23 1} 22. Nxe5 {(Nf3xe5 d6xe5 Qe4-e3
f5-f4 Qe3-c1 Ng6-h4+ g3xh4 Bg4-h3+ Kg2-h1 Qd7-g4 Bd3-f1 Bh3xf1 Re1xf1
Qg4-f3+) -1.55/16 11} dxe5 {(d6e5) +2.11/24 4} 23. Qe3 {(Qe4-e3 f5-f4
Qe3-d2 f4xg3 f2xg3 Ng6-h4+ Kg2-h1 Nh4-f3 Qd2-e3 Nf3xe1 Bc3xe1 e5-e4 Bd3-e2
Bg4xe2) -1.83/16 1} f4 {(f5f4 e3c1 d7f7 d3g6 f7g6 d5d6 f4g3 f2g3 g6f7 c1e3
c7d6 b5b6 f7c4 e3d2 g4f3 g2g1 f3c6 c3a5 c4c5 e1e3 f8f3 b6c6 c5c6) +2.17/22
3} 24. Qd2 {(Qe3-d2 f4xg3 f2xg3 Ng6-h4+ Kg2-h1 Nh4-f3 Qd2-e3 Nf3xe1 Bc3xe1
e5-e4 Bd3-e2 Bg4xe2 Qe3xe2 Qd7-f5) -2.03/16 3} fxg3 {(f4g3 f2g3 g6h4 g2h1
h4f3 d2e3 f3e1 c3e1 e5e4 d3e2 g4e2 e3e2 d7h3 h1g1 f8f7 e2g2 h3g4 d5d6 g4d1
g2d2 d1d2 e1d2 e4e3 d2e1 e3e2) +3.57/20 3} 25. fxg3 {(f2xg3 Ng6-h4+ Kg2-h1
Nh4-f3 Qd2-e3 Nf3xe1 Bc3xe1 e5-e4 Bd3-e2 Bg4xe2 Qe3xe2 Qd7-f5 Rb5-b1
Qf5-f3+) -2.03/16 5} Nh4+ {(g6h4 g2h1 h4f3 d2e3 f3e1 c3e1 e5e4 d3e2 g4e2
e3e2 d7h3 h1g1 f8f7 e2g2 h3g4 h2h3 g4d1 g2d2 d1d2 e1d2 e4e3 d2c3 f7f3 c3e1
e3e2 g1h2 f3f1 b5b1 e8e4 c4c5 b6c5 c2c3 e4a4 d5d6 c7d6 b1b8 h8h7) +4.76/25
0} 26. Kh1 {(Kg2-h1 Nh4-f3 Qd2-e3 Nf3xe1 Bc3xe1 e5-e4 Bd3-e2 Bg4xe2 Qe3xe2
Qd7-f5 Rb5-b1 Qf5-f3+ Qe2-g2 Qf3-a3) -2.18/16 0} Nf3 {(h4f3 d2e3 f3e1 c3e1
e5e4 d3e2 g4e2 e3e2 d7h3 h1g1 f8f7 e2g2 h3g4 h2h3 g4d1 g2d2 d1d2 e1d2 e4e3
d2c3 e3e2 b5b1 f7f3 c3e1 f3f1 g1h2 e8e4 c4c5 b6c5 c2c3 e4a4 b1a1 f1f5 c3c4
f5f1 a1c1 a4a2 h3h4 h8h7) +4.94/26 3} 27. Qe3 {(Qd2-e3 Nf3-g5 Bd3-e2
Bg4-f3+ Be2xf3 Rf8xf3 Qe3-e2 Rf3xc3 Rb5-b3 Rc3xb3 c2xb3 e5-e4 Qe2-g2
Kh8-g8) -3.19/16 8} Nxe1 {(f3e1 c3e1 e5e4 d3e2 g4e2 e3e2 d7h3 h1g1 f8f7
e2g2 h3g4 h2h3 g4d1 g2d2 d1d2 e1d2 e4e3 d2e1 e3e2 b5b1 f7f1 g1h2 e8e4 c4c5
b6c5 c2c3 e4a4 g3g4 a4a2 h3h4 c5c4 h2h3 f1f6) +5.06/28 0} 28. Bxe1 {(Bc3xe1
e5-e4 Bd3-e2 Bg4xe2 Qe3xe2 Rf8-f3 Rb5-b3 Re8-f8 Kh1-g1 Qd7-f5 h2-h4 a5-a4
Rb3-c3 Qf5-f6) -2.85/17 5} e4 {(e5e4 d3e2 g4e2 e3e2 d7h3 h1g1 f8f7 e2g2
h3g4 h2h3 g4d1 g2d2 d1d2 e1d2 e4e3 d2c3 e3e2 b5b1 f7f3 c3e1 f3f1 g1h2 e8e4
