context: 1. a1b3 Interestingly, in this starting position the weakest square is a2-a7, which has no protection. In the conventional chess position the weakest point is f2-f7, which at least has the protection of the king. The move 1.f4 therefore creates an immediate threat right after the first move. 1.Nb3 brings the knight into play and protects the weakness on a2. This move was played in all the games of the round. 1... d8c6 There are many alternatives. The opening theory in each position of Freestyle allows for many hours of discoveries. 2. e2e4  2... e7e5  3. f2f3  3... f7f6  4. d1c3  4... a8b6  5. c1b1 The moves by both players up to this point were very logical. Firouzja, needing a win, decides to spice things up a little. 5... f8b4  6. e1g3  6... e8e7  7. c3b5 This looks like a strange move to me, but the computer doesn't consider it wrong. 7... a7a6  8. b5c3 By going up and down with the knight, the b6-square has been weakened and I think this was Keymer's plan. He now can consider capturing on b6 in a better version, but Firouzja also has some ideas. 8... b4c3  9. d2c3  9... b6a4  10. g1e3  10... b7b5 An excellent move. More than going for b5-b4, which can be met by c3-c4, Firouzja secures the c4-square for the bishop. 11. f3f4  11... g8c4  12. g3g4 This allows Black to capture on f4. 12... e5f4  13. g4f4  13... c6e5 with firm control of the e5-square and a potential attack on the queenside, Black is clearly better. 14. e3d4  14... c8h8 As is usually the case, after both sides have castled the position on the board no longer looks strange to the standards we're used to. Black has a clear plan of attack on the queenside, while it's not clear what White should do. 15. f4g3 The best plan is to reduce Black's attacking potential. The queen is helpful for defending the king along the third rank. 15... c4f7 An interesting move, vacating the c4-square for the knight. 16. d4e5 It's necessary to capture the knight before it goes to c4. 16... f6e5  17. f1e2  17... c7c5 Black starts a pawn advance on the queenside. White's position is very unpleasant. 18. d1f1 The old problem of which rook to move. Keymer probably considered it would be useful to give the king some space in case it needs to run from the attack, but the rook was useful on d1. 18... c5c4  19. b3d2  19... e7c5 Protecting the pawn and preparing b5-b4, but there's a better move with the same idea. 20. f1f5 White manages to find counterplay. 20... b5b4  21. d2b1 A sad move to play. 21... b4c3  22. b1c3  22... a4b2  23. h1f1 Despite having his king protection destroyed, White is not yet receiving a mating attack. Black must be patient. 23... c5a3  24. c1d2  24... a3d6  25. d2e1  25... f7e6  26. g3e5 Now White is just a pawn up. 26... d6b4  27. f5f8  27... b8f8  28. f1f8  28... g8f8  29. e5f4 Keymer just needed a draw to qualify, so he plays for this result. 29... f8g8  30. f4d2  30... b4c5  31. h2h3  31... a6a5  32. e1f1  32... c5f8  33. f1e1  33... f8f6 Of course drawing and losing are the same to Firouzja, so he keeps fighting. 34. e2g4  34... h7h5  35. g4e6  35... d7e6  36. e1e2  36... a5a4  37. a2a3  37... f6e7  38. c3b5  38... e7c5  39. d2b4 It was clear by this point that the match destiny was sealed. 39... c5g1  40. b4b2  40... g1g2  41. e2d1 There's no perpetual now. 41... g2h3  42. b2e5  42... h3g4  43. d1d2  43... h5h4  44. b5d4 White is in time to stop the pawn. 44... h4h3  45. d2c3  45... g8f7  46. c3b4  46... g4g6  47. d4f3  47... g6h6  48. e5g3  48... f7g8  49. b4a4 