context: 1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... g8e7 This is the Cozio Variation of the Ruy Lopez, and it has appeared in other \"Games of the Day.\" Nakamura has used it a few times with Black but not often. He played a game with White against Caruana in 2024 that may have sparked his idea to play it with the other color. 4. b1c3 White has three other major moves. 4... e7g6  5. d2d4  5... e5d4  6. f3d4  6... c6d4  7. d1d4  7... c7c6  8. b5e2  8... d8b6  9. d4d3 All of White's moves are very natural, and this is a critical line for Black's system. 9... f8e7  10. a2a4  10... a7a5  11. e1g1  11... e8g8  12. c1e3 Now White can play this move without having to sacrifice a pawn, since with the inclusion of a4-a5, the queen is left without a square. 12... e7c5  13. e3c5  13... b6c5  14. a1d1  14... g6e5 A bad move, since the knight will soon be attacked by f4 and White remains with a firm grip on the dark squares. 15. d3d6  15... c5d6  16. d1d6 The endgame is nearly winning for White with a development advantage and better pawn structure. Black has trouble getting the bishop into play, and the backward d-pawn is a long-term weakness. 16... f7f6  17. f2f4  17... e5f7  18. e2c4  18... g8h8  19. d6d4 Carlsen decides to keep the bishop to advance the pawn to e5 to create problems quickly for Black. 19... b7b6  20. e4e5  20... f7h6  21. c3e4  21... h6f5  22. d4d3  22... d7d5 A good practical chance, otherwise Black is in a melancholic position with no counterplay. 23. e5d6  23... c8d7  24. f1e1  24... a8e8  25. g1f2 White is a clear pawn up, but surprisingly the game will have some adventures. 25... g7g5  26. d3b3 An uncharacteristic mistake by Carlsen, who is normally surgical when converting winning positions. 26... g5f4  27. b3b6  27... f5e3 Suddenly Black has gained counterplay. 28. c4d3  28... e3g4  29. f2f3 The other moves don't change much. 29... f6f5  30. e4c5 This is the winning idea. 30... e8e1  31. c5d7  31... f8d8  32. b6b8 This move gives Black a chance to save the game. 32... e1e8  33. b8d8  33... e8d8  34. d3f5  34... g4h6  35. f3f4 This looks like a pretty nice move, but it actually isn't very accurate. 35... h6f7  36. d7e5  36... f7d6  37. e5c6  37... d8f8  38. c6d4 White has three pawns for the exchange, and at first I thought this was a clear win, but the computer shows that Black can still defend. 38... h8g8  39. b2b3  39... g8f7 Now White is again winning. 40. f5h7  40... f8h8  41. f4e5  41... d6b7  42. h7e4  42... h8e8 