TCEC Season 17 League Q Game 202 – PeSTO - Topple
|Game||Season 17, Qualification League, Game 202|
|Links|| TCEC archive|
|Position after 8. d5|
1. Nf3 Nf6 2. g3 b6 3. Bg2 Bb7 4. O-O e6
End of book.
5. c4 Be7 6. d4 O-O 7. Nc3 Ne4 8. d5
The first sidelining move, going directly to the marginals. The main moves here were Qc2, Bd2, Nxe4. The d5-pawn blocks black's light-square bishop but allows doubling the c-pawn. By the small sample set in the Lichess opening database, the position is now very double-edged.
|Position after 27. Rf1|
8... Nxc3 9. bxc3 Re8(N) 10. Be3 d6 11. dxe6 fxe6 12. h4 Qc8 13. h5 Nd7 14. h6 g6
The h6 pawn will pose a potential long-term problem for black. It is difficult to see how black can challenge it any time soon, and if necessary, white can consider strengthening the h6-pawn with g5. However, keeping the g5 square free for the attacking pieces is useful for now. This said, it is not clear how white can exploit the g7 square, either.
15. a4 a5
White limited black's queenside counterplay with a Maroczy-bind style structure and threatens to break with a5. To defend against the threat, black fixed the pawn structure with a5 of his own.
16. Qc2 Bc6 17. Rfd1 Rb8 18. Nh2 Qb7 19. Bh3 Bf6 20. Ng4 Bh8 21. Bd4 Rf8 22. f4 Rbe8 23. Qd2 e5 24. fxe5 dxe5 25. Be3 Qa6 26. Qa2 Nc5 27. Rf1
The game has reached a critical position. Both sides have some king safety issues, although black is arguably in a bit more precarious position. On the other hand, black's queen-side pawn structure is healthier. Both queens are a bit out of play.
|Position after 35. Kh2|
Pushing the e4-pawn was an inaccuracy. Superficially, black is now able to put some pressure on the c3-pawn and liberate the bishop on h8. But more importantly, white now gains access to the d4-square, and thus, to the all-important d4-h8 diagonal and to the vulnerable g7-square. Computer analysis suggests that white is now close to winning.
A better alternative for black was arguably to go for simplifications, and maintain the pawn on e5 to keep the vulnerable d4-h8 diagonal squares under control. For example, 27... Bd7 28. Rxf8+ Rxf8 29. Bxc5 bxc5. In this variation, white has some pressure, but black has also some counterplay opportunities.
28. Rad1 Bb7
Black's main alternatives were:
- 28... Qa8 29. Bxc5 bxc5 30. Qa3 Rxf1+ 31. Rxf1 Rf8 32. Qxc5 Rxf1+ 33. Bxf1 Bd7 34. Nf2 Bxc3 35. Qxc7 Qc6 36. Qd8+ Kf7 37. e3. White keeps the strong initiative and black is struggling.
- 28... Rxf1+ 29. Rxf1 Qa8 which would transpose back to the first variation.
White took the d-file under control on the previous move and now challenges black's important defender. Without the dark-square bishop, the g7-square becomes quite tender.
29... Bc8 30. Bxh8 Bxg4 31. Bxg4 Kxh8 32. Qd2
The key for white's attack is to get the queen to g5 to support the f6 square for a rook. Black is not quite in time to defend. If black had an extra tempo, pushing the e3-pawn would solve most of the issues while creating some threats for white at the same time.
32... Qxc4 33. Qg5 Kg8
The king preemptively sidesteps a check with a mate threat. The h8-square is also problematic for the king due to back-rank issues. Should the king have stayed in the h8-square, white was threatening 34. Rxf8+ Rxf8 35. Qe5+ mating.
Black's main defensive alternative was 33... Qg8, but it is not any better. For example, 34. Rf6 e3 threatening the Ne4 fork, but allowing the white bishop to join the attack. 35. Rxf8 Qxf8 36. Bf3 Qf5 37. Rd8 Rg8 38. Bd5 Ne6 39. Qxf5 gxf5 40. Rxg8+ Kxg8 41. Bxe6+. White is piece up with an easily winning endgame.
