25 December 2020

Commentary: 2020 U.S. Championship, Round 6 (Nakamura - Liang)

The next commentary game, from this year's U.S. Championship, made something of a sensation at the time, given the upset by Black. It shows the strengths of the Caro-Kann Classical and how Black can play sound positional chess and punish White if he is too aggressive. There are a number of other insights that can be gleaned from both sides' decision-making throughout the game, so this was a valuable one to review in detail. 

[Event "U.S. Championship"] [Site "Online"] [Date "2020.10.27"] [Round "6.1"] [White "Nakamura, Hikaru"] [Black "Liang, Awonder"] [Result "0-1"] [ECO "B19"] [WhiteElo "2829"] [BlackElo "2397"] [Annotator "ChessAdmin/Komodo 13.2"] [PlyCount "113"] [EventDate "2020.??.??"] [WhiteTeam "United States"] [BlackTeam "United States"] [WhiteTeamCountry "USA"] [BlackTeamCountry "USA"] 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 e6 { this move-order with an early ...e6 can have independent significance, or transpose back to the "main" main line Caro-Kann. Usually Black plays ...Nd7 here, to prevent Ne5.} 8. Bd3 {this early bishop development deviates from White's standard ideas of h4-h5 or an immediate Ne5. However, in many lines it is normal for White at some point to exchange off the light-square bishop and develop the queen.} Bxd3 {there is no good alternative to exchanging bishops.} 9. Qxd3 Nf6 10. Bf4 Qa5+ {this is the standard reply to the Bf4 development. Black asks White if he wants to maintain the bishop on f4, in which case the c-pawn will have to block the check, or if the bishop will give up its more active placement on f4 and retreat to d2.} 11. c3 Be7 {developing the bishop before the b8-knight, but this seems reasonable, since there is no other good square for it. Liang by doing this gives himself some additional options with the knight, beyond going to d7.} (11... Qa6 {is another idea, but may be more drawish.}) 12. Nf1 $146 {this (new) idea is to redeploy the knight and advance with g2-g4, while leaving the king in the center. While the idea of attacking down the g-file is now standard in some variations, this is an accelerated version of it. White does not seem quite ready to back it up, however.} c5 { Black is able to play this thematic break while his own king is still in the center, since White has no way of taking advantage of it. The light-square bishop is off the board, Black's Qa5 prevents White's queen from using the f1-a6 diagonal, and White's own king is still in the center as well.} 13. N1d2 Qa6 {...O-O and ... cxd4 also look like good options here. The text move pressures White to exchange queens, which is difficult to avoid.} 14. Nc4 { White blocks the queen trade, but at some positional cost. White's queen is now hanging, it is useful to observe, and the Nc4 will also have to be protected.} O-O 15. g4 $6 {White is not as well positioned to back up this kingside aggression as in other lines. Liang nevertheless chooses to avoid taking the g-pawn, which would open up the file.} Nd5 $15 {this is a solid move, anticipating g4-g5 and hitting the bishop.} (15... Nc6 {is recommended by the engines, who have no problem taking the g-pawn in the subsequent variations. White maintains material equality, but Black ends up with an edge.} 16. dxc5 (16. g5 Nh5 17. Bd2 cxd4 18. gxh6 dxc3 19. Bxc3 Nb4 20. Bxb4 Bxb4+ 21. Kf1 Rad8 22. Qe2 g6 $17) 16... Nxg4 17. Rg1 f5 18. Bd6 Bxd6 19. cxd6 Rad8 $17) 16. Be5 (16. Bg3 $5 {is the engine recommendation, preserving the bishop and staying solid on the kingside, but solidity was not Nakamura's original intent with g2-g4.}) 16... Nc6 {Black develops the knight, connects the rooks, and hits the bishop all at once.} 17. g5 h5 {another solid option for defense, reducing the complexity and number of targets for White to go after.} (17... f6 $5 {would be the way to take advantage of White's exposed bishop. For example} 18. gxh6 Nxe5 19. dxe5 Nf4 20. Qe4 Ng2+ 21. Kd1 (21. Ke2 $4 f5 {and the Nc4 is lost.}) 21... f5 $17) 18. g6 $2 {White decides to go all in and try to continue the attack, but Black is now winning. The engines point out the least worst variation, which however would have meant no more dynamic play for White and a solid positional advantage for Black.} (18. dxc5 Bxc5 19. Bg3 $15) 18... cxd4 {despite the pawn thrust, White is not in fact urgently threatening anything on the kingside, so Black can go ahead and start his own counterplay. The text move undermines e5 and starts opening lines for Black's pieces.} 19. Nxd4 (19. cxd4 $2 fxg6 20. Qxg6 Nxe5 $19 {and White has too many open lines to his king.}) 19... Nxd4 {Liang again chooses a more straightforward option, reducing material on the board before proceeding with his ideas.} (19... Rac8 $5 {could be played immediately, but is a more complex line.}) 20. Qxd4 (20. Bxd4 Nf4 21. gxf7+ Rxf7 22. Qf1 Bf6 $19) 20... Rac8 {pressuring the weak Nc4 and controlling the squares on the half-open c-file.} (20... fxg6 $19 {also looks very good.} 21. Bxg7 $2 Rf4 $19) 21. Ne3 Bc5 22. Qe4 Bxe3 {an exchange that reduces White's attacking capability and gives him an isolated e-pawn.} 23. fxe3 fxg6 (23... f6 $5 {would seal off the kingside for good.}) 24. Bd4 ( 24. Qxg6 Rf7 25. Bd4 Ne7 26. Qe4 (26. Qxh5 Nf5 27. Qe2 Qa5 $19 {preparing ... e5.}) 26... Nf5 $17) 24... Rf5 $19 {blocking the attack on g6 and preparing to double rooks. Black is now a pawn up and has much better piece placement and coordination. In particular, the Bd4 is centralized but blocked in and White has to worry about ...e5.} 25. a3 {preparing to castle, but weakening the light squares further.} Rcf8 (25... Kh7 $5 {to protect the g-pawn and free up the Rf5.}) 26. O-O-O Kh7 27. Rhg1 Nf6 {Black is now able to powerfully reposition the knight and cut off any attacking possibilities down the g-file.} 28. Qc2 Ng4 29. e4 Rf1 {Black would be happy exchanging on f1.} 30. c4 R1f3 { here the engines prefer simply exchanging down, given Black's material and positional advantages.} 31. e5 Rc8 {switching targets and prompting White's next move, which unblocks the f1-a6 diagonal and further blocks in the White bishop.} 32. c5 Rcf8 {Liang is not in a rush to press his advantage, possibly due to time control considerations. Several other possibilities exist to make progress.} (32... Rd8) (32... b6) (32... Rh3) 33. Kb1 Rf1 34. Ka2 Rxd1 { now Black goes for the simplifying exchange.} 35. Rxd1 Rd8 {Black's good knight vs. bad bishop situation is now even more clear on the board, along with his material advantage. Although he has doubled g-pawns, later he can get rid of them and have strong passed pawn(s) on the kingside.} 36. Rd2 Qc6 { physically blockading the c-pawn and moving to the more central diagonal.} 37. b4 Rd5 38. Bc3 Ne3 {the engines agree with this idea, which passes up taking the e-pawn in favor of a more dominating central position for Black.} (38... Nxe5 39. Qd1 Rxd2+ 40. Qxd2 $19 {still leaves Black with an advantage, but White has more mobility and the road to victory would likely be harder.}) 39. Qc1 Nf5 40. Qe1 {protecting the h4 pawn, although Black can win it by force if he chooses.} Rxd2+ 41. Bxd2 Qd5+ {comparing this position with the above variation, it's clear that Black's pieces are more dominant.} 42. Kb2 Qd3 ( 42... Nxh4 $5 {apparently Liang did not want to go into a pure queen ending, even two pawns up.} 43. Qxh4 Qxd2+ $19) 43. Bg5 Nd4 44. Qc3 {protecting against further queen penetration. Black now picks up the e-pawn, however.} Qe2+ 45. Kb1 Qxe5 46. a4 {White is desperately seeking counterplay at this point, trying to mobilize the queenside pawn majority.} a6 {the simple way to restrain White's pawns.} 47. Kb2 Qe2+ 48. Qd2 Qe4 {leaving the way open in front of the e-pawn and laterally pressuring the h-pawn, keeping the bishop tied to its defense.} 49. Qc3 e5 50. Qc4 Qg2+ 51. Kb1 Qc6 {using the full power of his queen to influence both sides of the board.} 52. a5 {now Black fully dominates the light squares and White cannot hope to make progress.} Nb5 53. Kc1 Qh1+ 54. Kd2 Nd4 55. Qd3 Qg2+ 56. Kc3 Qa2 {threatening to mate on b3.} 57. Qd1 {White apparently saw the b-pawn would now fall anyway after ...Nb5+ and subsequent Black queen checks, so the game is over.} 0-1

