Chess puzzle (Advantage)
Opening: Vienna_Game, Vienna_Game_Max_Lange_Defense
Moves: 1. e4 e5 2. Nc3 Nc6 3. Bc4 d6 4. Nf3 Nh6 5. d3 Be7 6. Nd5 O-O 7. Bg5 *
Position (FEN): r1bq1rk1/ppp1bppp/2np3n/3Np1B1/2B1P3/3P1N2/PPP2PPP/R2QK2R b KQ - 4 7
Black to move.
Themes:  Opening  
Puzzle rating: 789
Best move: Bxg5