Sicilian Defense: Najdorf Variation, English AttackBETA

g6 enters a Dragon setup, which combined with a6 is often called the "Dragondorf." This line is not great for black simply because the English attack in the Najdorf contains exactly the same moves as the Yugoslav attack in the Dragon, but a6 is a slow move in the Dragon (since a5 or b5 are often played in one move). By mixing plans, black gives white one extra move in what is already considered the most critical attempt to blow black off the board in the Dragon.

The English attack, starting after Be3, f3, Qd2, and O-O-O, leads to slower positions than the more active Bg5 Najdorf. White first plans to castle queenside before launching g4, h4, g5, h5, etc for a ferocious kingside attack. Black on the other hand gets stronger control of the center with e5, and more liberated pieces.