Chess puzzle (Advantage)
Opening: Philidor_Defense, Philidor_Defense_Other_variations
Moves: 1. e4 e5 2. Nf3 d6 3. Bc4 Bg4 4. O-O Nc6 5. Nc3 Nd4 6. Be2 Qf6 *
Position (FEN): r3kbnr/ppp2ppp/3p1q2/4p3/3nP1b1/2N2N2/PPPPBPPP/R1BQ1RK1 w kq - 8 7
White to move.
Themes:  Opening  
Puzzle rating: 1981
Best move: Nxd4