c4c5 b6c5 c2c3 h8h7 g3g4 e4a4 b1a1 g7g5 a1b1 a4a2 h3h4 g5h4 h2h3 f1f3 h3h4
a2a3) +5.15/29 4} 29. Be2 {(Bd3-e2 Bg4xe2 Qe3xe2 Rf8-f3 Rb5-b3 Re8-f8
Kh1-g1 Qd7-f5 h2-h4 a5-a4 Rb3-c3 Qf5-f6 Rc3xf3 e4xf3) -2.85/17 0} Bxe2
{(g4e2 e3e2 d7h3 h1g1 e4e3 d5d6 f8f7 b5h5 f7f2 e1f2 e3f2 e2f2 h3h5 d6c7
h5e5 c4c5 e5c5 f2c5 b6c5 g1f2 e8c8 f2f3 c8c7 c2c4 c7f7 f3e4 f7f2) +5.77/26
3} 30. Qxe2 {(Qe3xe2 Rf8-f3 Rb5-b3 Re8-f8 Kh1-g1 Qd7-f5 h2-h4 a5-a4 Rb3-c3
Qf5-f6 Rc3xf3 e4xf3 Qe2-f1 Qf6-b2) -3.35/18 2} Qh3 {(d7h3 h1g1 e4e3 d5d6
f8f7 b5h5 f7f2 h5h3 f2e2 g1f1 e2c2 h3h4 c7d6 a2a4 c2a2 h2h3 a2a4 f1e2 a4a2
e2f3 e3e2 f3f2 a2a3 h4f4 a3a1 f4f3 h8h7 f3f5 a1d1 f5f7) +6.04/27 5} 31. Kg1
{(Kh1-g1 e4-e3 d5-d6 c7xd6 Rb5-d5 Re8-e6 Rd5-d4 Re6-f6 Rd4-f4 Rf6xf4 g3xf4
Rf8xf4 Be1-g3 Rf4-d4) -4.72/17 11} e3 {(e4e3 d5d6 f8f7 b5h5 f7f2 h5h3 f2e2
g1f1 e2c2 h3h4 c7d6 a2a4 c2a2 h4d4 a2h2 d4d6 h2a2 d6d4 a2a4 f1e2 a4a2 e2f3
e3e2 d4e4 e8e4 f3e4 a2a1) +6.32/28 7} 32. d6 {(d5-d6 c7xd6 Rb5-b1 Rf8-f7
Qe2-g2 Qh3-g4 c4-c5 e3-e2 h2-h4 Qg4-d4+ Kg1-h2 Qd4xc5 c2-c3 Rf7-f1)
-4.72/17 2} Rf7 {(f8f7 b5h5 f7f2 e1f2 e3f2 e2f2 h3h5 d6c7 h5d1 g1g2 d1d6
c4c5 b6c5 f2f4 d6f4 g3f4 e8c8 g2f3 c8c7 a2a3 c7d7 h2h4 d7d4 h4h5 d4c4 f4f5
c4c2) +6.27/26 2} 33. g4 {(g3-g4 Re8-f8 Rb5-f5 Rf7xf5 g4xf5 c7xd6 f5-f6
Rf8xf6 Be1-g3 Qh3-f5 Qe2-g2 Rf6-f8 h2-h3) -4.83/14 6} Rf2 {(f7f2 e1f2 e3f2
e2f2 h3g4 g1h1 g4d1 h1g2 e8e2 d6c7 e2f2 g2f2 d1c2 f2f3 c2d3 f3g2 d3e4 g2g1
e4g4 g1f2 g4c4 f2g1 c4c1 g1g2 c1c6 g2g1 c6c7 b5b3 c7e5 g1g2 b6b5 g2h3 e5f5
h3g2 g7g6 b3f3 f5c5) +7.63/25 4} 34. Bxf2 {(Be1xf2) -4.05/10 0} exf2+
{(e3f2 e2f2 h3g4 g1h1 g4d1 h1g2 e8e2 d6c7 e2f2 g2f2 d1c2 f2e3 c2c3 e3e2
c3c4 e2d1 c4c7 b5b2 b6b5 b2f2 g7g5 d1e2 c7c4 e2d1 c4d3 f2d2 d3b1 d1e2 b1e4
e2f2 e4f4 f2e1 f4b4 e1d1 h8g7 d1c2 b4c5 c2d1 c5e5 d1c2 h6h5 c2b1 e5f5 d2c2
g7f6) +7.97/23 7} 35. Qxf2 {(Qe2xf2 Qh3xg4+ Kg1-h1 Qg4-d1+ Kh1-g2 Re8-e2
d6xc7 Re2xf2+ Kg2xf2 Qd1xc2+ Kf2-e3 Qc2xc4 h2-h3 Qc4xc7) -4.05/10} Qxg4+
