Chess puzzle (Advantage)
Opening: Ruy_Lopez, Ruy_Lopez_Closed
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. c3 b5 7. Bc2 d6 8. d4
O-O 9. d5 Nb8 10. h3 c6 11. b3 cxd5 12. exd5 Bb7 13. c4 bxc4 14. bxc4 Nbd7 15.
Nc3 Rc8 16. Qd3 Nc5 17. Qe2 Qa5 18. Na4 *
Position (FEN): 2r2rk1/1b2bppp/p2p1n2/q1nPp3/N1P5/5N1P/P1B1QPP1/R1B2RK1 b - - 8 18
Black to move.
Themes:  Middlegame  
Puzzle rating: 1068
Best move: Nxa4