1. g1f3  1... d7d5  2. g2g3  2... g7g6  3. f1g2  3... f8g7  4. d2d4  4... g8f6  5. c2c4  5... c7c6  6. e1g1  6... e8g8  7. a2a4 Only the eighth most popular move in this well-known position. 7... a7a5 A natural reaction, fixing the queenside. The b4-square is weakened, but White has an idea: 8. c4d5 [%c_effect d5;square;d5;type;GreatFind;persistent;true] Now if Black captures with the pawn, White gets the b5-square. If she captures with the knight, then White gets the center. 8... c6d5 [%c_effect d5;square;d5;type;GreatFind;persistent;true] The most accurate. White has more chances to fight for an advantage after the capture with the knight. 9. b1c3  9... b8c6  10. d1b3 A critical position. 10... c8g4 A new move, sacrificing the b7-pawn. 11. b3b7 White accepts the challenge. 11... c6b4  12. c1f4 Necessary to avoid 12...Rb8. 12... f6h5  13. f4c7 [%c_effect c7;square;c7;type;Inaccuracy;persistent;true] White can look for an improvement at this point. Both 13.Qc7 and 13.Be5 are likely better. 13... d8d7  14. c3b5 A strange situation has occurred. White is a pawn up, but his pieces are clumsy on the queenside. What should Black do $2 14... a8a6 [%c_effect a6;square;a6;type;Mistake;persistent;true] The beginning of a wrong plan. 15. f1c1  15... f8a8 The idea is Nc6-d8, but Black is not in time. 16. c1c5 [%c_effect c5;square;c5;type;GreatFind;persistent;true] 16... d7e8  17. c7a5 [%c_effect a5;square;a5;type;Interesting;persistent;true] A nice move, leading to an endgame a pawn up for White. 17... a6a5  18. b5c7  18... e8d7  19. b7b4  19... a5a4  20. a1a4  20... a8a4 