comment: Otherwise White plays h7-Rh6.
context: 1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... g8f6  4. e1g1  4... f6e4  5. d2d4  5... e4d6  6. b5c6  6... d7c6  7. d4e5  7... d6f5  8. d1d8  8... e8d8 Vachier-Lagrave from time to time still tries to defeat the Berlin Defense with the endgame that so exasperated Kasparov in his 2000 match against Kramnik. At the super-GM level, Black has certainly defended well, but I have the impression that amateur chess players underestimate the difficulty of playing this endgame with Black. 9. h2h3  9... c8d7 [%c_arrow d8c8;keyPressed;none;from;d8;opacity;0.8;to;c8;persistent;false,b7b6;keyPressed;none;from;b7;opacity;0.8;to;b6;persistent;false,c8b7;keyPressed;none;from;c8;opacity;0.8;to;b7;persistent;false] Taking the king to c8 and then playing b6-Kb7 is one of the most combative plans for Black. 10. b1c3  10... h7h6 An important move to prevent Ng5. 11. b2b3 White prepares the development of the bishop on b2—so far, all his moves are very natural. 11... c6c5 [%c_highlight c6;keyPressed;none;opacity;0.8;square;c6;persistent;false,d5;keyPressed;none;opacity;0.8;square;d5;persistent;false] This move is only the third most popular choice for Black, but it has been played by Firouzja before. Advancing the pawn to c5 is generally a difficult decision: on the one hand, Black gains the c6-square for a bishop or knight; on the other, the d5-square becomes available for the white knight. 12. f1d1  12... d8c8  13. c3d5  13... a7a5  14. a2a4  14... g7g5 [%c_effect g5;square;g5;type;GreatFind;persistent;true] A typical Berlin move, gaining space on the kingside, which makes it difficult for White's pawns to advance. Furthermore, the knight cannot use the f4 square anymore. 15. c2c4 Reinforcing the knight's position and preventing any attempt by Black related to c5-c4. 15... d7e6  16. c1b2  16... f5e7 [%c_effect e7;square;e7;type;GreatFind;persistent;true] 17. h3h4  17... g5g4  18. f3h2 The first new move of the game. 18... h6h5  19. f2f4 Now Black has a difficult positional decision: should he capture en passant  $2 19... e7f5  20. h2f1  20... a8a6  21. g2g3  21... f5d4  22. f1d2  22... c7c6  23. d5e3  23... a6b6  24. a1b1 The position becomes dangerous for Black. 24... c8c7 [%c_effect c7;square;c7;type;Mistake;persistent;true] 25. g1f2 Preparing Bc3 without Black having a check on e2. 25... f8e7  26. b2c3 [%c_effect c3;square;c3;type;GreatFind;persistent;true] 26... h8a8  27. d2e4  27... d4f5  28. e3c2 [%c_effect c2;square;c2;type;Mistake;persistent;true] 28... b6a6  29. d1d2  29... a8d8  30. b1d1  30... d8d2  31. d1d2  31... a6a8  32. c2e3  32... b7b6  33. e3f5  33... e6f5  34. e4d6 White's attacking plan has greatly reduced in strength since, unlike the positions analyzed previously, Black doesn't have a rook out of play. 34... e7d6  35. d2d6  35... f5e6 The game appears to be heading toward a draw. 36. f2e3 [%c_arrow f7f5;keyPressed;none;from;f7;opacity;0.8;to;f5;persistent;false] 36... a8e8 Black's plan now is to play f7-f5, leading to an inevitable draw. 37. f4f5 [%c_effect f5;square;f5;type;Interesting;persistent;true] The only winning attempt. 37... e6f5  38. e3f4  38... f5c2 The endgame becomes tactical, an area in which the two players usually shine. 39. d6f6  39... e8e7  40. f4g5  40... c2b3  41. g5h5  41... b3c4  42. h5g4  42... c4e6  43. g4f4  43... b6b5  44. c3a5  44... c7d7  45. a5b6  45... b5a4 Black has good options: 46. b6c5  46... e7e8  47. h4h5  47... e8a8  48. c5a3  48... c6c5 [%c_effect c5;square;c5;type;Mistake;persistent;true] This is the losing mistake. 49. h5h6 