1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... a7a6  4. b5a4  4... g8f6  5. d2d3  5... f8c5  6. c1g5 It seems there's much left to discover, even in such heavily studied openings like the Ruy Lopez. There are not many games in this position, and in a couple of moves, the game will leave theoretical territory. 6... h7h6  7. g5h4  7... d7d6  8. d3d4 [%c_effect d4;square;d4;type;GreatFind;persistent;true] A new one in this position. I'm not sure whether this was preparation or not, but it's the computer's first choice. White doesn't get an advantage, but it's a new position with a lot to play for. 8... e5d4  9. f3d4  9... c8d7  10. a4c6  10... b7c6  11. b1c3  11... e8g8  12. d1d3 [%c_effect d3;square;d3;type;GreatFind;persistent;true] Carlsen wants to send the king to the queenside to sharpen the game. This is more dangerous than castling short. 12... c5b4  13. d4e2 [%c_effect e2;square;e2;type;GreatFind;persistent;true] A necessary prophylactic move. 13... d8e7  14. e1c1  14... f8e8  15. f2f3  15... e7e5 On the board, we have a complicated middlegame fight with chances for both sides, which is not a bad situation for Carlsen. His next move, however, is a blunder. 16. a2a3 [%c_effect a3;square;a3;type;Mistake;persistent;true] White has a few options: 16... b4c3  17. d3c3  17... e5c3 [%c_effect c3;square;c3;type;Mistake;persistent;true] Keymer returns the favor. 18. e2c3 The position is more or less equal, but having realized that he was granted a second chance after his big mistake, Carlsen must have felt it was time to show his true chess. 18... f6h7  19. g2g4  19... f7f6  20. h2h3  20... h7f8 Nice maneuvering by Keymer. 21. h4g3  21... f8e6  22. h3h4  22... g8f7  23. h4h5  23... a8d8  24. h1e1  24... d7c8  25. d1d3  25... c8b7  26. c3b1 [%c_effect b1;square;b1;type;Interesting;persistent;true] 26... c6c5  27. c2c4  27... b7c6  28. b2b3  28... d8b8  29. g3f2  29... b8b7  30. b1d2 Both sides continue playing well, and the evaluation doesn't change. 30... e8b8  31. f2e3  31... f7g8 Freeing the f7-square for the knight. 32. c1c2  32... e6d8  33. f3f4  33... a6a5 Carlsen mentioned that Keymer shouldn't have allowed e4-e5. From what I understand, he thinks 33...Nf7 is better, and the computer agrees. 34. e4e5 [%c_effect e5;square;e5;type;GreatFind;persistent;true] 34... f6e5  35. f4e5  35... d8f7  36. e3f4 The position is still equal, but it's more difficult to play with Black now. 36... d6e5  37. f4e5  37... a5a4  38. e5c3 [%c_effect c3;square;c3;type;GreatFind;persistent;true] 38... a4b3  39. c2b2 The b3-pawn will be captured sooner or later. 39... b8e8  40. e1e8  40... c6e8  41. d3d5  41... e8c6  42. d5c5  42... c6d7 The g4-pawn falls. Keymer is defending very well, but Carlsen keeps pressing. 43. c3d4  43... d7g4  44. a3a4 The a-pawn is very dangerous. 44... f7g5 Threatening 45...Ne6. 45. d4e3  45... g5f3  46. d2f3  46... g4f3  47. a4a5  47... b7b4 [%c_effect b4;square;b4;type;GreatFind;persistent;true] The only move. The rook must go behind the pawn. 48. e3d2  48... b4a4  49. b2b3  49... f3d1  50. b3c3 The endgame is still dangerous for Black. 50... c7c6  51. c3d4 