TCEC Season 17 CPU League 1 Game 138 – Komodo MCTS-Ethereal
|Game||Season 17, CPU League 1, Game 138|
|Links|| TCEC archive|
This game was the second encounter of Komodo MCTS and Ethereal with the same opening. The previous game with colors reversed was TCEC Season 17 CPU League 1 Game 18 – Ethereal-Komodo MCTS.
|Position after 10. Ne1|
1. d4 a6 2. e4 e6 3. Nf3 d5 4. Nbd2 Bd7 5. Bd3 Bb5 6. Bxb5+ axb5 7. O-O Nf6 8. Qe2 c6
End of opening book moves. No games in the Lichess masters database.
9. e5 Nfd7 10. Ne1 (diagram)
The game is in a juncture with many different options for both sides. Here are some options for black:
- 10... b4. Prepares for the c5 push by moving the b-pawn from the harms way. Then, for example, 11. Nd3 Be7 12. Qg4 g6. The last move weakens black's kingside dark squares, but also stops the immediate threats and discourages a future f5 by white. Black should now have time for slower b6 and c5 to obtain good pawn structure on the queenside. 12... Kf8 was also an interesting option here, giving up the castling rights but maintaining no weaknesses on the king side.
- 10... Be7 11. Nd3 b4 12. Nb3 Na6 13. f4 O-O was the line played in the reverse game. It should be noted that 10... b4 and 10... Be7 are interchangeable by move ordering.
- 10... Na6 11. Qg4 c5 12. c3 b4 attacking white's center
- 10... c5 11. dxc5 Bxc5 12. Qxb5 to accelerate piece development.
White also has choices to make, such as whether to focus on the kingside or the queenside. In this game, white went for the queenside pressure, whereas in the reverse, kingside attack was the main plan.
In the game, black went with a perhaps slightly dubious choice, attacking the center but at the cost of a healthy queenside pawn structure.
(Editors note. Analysis with SF11 to depth 43 and 48.7G nodes: 10... b4 0.00; 10... Be7 0.00; 10... Na6 +0.23; 10... Qc7 +0.25; 10... c5 +0.49. Leela T42810 top moves after 10M nodes: 10... b4 +0.34; 10... Be7 +0.36; 10... Qc7 +0.36; 10... Na6 +0.39; 10... c5 +0.46)
|Position after 18. g3|
10... Qc7 11. Nb3 c5 12. dxc5 Bxc5 13. Qxb5 Ba7 14. Kh1 Qc4
A creative way to block the white queen, essentially forcing a queen trade. If the white queen moves away from the a6-f1 diagonal, the rook on f1 is hanging.
The immediate problem for black is that the queenside is tangled. The quick solution does not work, as 15... Qxb5? 16. axb5 and the bishop is threatened to get pinned. The continuations are very favorable for white. For example: 16... Nb6 17. Be3 N8d7 18. Nd3 Ke7 19. Bd4 Rhc8 20. Nbc5 Nc4 21. Rxa7 Rxa7 22. Nxd7 Ra5 23. N7c5 Rxb5 leaving white with 2 pieces for a rook and strong pressure on the Q-side.
However, black does not have to take the queen. Instead, black can develop with natural moves such as Nc6 and O-O to connect the rooks and to then allow Qxb5 with better terms.
White does not wait for black's development.
16. Qxc4 dxc4 17. Nd2 Nxe5 18. g3 (diagram)
In the game, black pushed the c-pawn a move later. However, if that was the plan, pushing the c-pawn right away was also an option: 18... c3 19. Ne4 h5 20. b3 O-O. The difference is that now black gets to blockade white's queenside pawn front with the advanced c3-pawn. Taking with 19. bxc3 was not really an option for white, as it would ruin the queenside pawns.
However, here an arguably stronger move was 18... Bc5 unblocking the b-pawn. If white would now continue with the f-pawn push, then 19. f4 Ned7 20. Nxc4 b5 winning the a-pawn on the next move. This would have resulted in a more balanced position.
|Position after 26. Rxf3|
18... O-O 19. f4 c3 20. fxe5
Note that 20. bxc3 Ned7 21. Nd3 Rc8 would leave the doubled c-pawns weak, so it was not a good option.
20... cxd2 21. Bxd2 Nc6 22. Nf3 Rfd8 23. b4 Bd4 24. Ra2 Nxe5 25. c3 Nxf3 26. Rxf3 (diagram) Bf6
The last move was undoubtedly an inaccuracy. Black needs the bishop to slow down white's pawn front, and better squares for that purpose were a7 and e5. To illustrate: 26... Be5 27. a5 Rac8. Now, unlike in the game, 28. Rc2 can be met with 28... Rc4.
