context: 1. b2b3  1... c7c5  2. c1b2  2... b8c6  3. g1f3  3... g8f6  4. e2e3  4... g7g6  5. b2f6 Nakamura has played this move a few times before in blitz games. It has pros and cons: White gives up an important bishop and the dark squares are somewhat weakened as a result of the pawn on b3. On the other hand, Black has to play with doubled pawns. It's a move that can only be recommended in rapid time control games. 5... e7f6  6. c2c4  6... d7d5 Black has to open the center before White plays Nc3 and gets a grip on the d5-square. 7. c4d5  7... d8d5  8. b1c3  8... d5d8  9. a1c1  9... c8d7  10. f1b5 It's difficult to say which is the best square for the bishop. It's also not clear what White is going to do after …a7-a6, whether he takes on c6 or comes back. 10... a8c8  11. e1g1  11... a7a6  12. b5e2 Nakamura decides to retreat with the bishop. The other plan is to capture on c6 and play with a quick d2-d4. 12... f8e7  13. c3e4 The knight looks pretty on e4, but it can be attacked with f6-f5 and the pressure on c5 isn't dangerous. 13... d8b6  14. d1c2  14... d7f5  15. d2d3  15... e8g8 Black has a comfortable position. With his usual top-level positional play, Carlsen quickly increases his advantage. 16. c2b2  16... c6b4 An excellent maneuver, bringing the knight to d5. 17. a2a3  17... b4d5  18. f3d2  18... f8d8  19. e2f3  19... f5e6 Black is now preparing f6-f5 followed by Bf6. 20. d2c4  20... b6c7 A bad square for the queen, offering White tactical chances. 21. d3d4  21... c5d4 A bold queen sac that works in the game, but this is not the best decision. 22. c4d6  22... e7d6  23. c1c7  23... d6c7 This was Carlsen's idea, I suppose. He has some compensation for the queen, but Black is now fighting for a draw, although this evaluation will suddenly change. 24. b2d4 The wrong capture. 24... c7e5  25. d4a7  25... b7b6  26. a7a6  26... c8a8  27. a6b5  27... a8a3 Evaluating when a queen sacrifice offers compensation is one of the most difficult tasks in chess. Here it seems that White has a significant material advantage, with queen against rook and bishop (and Black doesn't even have a pawn for that), however the compensation is completely adequate thanks to the very well-placed black pieces. Note that the doubled pawns are not exactly a weakness here, as they ensure the stability of the black position (a knight cannot go to g5, for example) and make the king safer. In the history of chess no player has been as brilliant at assessing unbalanced positions as Garry Kasparov—there are many wonderful examples of his on this topic. 28. f1d1 