Sicilian Defense: Scheveningen Variation, Classical VariationBETA

a6 combines the idea of the Scheveningen and Najdorf. This move stops Ndb5 and also prepares the typical queenside expansion with b5 and possibly b4.

The Scheveningen is a solid pawn structure, as it sets up a small pawn center that controls the important squares on the 5th rank. However, black has spent a lot of time moving pawns instead of developing pieces, and so white can and should launch a vicious attack in the center and on the kingside before black catches up. The critical tries from white include a fast g4-g5 (possibly with Rg1 and h4 included as well), doing the so-called Keres attack.