Commentary - Dortmund 2013 round 6

The Kramnik-Fridman game from round 6 of the Dortmund tournament is an outstanding example of high-level master chess.  Some thoughts on it, in addition to the game annotations:

• Kramnik adopts a strategy in the English vs. Queen's Gambit Declined (QGD) setup that he is very familiar with. Although White's setup at first glance appears passive, in fact it contains significant kingside attacking prospects, once Black's early pressure in the center is dealt with. The fact that overall White has scored close to 60 percent from the inoffensive-looking position on move 8 is, I suspect, evidence that the White players who adopt this strategy simply understand the position to a much deeper level than their opponents.
• Tactical defense is used multiple times by Kramnik in this game to good effect, covering his weaknesses in a dynamic fashion and not tying down his pieces unnecessarily.
• Kramnik' sacrificial attacking idea that begins with 20. f6 is something born from deep positional understanding of the problems Black will face afterwards on the kingside.  It takes Houdini a few moves down its primary path before it is able to see in its evaluation function that White has full compensation for the material.  (Another good example of the pitfalls of computer analysis for the uninitiated.)
• The combination starting on move 29 is the highlight of the game and is worth looking at closely, especially because the initial knight sacrifice appears to come out of nowhere.

[Event "41st GM"] [Site "Dortmund GER"] [Date "2013.08.01"] [Round "6.5"] [White "Kramnik, Vladimir"] [Black "Fridman, Daniel"] [Result "1-0"] [ECO "A13"] [WhiteElo "2784"] [BlackElo "2629"] [Annotator "ChessAdmin/Houdini"] [PlyCount "67"] [EventDate "2013.07.26"] 1. c4 e6 2. Nf3 d5 3. b3 {this keeps the game in English territory, rather than transposing to the QGD.} Nf6 4. g3 {this would allow Black the ...d4 advance if desired. In practice, if Black has intended to play a QGD from the start, he probably will continue with standard moves as in the game.} Be7 5. Bg2 O-O 6. O-O c5 7. Bb2 {by this point the role reversal is clear, Black is going for a strong, classical center while White seeks to undermine it from the flanks and restrain further Black advances.} Nc6 8. e3 {from this innocuous-looking position, White has scored almost 60 percent.} b6 9. Nc3 dxc4 10. bxc4 Qd3 {the point of this move is to disrupt White's piece setup, rather than achieve anything directly for Black.} 11. Ne1 Qd7 12. Qe2 Bb7 13. f4 { White evaluates that his future strategic chances lie on the kingside, so starts the expanion process.} Rfd8 {until this point, we have been following the game Kosten-Hernando Rodrigo (given below) which contains a more normal attacking plan for White.} (13... Na5 14. d3 Bxg2 15. Qxg2 Rfd8 16. g4 Ne8 17. Rd1 Nd6 18. Nf3 Qb7 19. e4 b5 20. e5 Ndxc4 21. dxc4 Nxc4 22. Bc1 b4 23. Qe2 Rxd1 24. Nxd1 Nb6 25. Nf2 a5 26. Ne4 Qa6 27. Qg2 Qc4 28. Re1 a4 29. f5 Nd5 30. Nd6 Qd3 31. fxe6 fxe6 32. Qe2 Qxe2 33. Rxe2 c4 34. Nd4 b3 35. axb3 Bxd6 36. exd6 axb3 37. Nxe6 Nc3 38. Re1 Na2 39. Bb2 Nb4 40. d7 Nc6 41. Ng5 {1-0 (41) Kosten,A (2516)-Hernando Rodrigo,J (2381) Castelldefels 2004}) 14. Rd1 Nb4 15. d3 {the pawn will actually be stronger here, due to a tactical defense, and cover e4.} Bxg2 16. Nxg2 a6 (16... Nxd3 $2 17. Ne1 {and with the knight pinned and no new defenders coming to its rescue, the best Black can do is capture on f4 and get two pawns for the piece.}) 17. a3 Nc6 18. g4 {White's kingside attack now gets started.} Ne8 19. f5 Nd6 20. f6 {the start of a deep and unusual sacrificial idea by Kramnik. One wonders what he would have done in the event of 19...exf5.} Bxf6 21. Rxf6 {otherwise the previous move makes no sense.} gxf6 22. Nf4 Ne5 23. Nh5 Qe7 24. Rf1 {here Houdini's evaluation is that White has full compensation for the material.} Nd7 25. Qg2 (25. Qf2 { would be the more obvious follow-up.}) 25... h6 26. h4 Kf8 {this appears to be where Black starts going astray with his defense. Houdini recommends instead looking to start counterplay on the queenside.} (26... b5) 27. Qg3 Ke8 28. Qf4 Qf8 $2 {this appears to be a normal response to the threat against h6, but allows the following combination.} 29. Nd5 $1 {a very non-obvious move. White's pieces do not appear at first glance to be sufficiently coordinated for a combination and there are plenty of defenders. However, the Black king's very limited space and the weaknesses of f6 and g7 are the elements from which the combination is constructed.} exd5 30. Bxf6 {the immediate threat is Ng7+} Ne5 {to give the king an escape square on d7} (30... Nxf6 31. Nxf6+ Ke7 32. Qe5#) 31. Qxe5+ Kd7 32. Bg7 {the combination now morphs from mate threat to trapping Black's queen.} Re8 33. Nf6+ Kc7 34. Qa1 {the Bg7 is protected tactically by the knight check discovery White would have after ... Qxg7.} 1-0