1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. c4d5 The first important moment. Nepomniachtchi has been confidently playing the line with 4. Nc3 c5, which sometimes leads to long forced draws. This system was played by So in this round. Instead of getting into a theoretical battle, Carlsen tries to take the game into his own turf. 4... e6d5  5. b1c3  5... c7c6 The problem for White in this line is that there is no way to prevent the black bishop from developing to f5. Usually in the Queen's Gambit exchange variation it's possible to avoid this by placing a bishop on d3 or the queen on c2. In this game's move order, Black can force the development of the bishop, even if he has to play g6 first. 6. c1f4 The third most popular move, simply ignoring 6...Bf5. 6... c8f5  7. e2e3  7... b8d7  8. h2h3 With this move White plans to play g2-g4 and create some annoyance for the f5-bishop. 8... f8e7  9. g2g4  9... f5e4 Curiously this move was tried before by Carlsen himself in a blitz game against Anand. 10. f1e2 The first new move. 10... d8b6  11. d1b3  11... b6b3  12. a2b3 White doesn't have any particular advantage, but Carlsen thrives in this type of position. 12... e4g6  13. f3h4 Going after the bishop. From now on, Nepomniachtchi starts to play small inaccuracies. 13... e7b4 White gets a small plus after this move. 13...Ne4 or 13...Bc2 are more dynamic moves. 14. h4g6  14... h7g6  15. f2f3 Taking the e4-square from the knight and preparing Kf2-g2. 15... d7f8  16. e1f2  16... f8e6  17. f4g3 White has the bishop pair and a small advantage in this endgame. 17... e8e7  18. h3h4  18... a7a6  19. f2g2  19... a8d8  20. g3f2 The problem with Black's position is that he has no active plan. I suspect this is particulartly difficult for Nepomniachtchi, being such an agressive player that thrives in positions where he has the initiative. 20... b4d6 The computer suggests the strange 20...Kd7 followed by a plan with Ng8-e7. This is simply unintelligible for humans. With this retreat, Nepomniachtchi wants, I suppose, to prepare c6-c5 in some way, as this is his only active attempt. But Carlsen is going to neutralize this idea. 21. e2d3  21... d6b8  22. c3a4  22... b8d6  23. f2e1 White wants to play b4, as this will shut the c5 break forever. Maybe Black should accept this fate, but he decides to act. 23... c6c5  24. a4c5  24... e6c5  25. d4c5  25... d6c5  26. e1d2  26... h8e8  27. b3b4  27... c5b6  28. b4b5 Chess looks simple in the hands of such a magnificent player. White not only improves the pawn structure, but actually might start an attack on Black's king. 28... a6a5 Black decides to sacrifice a pawn. 29. d2a5  29... b6a5  30. a1a5  30... e7d6  31. g2f2  31... e8e7  32. h1d1  32... d8h8  33. g4g5  33... f6d7  34. a5a4  34... d7c5  35. a4g4 The threat now is 36.Bc4. 35... d6c7  36. d3b1  36... e7e5  37. b1a2 Now the d5-pawn is lost. 37... f7f6  38. g5f6 