Chess puzzle (Advantage)
Opening: London_System, London_System_Other_variations
Moves: 1. d4 Nf6 2. Bf4 g6 3. Nf3 Bg7 4. Nc3 O-O 5. e4 Nh5 6. Be3 a6 7. Bd3 b5 8. O-O
Bb7 9. a3 d6 10. b4 Nd7 11. Ne2 e6 12. c3 f5 13. exf5 exf5 14. Bg5 Ndf6 15. Nf4
Nxf4 16. Bxf4 Ne4 17. Rc1 g5 18. Bxe4 fxe4 19. Nxg5 *
Position (FEN): r2q1rk1/1bp3bp/p2p4/1p4N1/1P1PpB2/P1P5/5PPP/2RQ1RK1 b - - 0 19
Black to move.
Themes: Hanging Piece Middlegame  
Puzzle rating: 820
Best move: Rxf4