Chess puzzle (Advantage)
Moves: 1. c4 e5 2. e3 Nf6 3. Qc2 d5 4. cxd5 Nxd5 5. Bb5+ Bd7 6. Bxd7+ Nxd7 7. a3 Qg5
8. g3 O-O-O 9. d4 exd4 10. exd4 Qg4 11. Ne2 Re8 12. Nc3 Qxd4 13. Nxd5 Qxd5 14.
O-O Bc5 15. Bf4 Ne5 16. Bxe5 Rxe5 17. b4 Bb6 18. Nf4 Qf3 19. a4 Rg5 20. Ng2 a6
21. b5 f5 *
Position (FEN): 2k4r/1pp3pp/pb6/1P3pr1/P7/5qP1/2Q2PNP/R4RK1 w - - 0 22
White to move.
Themes:  Middlegame  
Puzzle rating: 2035
Best move: a5