Chess puzzle (Advantage)
Opening: Russian_Game, Russian_Game_Damiano_Variation
Moves: 1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Qe7 5. Qxe4 d6 6. Qa4+ Bd7 7. Qb4 Bc6
8. Be2 Qxe5 9. f3 a5 10. Qc3 Qe6 11. Qd3 Na6 12. O-O *
Position (FEN): r3kb1r/1pp2ppp/n1bpq3/p7/8/3Q1P2/PPPPB1PP/RNB2RK1 b kq - 5 12
Black to move.
Themes:  Opening  
Puzzle rating: 1760
Best move: Nb4