Chess puzzle (Advantage)
Opening: Sicilian_Defense, Sicilian_Defense_Lowenthal_Variation
Moves: 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nb5 Nf6 6. N1c3 a6 7. Na3 Bxa3 8.
bxa3 O-O 9. Bc4 Qa5 10. Bd2 Qxa3 11. Qe2 Nd4 12. Qd3 b5 13. Bb3 Nxb3 14. cxb3
Bb7 15. O-O b4 *
Position (FEN): r4rk1/1b1p1ppp/p4n2/4p3/1p2P3/qPNQ4/P2B1PPP/R4RK1 w - - 0 16
White to move.
Themes: Defensive Move Middlegame  
Puzzle rating: 1920
Best move: Na4