An important move to defend the g3 pawn to prevent black's counterplay with Qxc3 and Qxg3+. Kg2 was the more precise of the two available king moves to protect the pawn. The point here is that white gets to spend a tempo by playing Kh2 next move, which puts black in a bit of a Zugzwang winning faster. Kh2 is the target square for the king to avoid a critical check in an important variation.
Should white have played Kh2 first, black would have an important defensive resource delaying the inevitable: 34. Kh2 Qb3 35. Kg2 e3. This was the key move for black. 36. Rxf8+ Rxf8 37. Qe5 Qf7. Importantly, white cannot now play Rf1 to deflect the queen on f7, since Qxf1+ is a check.
34... Qb3 35. Kh2
Black must now make a move:
- The e-pawn push does not work now. 35... e3 36. Rxf8+ Rxf8 37. Qe5 Qf7. Since the king is on h2 rather than g2, white has the deflecting move Rf1 available, as Qxf1 would not be a check and white would provide the mate on the next move. After 38. Rf1, the continuation might be 38... Re8 39. Qd4 Nb3 40. Qd1 and black would lose material by force. An attempt to keep the material would lose very quickly: 40... Qc4 41. Qd7 with unparryable mate threats.
- The queen cannot leave the a2-g8 diagonal. For example 35... Qxc3 36. Qd5+ Kh8 37. Rxf8+ Rxf8 38. Rd4 and the Qe5+ Kg8 Qg8# threat is unstoppable.
- Trying to keep the queen on the a2-h8 diagonal would also not work: 35... Qc4 36. Rd4 Qb3 37. Rxf8+ Rxf8 38. c4. The c-pawn blocks the black queen with unstoppable threats. For example: 38... Qb1 39. Qd5+ Rf7 40. Be6 Nxe6 41. Qxe6 Qb4 42. Rd8+ Qf8 and black loses the queen.
Black continues with the least bad option.
|Position after 41... Kh8|
35... c6 36. Rxf8+ Rxf8 37. Rd6 Qf7
Checking with the rook would have simply lost a tempo: 37... Rf2+ 38. Kg1 e3 39. Qxe3 Rf8.
White won a pawn and is posing indefensible threats:
- Black has no working counter-threats: 38... Qf2+ 39. Kh3 Qf1+ 40. Kh4 Qh1+ 41. Bh3. The white king is safe and the black queen is misplaced.
- White would like to get the bishop to the a2-g8 diagonal. If allowed, it would be deadly. 38... e3 39. Bf3 Ne6 40. Rxe6 Qxe6 41. Bd5 winning the queen.
- Black also has to prevent a sacrifice on the g6 square. 38... Qc4 39. Rxg6+ and only two more moves until a forced mate. For example: 39... hxg6 40. Qxg6+ Kh8 41. Qg7#
- Staying passive will also go nowhere: 38... Kh8 39. Qe5+ Kg8 40. Rxc5. Black cannot take the rook back as 40... bxc5 41. Be6 wins the queen. Attempt to save the queen is allowing an instant mate. 41... Re8 42. Qg7#
Black chooses to prevent the Qe5/Rxc5/Be6 combination.
38... Re8 39. Rf6 Qb7 40. Qd2 Qc7
A bit more resilient would have been 40... Rf8 but it is a forced mate nevertheless. 41. Rxf8+ Kxf8 42. Qd8+ Kf7 43. Qh8 Qd5 44. Qxh7+ Kf6 45. Qg7+ Kg5 46. h7 Kxg4 47. h8=Q with a forced mate after 9 more moves.
41. Qd5+ Kh8 1-0.
White wins by the TCEC win rule. The end position is a forced mate in 9. Example continuation: 42. Rf7 Qd8 43. Bd7 Nb3 44. Qd6 Kg8 45. Qf4 Nd2 46. Rg7+ Kh8 47. Qf7 Nf3+ 48. exf3 Qh4+ 49. gxh4 exf3 50. Qxe8#.
- https://lichess.org/bVRK8zlA#17 (accessed on 2020-01-11)