Sicilian Defense: Scheveningen Variation, Qc7, g4BETA

Often a strong move. White looks to immediately attack black's kingside and dominate in the center by kicking away the f6-knight. This move is often paired with Rg1 and white castling queenside.

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.