TCEC Cup 4 Round of 32 Game 73 – Komodo MCTS-Vajolet
|Game||Cup 4, Round of 32, Game 73|
|Links|| TCEC archive|
|Position after 19. O-O-O|
1. d4 Nf6 2. c4 g6
3. Nc3 Bg7 4. e4 d6 5. Be2 b6
As per the Lichess Masters database, move 5... b6 has been played only once at the masters level, leading to a position seen only twice by transposition. But the position after 5. Be2 has been seen approximately 13000 times, which makes this a very rare move. Arguably, the queenside fianchetto is avoided by the masters, since this opening with the locked center often limits the bishop's vision on the a8-h1 diagonal.
6. Be3 O-O 7. Nf3 Bb7 8. Qc2 Ng4
Novelty in the Lichess Masters database.
9. Bg5 c5
Black is asking white to blockade the center, which would restrict black's light square bishop even further. This seems counterproductive for black.
10. d5 Nd7 11. Nd2 h6 12. Bh4 g5
Black is pushing the kingside pawns, as is a typical plan in King's Indian Defense. However, white has not yet castled.
13. Bg3 Nde5 14. h3 Nf6 15. h4 g4 16. h5 Bc8 17. f3 gxf3 18. gxf3 a6 19. O-O-O (diagram)
White castled long. Often in opposite side castling, the game becomes a race of which side is faster to attack. White has a head start with the open g-file and the tempo-gaining move f4. The central pawn structure also arguably favors white, allowing to follow up f4 by (1) e5 pushing the center, or (2) f5 claiming additional control of attacking squares, for instance.
|Position after 25. f5|
19... Kh8 20. Rdg1 Rg8 21. f4 Neg4 22. Bh4
White is clearing the g-file for the rooks, while keeping the bishop pointing at the queen.
22... Bd7 23. Rg3 b5 24. e5
Black is forced to take. If the knight on f6 moves, then Bxg4 wins a piece for white.
24... dxe5 25. f5 (diagram)
A key move for white. The pawn on f5 disconnects black's bishop on d7 from the knight on g4, threatening to win a piece with Bxg4. It further allows white to break through the center.
Note that 25. fxe5 Nxe5 would have released the tension with black able to untangle.
|Position after 33. Ne7|
25... Bf8 26. Bxg4 Nxg4 27. d6
White is now exploiting the pin, threatening dxe7 to win a piece.
27... Qc8 28. Rf1 e6
Note that 28... exd6 would have lost a piece after 29. Qe4 Bc6 30. Qe2. The knight cannot return to f6, since Bxf6+ is a check.
White has multiple winning plans. Perhaps the most straightforward plan was to force a knight to f6. For example: 29. Nde4 exf5 30. Nf6 Bxd6 31. Rxg4. Now black is forced to take back with the rook to avoid mate by Qh7#. 31... Rxg4 32. Nxg4 fxg4 33. Rxf7 renewing the Qh7 mate threat. Black has only one move to avoid the immediate mate: 33... Bf5 34. Bf6+ Kg8 35. Rg7+ Kf8 36. Qd2. White is now threatening Qxh6 with a decisive mating attack.
In the game, white plays a constraining move, instead, and black is forced to push the e-pawns in order to try to save the knight. This allows white to connect the pawns for concrete queening threats.
29. f6 e4 30. Rfg1 e5 31. Ndxe4 bxc4 32. Nd5 32... Bc6 33. Ne7 (diagram)
Black has to take the knight on e7. A move such as 33... Qd7 would quickly lose to 34. Nxg8. Black would lose a full rook in this variation rather than the exchange, since the knight cannot be taken back: 34... Kxg8 35. Rxg4+ and white would still be a rook up with mate soon to follow.
|Position after 42. Kxd1|
33... Bxe7 34. fxe7 Qf5 35. Nf6 Qf4+ 36. Qd2 Nxf6 37. Bxf6+ Qxf6 38. d7
The final key move for white to secure the win. The e7-pawn cannot be taken, as 38... Qxe7 39. Qxh6# would be mate.
38... Kh7 39. Rxg8 Rxg8 40. Rxg8 Qf1+ 41. Qd1 Qxd1+
Black would run out of checks soon, anyways.
42. Kxd1. 1-0 (diagram)
The game was adjudicated as white win. After 42... Bxd7 43. e8=Q Bxe8 44. Rxe8, being a rook up against a mere king and disconnected pawns, it would be an easily winning endgame for white.
- Lichess Masters Database https://lichess.org/yjQpxU15#9 (accessed on 2019-10-20)