1. d2d4  1... g7g6  2. e2e4  2... f8g7  3. g1f3  3... d7d6  4. f1c4  4... a7a6 A must-win situation requires  extreme measures. And preferably no theory at all. 5. e1g1  5... b7b5  6. c4b3  6... c8b7  7. f1e1  7... e7e6  8. c2c3  8... b8d7  9. a2a4  9... g8f6  10. b1d2  10... e8g8  11. b3c2 Dubov plays the Ruy Lopez and does not care what his opponent does... 11... c7c5  12. d2f1  12... d8c7  13. f1g3 All very logical. 13... f8c8  14. c2d3  14... b5b4  15. a4a5  15... c5c4 A risky transposition to a French pawn  structure. This move practically wins the a5 pawn in the long run, but  leaves the kingside exposed. 16. d3f1  16... b4b3  17. a1a4  17... d6d5  18. e4e5  18... f6e8  19. h2h4 The pawn chains are clearly  indicating on which side the players will attack. 19... b7c6  20. a4a1  20... c8b8  21. h4h5  21... b8b5  22. f3g5  22... d7f8 Clears the seventh rank for the defense.