{(h3g4 g1h1 g4d1 h1g2 e8e2 d6c7 e2f2 g2f2 d1c2 f2e1 c2c4 e1d1 c4c7 b5b2
b6b5 b2d2 g7g5 d1e1 c7f4 d2e2 h6h5 e2f2 f4c1 e1e2 g5g4 e2d3 c1c4 d3e3 c4d5
f2f8 h8h7 f8f2) +7.96/26 5} 36. Kh1 {(Kg1-h1 Qg4-d1+ Kh1-g2 Re8-e2 d6xc7
Re2xf2+ Kg2xf2 Qd1xc2+ Kf2-e3 Qc2xc4 h2-h3 Qc4xc7 a2-a4 Qc7-c3+) -4.05/12
0} Qd1+ {(g4d1 h1g2 e8e2 d6c7 e2f2 g2f2 d1c2 f2g1 c2d1 g1f2 d1d4 f2e1 d4c4
e1d1 c4c7 b5b2 b6b5 b2d2 g7g5 d2e2 c7c3 e2d2 h6h5 d2c2 c3e5 d1c1 h8h7 c1b1
e5d4 c2c7 h7g6) +7.93/26 5} 37. Kg2 {(Kh1-g2 Re8-e2 d6xc7 Re2xf2+ Kg2xf2
Qd1xc2+ Kf2-e3 Qc2xc4 h2-h3 Qc4xc7 a2-a4 Qc7-c3+ Ke3-e4 Kh8-g8) -4.05/12 2}
Re2 {(e8e2 d6c7 e2f2 g2f2 d1c2 f2e1 c2c4 e1d1 c4c7 b5b2 b6b5 b2e2 g7g5 d1e1
h6h5 e1f1 c7c4 f1f2 h8h7 e2e7 h7g6 e7e2 g5g4 f2f1 c4f4 e2f2 f4c1 f1g2 c1e3)
+7.99/25 4} 38. dxc7 {(d6xc7 Re2xf2+ Kg2xf2 Qd1xc2+ Kf2-e3 Qc2xc4 Rb5-b2
Qc4xc7 Rb2-f2 Qc7-c5+ Ke3-f3 Kh8-h7 Rf2-e2) -7.35/10 2} Rxf2+ {(e2f2 g2f2
d1c2 f2g1 c2d1 g1f2 d1d2 f2f1 d2f4 f1e1 f4c4 e1d1 c4c7 b5b2 b6b5 b2e2 g7g5
d1e1 h8h7 e1f1 c7c4 f1e1 h6h5 e2f2 h7g6 f2e2 b5b4 e1f2 c4d4 f2g2 d4g4 g2f2
g4f4 f2g1) +8.05/25 4} 39. Kxf2 {(Kg2xf2 Qd1xc2+ Kf2-e3 Qc2xc4 Rb5-b2
Qc4xc7 Rb2-f2 Qc7-c5+ Ke3-f3 Kh8-h7 Rf2-e2) -7.36/11 0} Qxc2+ {(d1c2 f2e1
c2c4 e1d1 c4c7 b5b2 b6b5 b2e2 g7g5 d1e1 h6h5 e1d2 c7c4 d2e3 h8g7 e3f3 c4g4
f3f2 g7g6 f2f1 g4c4 f1f2 c4c5 f2f1 c5c1 e2e1 c1f4 f1g1 b5b4) +8.05/25 8}
40. Ke3 {(Kf2-e3 Qc2xc4 Rb5-b2 Qc4xc7 Rb2-f2 Qc7-c5+ Ke3-f3 Kh8-h7 Rf2-d2
Kh7-g6) -7.36/11 0} Qc3+ {(c2c3 e3e2 c3c4 e2d1 c4c7 b5b2 b6b5 b2c2 c7e5
d1c1 e5a1 c1d2 a1d4 d2c1 g7g6 c1b1 h8g7 a2a3 g7f6 b1a2 f6f5 a2b1 g6g5 b1a2
h6h5 h2h3 d4d5 a2b2 d5e5 b2b1 e5e1 c2c1 e1e6) +8.05/28 9} 41. Ke2 {(Ke3-e2
Qc3xc4+ Ke2-d1 Qc4xc7 Rb5-b2 g7-g5 Rb2-c2 Qc7-f4 Rc2-e2 Kh8-g7 Re2-d2)
-7.36/11} Qxc4+ {(c3c4 e2d1 c4c7 b5b2 b6b5 b2c2 c7e5 c2d2 g7g5 d1c2 h8g7
c2d3 e5d5 d3e3 d5c5 e3d3 c5c4 d3e3 c4f4 e3d3 h6h5 d3c3 f4c4 c3b2 g7f6 b2b1
