Pietrowsky Defense

The Pietrowsky Defense is Black's reply 5...Nc6 after 1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3. It is one of the rarer answers to the accepted gambit. The knight targets d4, the only central pawn White has left. It can later be supported by ...Bg4, which threatens to remove the f3-knight that defends that pawn. The cost is that the c-pawn is blocked, so the ...c6 and ...c5 setups used in other defenses are no longer available.

The most frequent reply is 6. Bb5, which pins the knight and blunts its pressure on the center. It is also White's best-scoring choice in practice. The developing moves 6. Bd3 and 6. Bc4 are the other common options, and 6. Bc4 gives Black the best results of the three. The engine also favors the quieter 6. a3, which prevents ...Nb4, and 6. Be3, which reinforces d4. It assesses the position as roughly balanced, with Black a pawn up. In online play White wins more often than Black.