Modern Variation, Schmid Variation

The Schmid Variation, 1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3 Nb6, has Black withdraw the knight from d5 before White plays c4. In most Alekhine lines the retreat to b6 comes only after White gains a tempo by attacking the knight with the c-pawn. Here Black makes the move voluntarily. White has not committed the c-pawn, so the queenside pawns stay flexible and the d5-square is no longer contested by the knight. It is one of the less common replies to 4. Nf3, well behind 4...Bg4, 4...dxe5 and 4...g6.

The most frequent answer is 5. exd6, which settles the central tension at once. 5. Bd3 keeps the e5-pawn and develops toward the kingside, and 5. Nc3 is a less common developing move. Engines rate 5. a4 most highly, ahead of 5. Nc3 and 5. Be3. They give White a slight edge. In online practice the results are nearly even, and Black scores marginally better than White.