Chess puzzle (Advantage)
Moves: 1. e4 e5 2. f4 d5 3. exd5 e4 4. Be2 Nf6 5. d3 Bf5 6. dxe4 Bxe4 7. Nf3 Bc5 8.
Nc3 O-O 9. Na4 Bd6 10. O-O Re8 11. c4 c6 12. c5 Bf8 13. d6 b6 14. b4 bxc5 15.
bxc5 Qa5 16. Qd4 Nbd7 17. Bd1 Rab8 18. Bb3 Bxf3 19. gxf3 Rb4 20. Qc3 *
Position (FEN): 4rbk1/p2n1ppp/2pP1n2/q1P5/Nr3P2/1BQ2P2/P6P/R1B2RK1 b - - 2 20
Black to move.
Themes:  Middlegame  
Puzzle rating: 1522
Best move: Rxa4