Chess puzzle (Advantage)
Moves: 1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Nf6 5. Nc3 Bb4 6. Qd3 O-O 7. Bd2 Re8 8.
f3 a6 9. O-O-O h6 10. g4 Nh7 11. h4 d5 12. Nxd5 Bc5 13. Nf5 Ne5 14. Qe2 b5 15.
Kb1 b4 16. g5 h5 17. g6 fxg6 18. Nfe3 a5 19. Rg1 Nf8 20. f4 Ng4 21. Bxb4 *
Position (FEN): r1bqrnk1/2p3p1/6p1/p1bN3p/1B2PPnP/4N3/PPP1Q3/1K1R1BR1 b - - 0 21
Black to move.
Themes:  Opening  
Puzzle rating: 1908
Best move: axb4