Classical Variation

The Classical Variation arises after 1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 Nf6 5. Nf3 Bf5. Black brings the light-squared bishop outside the pawn chain at once and postpones ...c6, which elsewhere in the 3...Qa5 complex gives the queen a retreat square. The trade-off is speed of development against a queen with fewer escape routes. The queen on a5 pins the c3-knight while White's d-pawn stands on d4. Engines give White a slight edge, while online results are almost exactly even.

The most common reply, 6. Bd2, is also the engine's first choice. It breaks the pin, so a later knight move uncovers an attack on the queen. 6. Bd3 offers a trade of light-squared bishops and contests f5 directly. 6. Bc4 develops toward f7 and is the third most frequent choice. The engine also rates 6. Ne5 highly, using the knight to take up an active central post before Black completes development. Black usually follows up with ...e6 and ...c6, reaching a structure close to the main line, though the move order leaves White extra options in the meantime.