The idea behind 27... Ba7 would be somewhat different, supporting the e-pawn push for active counter-pawn.
|Position after 45. c5|
Now that the is bishop on f6, white has an answer the rook blockading idea: 27... Rac8 28. Rc2 Rc4. Now 29. Rf4 can be played, as the bishop is not controlling the f4-square. Thus, black did not go for it.
27... Kf8 28. Rc2 Ke8 29. Kg2 Ke7 30. Kf2 Rac8 31. c4 Rd5 32. Ke2
The rook was of course not hanging: 32. cxd5? Rxc2 33. Rd3 e5.
32... Re5+ 33. Be3 h6 34. Kf1 Re4 35. Bc5+ Ke8 36. Re3 Rg4
It is in black's best interest to keep the rooks, as more pieces offer generally better chances for counterplay. However, the rook is getting short of squares.
37. h3 Rg5 38. Rb3 Re5 39. Bf2 Ra8 40. Re2 Rf5 41. Rd3 h5 42. Rd6 Bd8 43. Kg2 Bc7 44. Rd3 g6 45. c5 (diagram) Re5
Now black offers the rook exchange. White's threat was to double on the d-file: 45... g5 46. Red2 g4 47. hxg4 hxg4 48. Rd7
|Position after 52. Ra1|
46. Rxe5 Bxe5 47. Kf3 Bc7 48. Be1 e5 49. b5 f5 50. Ke2 e4 51. Rd1 Bxa5
Black didn't have anything better to stop the pawns, but now white gets to pin and win the bishop. For example: 51... Ke7 52. a6 bxa6 53. b6 Be5 54. b7 Rd8 55. Bc3 Bc7 56. Bf6+ Kxf6 57. Rxd8 Ke7 58. Rd1 Bxg3 with no hope for black of stopping the advanced b/c pawns.
52. Ra1 (diagram) Rc8 53. Rxa5 Rxc5 54. h4
Conversion here still needs care, as black has counterplay options. If white was to play the tempting bishop move to prevent b6 driving the rook away, the natural plan would fail: 54. Bf2 Rc2+ 55. Ke1 h4 56. gxh4 f4 57. Ra7?? e3. White has to give up the bishop to stop the pawns, and the game is a draw.
|Position after 66. Kg1|
54... Kd7 55. Ke3
As keeping the b-pawn with advantage is not so easy, white goes for a more straightforward solution and offers the b-pawn for the rook's access to the kingside pawns.
55... b6 56. Ra7+ Ke6 57. Kf4 Rxb5 58. Rg7 g5+ 59. Rxg5 Rb1 60. Bd2 Rf1+ 61. Ke3 Ra1 62. Ke2 Ra3 63. Be3 Ra2+ 64. Kf1 Ra1+ 65. Kf2 Ra2+ 66. Kg1 (diagram) Ra3
Black gives up the b6 pawn without a fight, which is a sign of an engine fighting in a losing position.
Regardless of the b5-pawn black was losing anyways. For example: 66... b5 67. Rxh5 b4 68. Rh6+ Kd5 69. Rb6 Kc4 70. h5 Kd3 71. Bc5 e3 72. Rxb4 Ra1+ 73. Kg2 e2 74. Bf2 e1=Q 75. Bxe1 Rxe1 76. Rf4. A rook and two connected passed pawns against a rook is an easy win for white.
|Position after 77... e2|
67. Bxb6 Rc3 68. Ba5 Rf3 69. Be1 Ra3 70. Kf1 Ra2 71. Rxh5 Rh2 72. Bf2 Rh1+ 73. Kg2 Rb1 74. g4 f4
Final try for black to make some active counterplay with the connected passers. But as the white king and bishop are in the vicinity of the pawns, white is well prepared to sacrifice the bishop for both black's pawns.
75. Rf5 f3+
The e-pawn push 75... e3 76. Rxf4 exf2 77. Kxf2 was completely winning for white as well.
76. Kg3 e3 77. h5
Here white had 10 winning moves to choose from, and the most natural was one of them: 77. Bxe3 Rf1 78. Bf2 Rh1 79. Rxf3
77... e2 1-0. (diagram)
The game was adjudicated by the TCEC win rule. A possible continuation: 77... e2 78. h6 Rb8 79. Rxf3 Rb1 80. Re3+ Kf6 81. Rxe2 Rb3+ 82. Kf4 Kg6 83. Re6+ Kf7 84. Rb6 Ra3 85. g5 Ra4+ 86. Kg3 Ra3+ 87. Kg2 Ra5 88. g6+ Ke7 89. h7 Rg5+ 90. Bg3 Rh5 91. g7 Rc5 92. g8=Q Rc2+ 93. Bf2 Rxf2+ 94. Kxf2 Kd7 95. Qf7+ Kd8 96. h8=Q#