1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1c4  3... g8f6  4. f3g5 A sharp line that indicates Firouzja's aggressive intentions. Caruana had a painful defeat against Nakamura in this line this year, in the last round of Norway Chess. 4... d7d5  5. e4d5  5... c6a5  6. c4b5  6... c7c6  7. d5c6  7... b7c6  8. b5d3  8... f6d5  9. h2h4 [%c_effect h4;square;h4;type;Interesting;persistent;true] A surprising choice, as this is a move that doesn't have a good reputation and leads to chaotic positions. 9... h7h6  10. d1h5  10... d8f6  11. g5e4 Firouzja recently had to face this line with the black pieces. Perhaps this inspired him to try playing the position with the other color. 11... f6e6  12. b2b3  12... g7g6  13. h5e2  13... f7f5 In the post-game interview Caruana said that he couldn't remember his analysis of this variation and that if you don't check a line for a week or two the details fade very quickly. On the one hand, it's good to know that even a chess player of his stature has problems remembering the analysis. On the other hand, this gives an idea of the amount of work required at the highest level, even if it's simply reviewing your notes. 14. e4c3  14... f8g7  15. c1b2 This natural move is a novelty. 15... e8g8  16. b1a3  16... e5e4  17. d3c4  17... a5c4  18. e2c4  18... a8b8 After this move, Firouzja started to think, an indication that his opening analysis ended at this point. 19. e1c1 A natural move, but here it's more accurate to play 19... b8b4 [%c_effect b4;square;b4;type;GreatFind;persistent;true] This is the problem for White—his queen can no longer go to d4. 20. c4e2  20... a7a5 The advance of the a-pawn is the natural plan to create a queenside attack. 21. h1e1 [%c_effect e1;square;e1;type;Mistake;persistent;true] Caruana said he felt this was a very strange move. 21... a5a4 [%c_effect a4;square;a4;type;Mistake;persistent;true] 22. g2g3 [%c_effect g3;square;g3;type;Inaccuracy;persistent;true] 22... a4b3  23. a2b3  23... e6d6  24. f2f3 [%c_effect f3;square;f3;type;GreatFind;persistent;true] 24... d6c5  25. a3b1 An ambitious choice. 25... f8e8  26. f3e4  26... f5e4  27. b2a3  27... c5a5  28. a3b4  28... d5b4 It's clear that Black has good compensation: the g7-bishop is too strong and White's king is insecure. 29. d2d4  29... e4e3  30. c1b2 [%c_effect b2;square;b2;type;Mistake;persistent;true] This puts the king in a dangerous spot. 30... h6h5 [%c_effect h5;square;h5;type;GreatFind;persistent;true] My favorite move of the game. The bishop is ready to go to g4. 31. b1a3  31... c8g4  32. e2c4  32... g8h7  33. c4f7 A desperate attempt to create counterplay. 33... e8f8  34. f7e7  34... g4d1  35. e1d1  35... f8f2 [%c_effect f2;square;f2;type;Mistake;persistent;true] This lets the win slip away. 36. c3e4 [%c_effect e4;square;e4;type;Mistake;persistent;true] 36... f2c2  37. b2b1  37... c2f2 [%c_effect f2;square;f2;type;GreatFind;persistent;true] The rook must come back to rescue the king from the checks. 38. e4g5  38... h7h8  39. e7e8  39... f2f8  40. e8g6  40... a5f5 [%c_effect f5;square;f5;type;GreatFind;persistent;true]