c4c3 d2e2 c3d3 e2c2 f6e5) +8.05/24 0} 42. Kd1 {(Ke2-d1 Qc4xc7 Rb5-b2 g7-g5
Rb2-c2 Qc7-f4 Rc2-d2 Kh8-g7 Kd1-c2 Kg7-f6) -7.59/12 1} Qxc7 {(c4c7 b5b2
b6b5 b2d2 c7c3 d2d8 h8h7 d8d2 c3a1 d1e2 a1e5 e2f1 g7g5 d2e2 e5f5 f1g1 f5g4
g1f1 g4c4 f1e1 h7g6 e1d1 h6h5 e2d2 c4e4 d1c1 g6f5 c1b2 e4e1 d2c2 e1b4 b2a1)
+8.05/27 0} 43. Rb2 {(Rb5-b2 g7-g5 Rb2-c2 Qc7-f4 Rc2-d2 Kh8-g7 Kd1-c2
Kg7-f6) -7.62/11 0} b5 {(b6b5 b2c2 c7e5 c2d2 e5c3 d2d8 h8h7 d8d2 c3a1 d1e2
a1e5 e2f1 g7g5 d2e2 e5f5 f1g1 f5g4 g1f1 g4c4 f1e1 h7g6 e1f2 h6h5 f2e1 g5g4
e2d2 c4e4 e1d1 e4e3 d1c2 e3c5 c2b1 c5c4) +8.05/27 2} 44. Rc2 {(Rb2-c2
Qc7-d6+ Rc2-d2 Qd6-f4 Rd2-c2 Kh8-h7) -7.55/11 5} Qe5 {(c7e5 c2d2 g7g5 d2d8
h8g7 d8d2 e5c3 d2c2 c3d3 d1c1 d3d4 c1b1 d4b4 b1a1 g7g6 c2c6 g6h5 c6c2 b4d4
a1b1 b5b4 c2c1 h5g6 h2h3 d4d3 b1b2 d3h3 c1c2 h3d3 c2c6 g6h5 b2a1 d3d4 a1b1)
+8.65/24 0} 45. Rd2 {(Rc2-d2 Kh8-h7 Kd1-c2 Kh7-g6 Kc2-d3 b5-b4 Rd2-f2
Qe5-c5 Rf2-e2 Qc5-d5+) -7.76/13 6} g5 {(g7g5 d2c2) +7.56/23 3} 46. Kc2
{(Kd1-c2 Kh8-g7 Kc2-d3 b5-b4 Rd2-c2 g5-g4 Rc2-f2 Qe5-c3+ Kd3-e2 Kg7-g6)
-7.98/12 4} Kg7 {(h8g7 c2d3 e5d6 d3c2 d6c5 c2b1 c5c3 d2c2 c3b4 b1a1 b4d4
a1b1 b5b4 b1c1 h6h5 c1b1 a5a4 c2c1 d4e4 b1a1 e4e5 a1b1 e5h2 c1e1 h2d2 e1e6)
+8.91/20 2} 47. Kb1 {(Kc2-b1 Kg7-g6 Rd2-c2 b5-b4 Rc2-c6+ Kg6-h5 Rc6-c2
g5-g4 Rc2-g2) -8.03/11 1} Qc3 {(e5c3 d2c2 c3b4 b1c1 b4d4 h2h3 d4a1 c1d2
a1e5 c2c3 e5h2 d2d3 h2h3 d3c2 h3g2 c2b1 g2e4 b1c1 e4d4 c3c2 d4f4 c1b2 f4b4
b2c1 b4a3 c1d1 a3f3 c2e2 b5b4 d1e1 h6h5) +9.06/21 2} 48. Rc2 {(Rd2-c2
Qc3-e1+ Kb1-b2 Qe1-e5+ Kb2-b1 b5-b4 Rc2-d2 g5-g4 Rd2-d7+ Kg7-g6 Rd7-d2
Kg6-g5 Rd2-c2 a5-a4) -8.01/12 2} Qb4+ {(c3b4 b1c1 b4d4 h2h3 d4f4 c1b2 f4f6
b2b1 f6f1 b1b2 f1h3 a2a3 h3e6 c2d2 e6e5 b2c2 e5c5 c2b2 h6h5 d2d3 g7f6 d3c3
c5e5 b2c2 e5e2 c2b3 f6f5 c3c5 f5g4 c5c6 e2e4) +9.06/23 0} 49. Kc1 {(Kb1-c1
Qb4-e1+ Kc1-b2 a5-a4) -8.86/14 24} Qd4 {(b4d4 c2c6) +9.07/22} 50. Rc7+
