Chess puzzle (Advantage)
Opening: French_Defense, French_Defense_Advance_Variation
Moves: 1. e4 e6 2. Nf3 d5 3. e5 c5 4. c3 Nc6 5. d4 Qb6 6. Be2 Nge7 7. O-O Nf5 8. Kh1
Be7 9. Ne1 cxd4 10. f4 dxc3 11. Nxc3 Ne3 12. Bxe3 Qxe3 13. Rf3 Qb6 14. Rb1 O-O
15. Rg3 Nd4 *
Position (FEN): r1b2rk1/pp2bppp/1q2p3/3pP3/3n1P2/2N3R1/PP2B1PP/1R1QN2K w - - 6 16
White to move.
Themes:  Opening  
Puzzle rating: 1503
Best move: Na4