Chess puzzle (Advantage)
Opening: Ruy_Lopez, Ruy_Lopez_Exchange_Variation
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 bxc6 5. h3 Qf6 6. O-O Bc5 7. d3 d5 8. Bg5
Qe6 9. Re1 d4 10. Nbd2 Ne7 11. Nc4 O-O 12. Ncxe5 *
Position (FEN): r1b2rk1/2p1nppp/p1p1q3/2b1N1B1/3pP3/3P1N1P/PPP2PP1/R2QR1K1 b - - 0 12
Black to move.
Themes:  Opening  
Puzzle rating: 1234
Best move: f6