Semi-Tarrasch Defense, Pillsbury Variation

The Pillsbury Variation is White's most popular answer to the Semi-Tarrasch. White does not clarify the center with 5. cxd5. Instead, 5. Bg5 develops the bishop and pins the knight on f6, the piece that would recapture on d5. This raises the pressure on d5 and keeps the central tension, so Black, who is to move, has to decide how the c- and d-pawns will be resolved. The capture 5...cxd4 and the developing 5...Be7 are nearly equal in popularity. 5...Nc6 is a less common third choice, and the engine also rates 5...dxc4 among the best options.

The captures change the pawn structure at once. 5...Be7 instead breaks the pin and accepts a position where White still has the choice of exchanges. The engine considers the position roughly balanced, with a very slight lean toward Black. In practice the results are close: White scores marginally better over a large body of online games, and draws are rare.