Chess puzzle (Advantage)
Opening: Queens_Pawn_Game, Queens_Pawn_Game_Accelerated_London_System
Moves: 1. d4 d5 2. Bf4 Bf5 3. e3 e6 4. Nd2 Nc6 5. c3 Qd7 6. Ngf3 O-O-O 7. Bb5 f6 8. a4
h5 9. h4 Nh6 10. a5 Ng4 11. b4 Bd6 *
Position (FEN): 2kr3r/pppq2p1/2nbpp2/PB1p1b1p/1P1P1BnP/2P1PN2/3N1PP1/R2QK2R w KQ - 1 12
White to move.
Themes:  Middlegame  
Puzzle rating: 2029
Best move: a6