Schiffler-Sokolsky Variation

The Schiffler-Sokolsky Variation arises after 1. b4 e6 2. Bb2 Nf6 3. b5 d5 4. e3. Once Black's knight on f6 blocks the long diagonal, capturing on b4 with the f8-bishop no longer drops the g7-pawn, so White pushes the pawn to b5. There it claims queenside space and takes c6 away from Black's queen's knight. Black answers by occupying the center with 3...d5, and 4. e3 is a quiet continuation: it adds support to d4 and opens a path for the f1-bishop. The resulting setup resembles a reversed Queen's Gambit or Colle structure, with White's dark-squared bishop already fianchettoed. The cost is that the b5-pawn can become a target later.

Black has a wide choice here. The most common move is 4...Be7, which completes kingside development. With 4...c5 Black takes more space in the center and creates the possibility of capturing en passant on b6. 4...c6 challenges the b5-pawn directly and is the engine's first choice, although White has scored somewhat better against it in practice. The engine rates the position as roughly balanced. In online games White wins slightly more often than Black, and draws are rare.