comment: Trying to create active play in the kingside.
context: 1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... g8f6  4. e1g1  4... f6e4  5. f1e1  5... e4d6  6. f3e5  6... f8e7  7. b5f1  7... c6e5  8. e1e5  8... e8g8  9. d2d4  9... e7f6  10. e5e1  10... f8e8  11. c1f4  11... e8e1  12. d1e1  12... d6e8  13. c2c3  13... d7d5 So far, everything is very familiar in the theory of the Berlin Defense. White's system is very solid and illustrates one of the problems of Black's opening choice for non-elite players: White plays for two possible outcomes, a perspective that (rightly) doesn't make amateur players very happy with Black's position. 14. b1d2  14... c8f5 Supposedly White plays the bishop to d3 to prevent this move, so putting the bishop on f5 has to be critical against 14.Nd2. 15. e1e3  15... e8d6 Improving the knight's position. 16. h2h3  16... h7h6 A new move. Black has other paths to equality, but this doesn't mean that the position is drawn, as Carlsen never gets tired of demonstrating. 17. a1e1  17... f6g5 The plan of exchanging bishops is typical in this position. 18. g2g4  18... g5f4  19. e3f4  19... f5h7 An inaccuracy, since the bishop is better placed on g6, protecting f7. Black can even play f6-Bf7 later, if necessary. 20. c3c4 Changing the pawn structure. 20... d5c4  21. d2c4  21... d6c4  22. f1c4  22... h7g6  23. e1e5 A pleasant square for the rook. White's pieces are more active, but Black is still very solid. 23... g8f8  24. f4e3  24... d8d6  25. h3h4 White has to be fast in order to create threats. 25... d6d7 The queen goes back, at the same time attacking g4, defending f7 and preparing ...Re8. 26. e3f4  26... a8e8  27. h4h5  27... g6h7  28. c4b5 In two particular moments in this game, Carlsen plays extremely subtle moves that make it difficult for Black to defend. This is one of those educational moments. 28... c7c6  29. b5c4 The bishop simply goes back, but now the h2-b8 diagonal is open and the queen gains scope. 29... f7f6 Black is in trouble now. 30. e5e8  30... f8e8  31. f4b8 Now we can appreciate the idea of the Bb5-c4 maneuver. 31... e8e7  32. c4e2 The g4-pawn is protected and White threatens to capture on a7 as well as playing Qh8. 32... h7e4  33. b8a7  33... e4d5  34. a2a4 White is a pawn up with good winning chances. Maybe it's still a draw with perfect play, but this a thankless task against Carlsen.