1. e2e4  1... c7c5  2. d2d4 The Morra Gambit is a popular weapon with amateurs around the world. Grandmasters are a little more skeptical, but they also like to have fun from time to time. 2... c5d4  3. c2c3  3... d4d3 [%c_effect d3;square;d3;type;Inaccuracy;persistent;true] It has been said, wisely in my opinion, that the only way to refute a gambit is to accept it. In blitz games, however, practical considerations are more important than scientific ones, so Dudin was maybe looking for a position that was easier to play, even if worse. 4. f1d3 White now gets free development and will have the chance to get a \"Maroczy\" structure, with pawns on e4 and c4, and a small advantage. 4... b8c6  5. g1f3  5... d7d6  6. e1g1  6... g8f6  7. h2h3 As we have seen, this is an important move to prevent the development of the bishop to g4. 7... g7g6  8. c3c4  8... f8g7  9. b1c3  9... e8g8  10. c1e3 This is a typical position with a white advantage in this pawn structure, thanks to the greater central control guaranteed by the pawns on c4 and e4. The pawn structure is the most important positional element in chess and, often, it's by looking at it that we decide on game plans. Here Black's plan is related to the three possible breaks: b5 (the most realistic), d5 (practically impossible) and f5 (very difficult). Meanwhile, White seeks to finish development, protect his center, and avoid counterplay from Black. 10... c8e6  11. a1c1  11... d8a5  12. b2b3  12... f8c8 Both sides continue with natural moves. 13. d1d2 I have my doubts about this move, since placing the queen on the same diagonal as the black queen could make a thematic knight jump to d5 difficult. 13... a7a6 Black follows his natural plan of a6-Rab8 and trying to play b5 at some point. 14. f3d4 [%c_effect d4;square;d4;type;Mistake;persistent;true] This move is not ideal if we consider that the side who has a space advantage doesn't want to exchange pieces. 14... c6d4  15. e3d4  15... f6d7 [%c_effect d7;square;d7;type;Inaccuracy;persistent;true] 16. d4g7  16... g8g7  17. d2b2 Despite the exchanges, White maintains an advantage. 17... f7f6  18. f2f4 [%c_effect f4;square;f4;type;Inaccuracy;persistent;true] 18... e6f7 [%c_effect f7;square;f7;type;Inaccuracy;persistent;true] 19. g1h1 Taking the king off the diagonal is useful, but putting the knight on d5 is a tempting option. 19... a8b8  20. c1e1 [%c_effect e1;square;e1;type;Mistake;persistent;true] This move allows Black to achieve the long-awaited counterplay with b7-b5 in the best possible way. 20... b7b5 [%c_effect b5;square;b5;type;GreatFind;persistent;true][%cal db7b5][%c_arrow b7b5;keyPressed;none;from;b7;opacity;0.8;to;b5;persistent;false] Black wins material. 21. b3b4 It's hard to suggest good alternatives. 21... b5c4 [%c_effect c4;square;c4;type;GreatFind;persistent;true] This is probably the move that White missed. 22. d3e2  22... a5b4 Suddenly the position is totally winning for Black. 23. b2d2  23... d7c5  24. e4e5 White desperately tries for some counterplay, but Dudin converts his advantage convincingly. 24... c5d3  25. e5f6  25... e7f6  26. e1b1  26... b4c5  27. b1b8  27... c8b8  28. e2d3  28... c4d3  29. f4f5 