TCEC Cup 4 Final Game 8 – Stockfish-Leela

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Game Cup 4, Final, Game 8
Result 1-0
ECO B85
Links TCEC archive
Lichess


As this was game 8 in the cup with an even score, a decisive game would determine the cup winner. The book exit was into a complex line of the Sicilian defense, Scheveningen variation, which has seen a number of games at the top GM level. Stockfish (white) managed to create a positional weakness for Leela (black), which ultimately proved to be tactically too difficult for Leela to handle.

Game overview

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Position after 15. g4


1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be2 e6 7. O-O Be7 8. f4 O-O 9. Kh1 Qc7 10. a4 Nc6 11. Be3 Re8 12. Bf3 Rb8 13. Qd2 Bd7 14. Nb3 b6

End of book

15. g4 (diagram)

White begins with an aggressive pawn push, which is a typical plan in this line.


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Position after 31. h6


15... Bc8 16. g5 Nd7 17. Qf2 Bf8 18. h4 Na5(N)

Novelty by the Lichess masters database.[1]

19. Nd2 d5 20. exd5 exd5 21. Rac1 Bb7 22. Nxd5 Qd6 23. Nc3 Qb4 24. Bxb7 Nxb7 25. Nd5 Qxb2 26. Bd4 Qa2 27. c4 Nbc5 28. Qg2 Rbc8 29. h5 Nb3 30. Nxb3 Qxb3 31. h6 (diagram)

With this move, white creates a long-term weakness in black's pawn structure.


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Position after 40. Kg2


31... Rxc4 32. Bxg7 Rce4 33. Nc3 Rc4 34. Rb1 Qa3 35. Nd5 Qc5 36. Bxf8 Kxf8 37. Rbd1 Ree4 38. Qf3 b5 39. axb5 axb5 40. Kg2 (diagram)

This is arguably the critical position of the game. Here, black has to be careful with white's longer-term threats such as Qe7+ and Ra8+ back rank check. But if black can thwart the threats and trade some pieces, a draw should still be obtainable:

  • The most straightforward attempt to draw would be 40... Rcd4 41. Rxd4 Rxd4 42. Nc3. A pair of rooks have been exchanged and the powerful knight has been driven away.
  • Black could also go for counterplay with 40... b4 41. Rfe1 Rxe1 42. Rxe1 b3 with a likely draw.

However, Leela went for a more visually challenging move, x-raying the white king with the queen. But white is not compelled to move the queen on f3, which would expose a potential pin on the knight on d5.


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Position after 50... Kf8


40... Qc6 41. Rfe1

At this point, computer analysis suggests that a line such as 41... Re6 42. Re3 b4 43. Nxb4 Rxb4 44. Qxc6 Rxc6 45. Rxd7 could still be holdable for black by setting up a fortress with king on g8 and a rook on f8. But black exchanged a pair of rooks, which nullifies this fortress possibility.

41... Rxe1 42. Rxe1 Rc1 43. Re3 b4 44. Kh3 Qc4 45.Kg3 Ra1 46. Nc7

Threatens mate with Re8, so the knight sacrifice has to be accepted.

46... Qxc7 47. Qe4

White is threatening with the mate again, and black has to give the knight back to prevent the immediate loss. However, white has a zwischenzug to win a pawn before taking the knight.

47... Ne5 48. Qxb4+ Qe7 49. Qxe7+ Kxe7 50. Rxe5+ Kf8 (diagram)

White now has a winning rook and pawn endgame.

51. Rb5 Ra8 52. f5 Kg8 53. Rb7 Rc8 54. Kf4 Re8 55. Ra7 Rf8 56. Ke5 f6+

With only one pair of rooks on the board, black does not have a fortress and decided to give a pawn, instead. This is because the white king can enter the e7 square, which would not be possible with two pairs of rooks on the board: 56... Kh8 57. Kf6 Kg8 58. Ke7 Rc8 59. Rd7 Rf8 60. Rd8 Rxd8 61. Kxd8 Kf8 62. Kd7 f6 63. g6 hxg6 64. fxg6 f5 65. Ke6 Kg8 66. h7+ Kg7 67. h8=Q+ Kxh8 68. Kf7 f4 69. g7+ Kh7 70. g8=Q+ Kh6 71. Qg6#

57. Ke6 Re8+ 58. Re7 Ra8 59. Kxf6 Rf8+ 60. Ke5 Ra8 61. g6 Ra5+ 62. Kf6 Ra8 63. Rxh7 Ra6+ 64. Kg5 Rxg6+ 1-0.

Game was adjudicated as a tablebase win for white.

Analysis

Jozarov's analysis of the game


Game analysis by ElzChess



References