Classical Variation, Swiss Variation

The Swiss Variation, 1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. Bd3, meets the attack on e4 by defending the pawn with a piece. It does not close the center with 4. e5 or pin the knight with 4. Bg5. The bishop takes its natural attacking diagonal toward h7, but it stands in front of the d-pawn and cuts the queen's line of defense to d4. That gives Black a clear target. It is one of the less common fourth moves in the Classical complex.

The two main replies are played about equally often. With 4...c5, Black strikes at d4 at once, exploiting the blocked d-file, and this move has given Black the better results in online play. 4...dxe4 gives up the center to trade pieces on e4. Here White scores somewhat better. A third option is 4...Bb4, which pins the c3-knight in Winawer fashion and increases the pressure on e4. Engines also consider 4...Nxe4. Overall results are close to even, and the engine rates the position as roughly balanced.