Chess puzzle (Advantage)
Opening: Queens_Pawn_Game, Queens_Pawn_Game_London_System
Moves: 1. d4 d5 2. Bf4 Nf6 3. Nf3 g6 4. Be5 Bg7 5. e3 O-O 6. Bd3 Nc6 7. Bf4 Bg4 8. h3
Bxf3 9. Qxf3 Re8 10. Nd2 e5 11. dxe5 Nxe5 12. Bxe5 Rxe5 13. Qf4 Nh5 14. Qg4 d4
15. Nc4 Rg5 16. Qf3 b5 17. Na5 dxe3 18. fxe3 Bxb2 19. Rd1 Rd5 *
Position (FEN): r2q2k1/p1p2p1p/6p1/Np1r3n/8/3BPQ1P/PbP3P1/3RK2R w K - 2 20
White to move.
Themes: Defensive Move Middlegame  Castling
Puzzle rating: 2344
Best move: O-O