Chess puzzle (Advantage)
Opening: Russian_Game, Russian_Game_Modern_Attack
Moves: 1. e4 e5 2. Nf3 Nf6 3. d4 Nxe4 4. dxe5 Nc5 5. Bc4 Ne6 6. Nc3 Be7 7. a3 Nc6 8.
b4 a6 9. Qd3 b5 10. Bb3 O-O 11. Nd5 Bb7 12. Nxe7+ Qxe7 13. Bg5 *
Position (FEN): r4rk1/1bppqppp/p1n1n3/1p2P1B1/1P6/PB1Q1N2/2P2PPP/R3K2R b KQ - 1 13
Black to move.
Themes:  Middlegame  
Puzzle rating: 1232
Best move: Nxg5