patzer2: According to Fritz 8, the move 9. ..Qf4!, as played in this game, is a win for black against this main line variation in the Muzio Gambit. I put it to Fritz 8 and it found a decisive win for black after every reasonable white response: (-2.44) 10. Bxf4 Nf6 11. Be6 Qxf3 12. Rxf3 Be7
(-3.34) 10. g4 Qg6 11. Qxf4+
(-3.47) 10. Nc3 Nf6 11. Qxf4 Qxf4 12. Bxf4 d6 13. Bg5 Nd7 14. Bxf6 Nxf6
(-4.19) 10. Qb3+ Qe6 11. Qd3 Nf6 12. Bxf4 Na6 13. Be5 Bg7 14. Nc3
(-4.19) 10. Na3 Bh6 11. Bxf4 Bxf4 12. Qxf4 Qxf4 13. Rxf4+ Kg7
(-4.19) 10. Qb3+ Qe6 11. Qd3 Nf6 12. Bxf4 Na6 13. Be5 Bg7
If this assessment holds, then one of the most popular and frequently played lines in the Muzio gambit is a bust in favor of black after only nine moves. Yet, what I find even more amazing is that the move 9. Qf4! in this variation has been known since Showalter vs Taubenhaus, 1889 and was mostly ignored until this game.