Chess puzzle (Advantage)
Opening: Queens_Pawn_Game, Queens_Pawn_Game_Other_variations
Moves: 1. d4 d6 2. e3 d5 3. Nf3 Nc6 4. Nc3 Nb4 5. a3 Nd3+ 6. Kd2 *
Position (FEN): r1bqkbnr/ppp1pppp/8/3p4/3P4/P1NnPN2/1PPK1PPP/R1BQ1B1R b kq - 2 6
Black to move.
Themes:  Opening  
Puzzle rating: 1080
Best move: Nxf2