1. c2c4  1... g8f6  2. g1f3  2... e7e6  3. g2g3  3... d7d5  4. f1g2  4... f8e7  5. e1g1  5... e8g8  6. d2d3 Reti instead of the Catalan. 6... a7a5  7. b1c3  7... c7c6 Too passive. 8. e2e4 Carlsen is immediately taking advantage of his opponent's sloppy play. He is heading to a favorable King's Indian Attack setup. 8... b8a6 Alas, the knight is too far away from the key d3-square. 9. e4e5  9... f6d7  10. h2h4 Carlsen tricked his opponent in the opening and has a perfect King's Indian Attack with an easy step-by-step assault on the kingside coming. 10... b7b6  11. f1e1  11... c8b7  12. c4d5 This is a good moment to fix the pawn structure in the center. 12... c6d5  13. d3d4  13... b7c6 Niemann in turn hopes to generate enough play on the queenside to keep his opponent busy, but this is too optimistic here. 14. f3g5 A strong beginning of the attack. 14... b6b5  15. d1h5  15... e7g5  16. c1g5  16... d8e8 Hoping for a positional trick. 17. h5g4 Which is naturally rejected. 17... g8h8  18. a1c1 A very instructive move $1 Carlsen would not miss a chance to improve a piece with a tempo $1 18... d7b6  19. c3e2 The second knight is heading toward the kingside, and the game is practically over $1 19... a6b4  20. e2f4  20... b4a2 