05 December 2020

Videos completed: "Why You Should Study Master Games" by Tatev Abrahamyan


"Why You Should Study Master Games" (parts 1 and 2) are the final videos in the Chess.com series by Tatev Abrahamyan. I've made a point of periodically doing "commentary" annotated games of master (usually GM) level games on this blog, including collecting them in a PGN database available for download on the sidebar link; I posted some previous thoughts on the process in "Analyzing master games for training".

Part 1: Abrahamyan introduces the video with the observation that by studying master games, we will see more ideas and also be able to avoid known mistakes, thereby not having to reinvent the wheel in our own games. Studying historical games therefore is relevant for today's training.

The first example game given is Capablanca - Treybal, in an inferior Stonewall type position for Black. Capablanca fixes the pawn structure and then, as is common in closed positions, can take his time to organize pawn breaks and put his pieces on optimal squares to make progress. Also illustrated are the benefits of a space advantage and White's avoidance of exchanging pieces, which would just make Black's life easier.

The second game is Petrosian - Ledic. The structure is very similar, but without queens on the board. Black gets frustrated and loses more quickly than necessary, but White could have won in any case, with his ability to play on both sides of the board and target Black's weaknesses faster than they could be defended.

Part 2: the theme of modern relevance is continued, with the first example game being again from Capablanca and the second from Carlsen. Capablanca manages to win an even-looking double rook ending, by staying patient and flexible and working to provoke weaknesses, using a minority attack on the kingside to open up the h-file for a rook. 

The second example game is Radjabov-Carlsen from 2012. The structure is again very similar, with the addition of light-squared bishops on both sides. Black wins the endgame using a strategy reminiscent of Capablanca's.

I found the examples useful in both video parts, which together total around 20 minutes, but I felt the broader theme was treated rather perfunctorily. To do it properly, though, would take a lot more content.