1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1c4  3... g8f6  4. d2d3  4... f8c5  5. e1g1  5... a7a6  6. c2c3  6... c5a7  7. a2a4  7... d7d6  8. f1e1  8... e8g8  9. h2h3 Italian move-orders are always full of subtleties. In any case, we have arrived at a very normal position. Black played the traditional a6-Ba7, White the no-less-common c3, a4, Re1, h3, all very logical moves. But now we're in for something very creative. 9... f6h5 I was surprised to find out that Keymer had played this move before. It's beyond my very basic knowledge of this position and all I can say is that he is the only GM to try it and that it's impossible to understand Black's idea (considering White's next move) without very deep study of the position. 10. c1g5 This is the problem, as the knight is more or less forced to come back. 10... h5f6 White often places the bishop on g5 of his own free will, whereas here he was provoked into doing so, gaining tempo. If it were one of my students playing, I'd spend hours explaining to him the importance of development in the opening, but playing with Black is one of the best players in the world, trying this for the second time, and with the blessing of computer analysis. This just shows how difficult chess is and how the rules are made to be broken (but only after you've mastered them all). 11. d3d4 I found a new game in this position, played in blitz, which occurred by a different move-order. This is just to say that this move is not a new one. 11... h7h6  12. g5h4  12... g7g5 This is Black's only idea with all this provocation: to show that this pin is worthless to White. 13. f3g5 [%c_effect g5;square;g5;type;GreatFind;persistent;true] I don't know if it's scientifically correct to put an exclamation mark next to this move, but I'll pay homage to all those who love this sacrifice, especially those who have the courage to play it (which doesn't always end well). Praggnanandhaa said he didn't think Keymer would repeat this dubious line, but he was prepared just in case. A true professional. 13... h6g5  14. h4g5  14... g8h7 [%c_effect h7;square;h7;type;GreatFind;persistent;true] The only defense, played almost instantly by Keymer. 15. d1f3  15... h7g6  16. g5h4  16... e5d4 Forced again. 17. f3g3  17... g6h7  18. h4g5 Interesting back and forth play with the dark-squared bishop. 18... f8h8 One more forced move. 19. b1d2 After this move, Keymer sank into deep thought. 19... d8g8 A good move, bringing the queen to the defense. 20. e4e5 [%c_effect e5;square;e5;type;GreatFind;persistent;true] 20... f6h5 [%c_effect h5;square;h5;type;GreatFind;persistent;true] Another forced move. I've already lost count of how many Keymer has played up to this point. 21. g3h4  21... g8g6  22. g5f6  22... h8g8  23. c4d5  23... c8f5 Black has other options. 24. d5f3 All this was prepared by Praggnanandhaa. Unbelievable. 24... a8e8 [%c_effect e8;square;e8;type;Mistake;persistent;true] Up to this point, perfect play by both sides, but this move is a mistake. 25. g2g3 [%c_effect g3;square;g3;type;GreatFind;persistent;true] White prevents mating themes on g2 and can now take on h5. 25... h7h6 [%c_effect h6;square;h6;type;Mistake;persistent;true] 26. g3g4 [%c_effect g4;square;g4;type;GreatFind;persistent;true] The number of subtle moves that White plays to conduct the attack is impressive. 26... d4c3  27. b2c3  27... c6e5  28. g4g5  28... g6g5  29. f6g5  29... g8g5  30. g1h2  30... e5g6 [%c_effect g6;square;g6;type;Inaccuracy;persistent;true] 31. h4g5  31... h6g5  32. e1e8 The position is finally clarified: White has a decisive material advantage and the rest is easy.