Chess puzzle (Advantage)
Opening: Vienna_Game, Vienna_Game_Stanley_Variation
Moves: 1. e4 e5 2. Bc4 Nf6 3. Nc3 Bc5 4. Nf3 O-O 5. a3 h6 6. O-O d6 7. d3 Bg4 8. h3
Bh5 9. Be3 Bb6 10. Nd5 Nc6 11. Nxb6 axb6 12. Qe2 Nd4 13. Bxd4 exd4 14. Rac1 d5
15. exd5 Nxd5 16. Qe4 Bxf3 17. Qxf3 c6 18. Qe4 Qg5 19. Qxd4 *
Position (FEN): r4rk1/1p3pp1/1pp4p/3n2q1/2BQ4/P2P3P/1PP2PP1/2R2RK1 b - - 0 19
Black to move.
Themes:  Middlegame  
Puzzle rating: 1577
Best move: Nf4