Chess puzzle (Crushing)
Opening: French_Defense, French_Defense_Franco-Sicilian_Defense
Moves: 1. e4 e6 2. d4 c5 3. Bc4 cxd4 4. Qxd4 a6 5. Bf4 b5 6. Bd3 Bb7 7. f3 Nf6 8. Nd2
Nc6 9. Qc3 Bb4 10. Qb3 O-O 11. O-O-O Qe7 12. Ne2 *
Position (FEN): r4rk1/1b1pqppp/p1n1pn2/1p6/1b2PB2/1Q1B1P2/PPPNN1PP/2KR3R b - - 10 12
Black to move.
Themes:  Middlegame  
Puzzle rating: 1674
Best move: Na5