Chess puzzle (Advantage)
Opening: Modern_Defense, Modern_Defense_Other_variations
Moves: 1. e4 g6 2. Nf3 Bg7 3. Be2 d5 4. e5 c5 5. c3 Nc6 6. d4 cxd4 7. cxd4 Bg4 8. Nc3
e6 9. O-O Nge7 10. Bg5 O-O 11. Qc1 Bxf3 12. Bxf3 Qb6 13. Be3 Nf5 14. Bg5 Ncxd4
15. Bg4 Rac8 16. Bf6 Nh6 17. Bxg7 Kxg7 18. Bd1 Rc6 19. Qd2 Rfc8 *
Position (FEN): 2r5/pp3pkp/1qr1p1pn/3pP3/3n4/2N5/PP1Q1PPP/R2B1RK1 w - - 4 20
White to move.
Themes:  Middlegame  
Puzzle rating: 1540
Best move: Na4