{(Rc2-c7+ Kg7-f6 Rc7-c6+ Kf6-e5 Rc6xh6 Qd4-a1+ Kc1-d2 Qa1xa2+ Kd2-d3
Qa2-c4+ Kd3-d2 b5-b4) -8.46/10 2} Kg6 {(g7g6 c7c6 g6f5 a2a3 d4a1 c1d2 a1a3
d2e2 a3b2 e2f1 b2h2 c6c5 f5g4 c5c8 h2f4 f1e1 f4e4 e1d1 e4d3 d1c1 b5b4 c8c2
a5a4 c1b1) +10.14/18 3} 51. Rc2 {(Rc7-c2 g5-g4 a2-a4 Qd4xa4 Rc2-b2 Qa4-f4+
Kc1-b1 a5-a4 Rb2-c2) -9.55/11 10} b4 {(b5b4 c2c6 g6f5 c6c2 a5a4 h2h3 f5g6
h3h4 g5h4 c2g2 g6f5 g2d2 d4d2 c1d2 h4h3 d2d3 h3h2 d3c4 h2h1q c4b4 h1e4 b4a5
a4a3 a5b5 e4c2 b5a5 c2a2 a5b4 a2a1) +13.16/19 3} 52. h3 {(h2-h3 Qd4-e3+
Kc1-b1 Qe3xh3 Rc2-c6+ Kg6-g7 Rc6-c7+ Kg7-f6 Rc7-c6+ Kf6-e7 Rc6-c7+ Ke7-d6
Rc7-c2) -9.55/11 8} a4 {(a5a4 c2c6 g6h5 c6c8 d4e3 c1d1 e3f3 d1e1 f3e4 e1d1
e4d5 d1c1 d5a2 c8c2 a2a1 c1d2 b4b3 c2c3 b3b2 d2e3 a1e1 e3d4 b2b1q c3c4 b1f5
c4c7 f5h3) +20.40/20 6} 53. Rc6+ {(Rc2-c6+ Kg6-h5 Rc6-c2 Qd4-a1+ Kc1-d2
b4-b3 a2xb3 a4xb3 Rc2-c8 b3-b2 Rc8-b8 b2-b1Q Rb8xb1 Qa1xb1) -14.06/12 5}
Kh5 {(g6h5 c6c2 b4b3 a2b3 a4b3 c2c8 d4a1 c1d2 b3b2 c8b8 a1a5 d2c2 a5c7 c2b2
c7b8 b2a3 b8f4 a3a2 f4a4 a2b1 a4d1 b1b2 d1d3 b2c1 d3c3 c1d1 c3f3 d1d2 f3b3
d2c1 b3a3 c1d1) +M491/21 1} 54. Rc2 {(Rc6-c2 Qd4-a1+ Kc1-d2 b4-b3 a2xb3
a4xb3 Rc2-c8 b3-b2 Rc8-b8 b2-b1Q Rb8xb1 Qa1xb1 Kd2-c3 Qb1-f1) -14.06/12 0}
b3 {(b4b3 a2b3 a4b3 c2c6 b3b2 c1c2 d4a4 c2b2 a4c6 b2b3 c6b5 b3c2 b5c4 c2d1
g5g4 d1d2 g4h3 d2e3 h3h2 e3f3 h2h1q f3e3 h1e4 e3f2) +24.54/18 0} 55. axb3
{(a2xb3 a4xb3 Rc2-c8 Kh5-h4 Rc8-c6 Qd4-g1+ Kc1-b2 Qg1-g2+ Kb2xb3 Qg2xc6
Kb3-b2 Kh4xh3 Kb2-b3) -21.29/12 2 White resigns} *

[/pgn]

Let's have a look at move 19... (black):

[fen]r4r1k/2pq1pp1/1p1p1nnp/pR1Pp3/2P1P1b1/3B1NP1/P1PBQPKP/4R3 b - - 8 19[/fen]

(Question: Why doesn't the fen tag work anymore?)

Stockfish suggests a nice "sacrifice": Nxe4! for black, but OliThink decides for a most strategical gem
...Rae8!!

which forces the white queen back to Qd1, but this is not Rybka's style, so it's
20. Bc3 ... Nxe4!!

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