Chess puzzle (Advantage)
Opening: Ruy_Lopez, Ruy_Lopez_Morphy_Defense
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Bc5 6. c3 b5 7. Bb3 d6 8. d4
exd4 9. cxd4 Bb6 10. Nc3 Bg4 11. Be3 Na5 12. e5 Nxb3 *
Position (FEN): r2qk2r/2p2ppp/pb1p1n2/1p2P3/3P2b1/1nN1BN2/PP3PPP/R2Q1RK1 w kq - 0 13
White to move.
Themes:  Middlegame  
Puzzle rating: 1781
Best move: exf6