Chess puzzle (Advantage)
Opening: Sicilian_Defense, Sicilian_Defense_Marshall_Gambit
Moves: 1. e4 e6 2. d4 d5 3. Nc3 c5 4. exd5 exd5 5. dxc5 Be6 6. Bb5+ Nc6 7. Be3 Nf6 8.
Nf3 a6 9. Ba4 Be7 10. Ne5 Rc8 11. Bxc6+ bxc6 12. Bd4 Qa5 13. O-O Bxc5 14. Re1
O-O 15. Nf3 Qb6 *
Position (FEN): 2r2rk1/5ppp/pqp1bn2/2bp4/3B4/2N2N2/PPP2PPP/R2QR1K1 w - - 4 16
White to move.
Themes:  Middlegame  
Puzzle rating: 1590
Best move: Na4