Sozin Attack, Leonhardt Variation

The Leonhardt Variation is the Sozin Attack with Black's queen's knight already on c6. The position comes from the Classical Sicilian move order given here, 5...d6 6. Bc4 e6, and is also reached from the Scheveningen when Black answers 6. Bc4 with 6...Nc6. Compared with the ...a6 and ...Be7 lines, the knight increases pressure on d4 and keeps open the idea of ...Na5 against the bishop. That gives White reasons to retreat the bishop to b3 early or to exchange on c6. In the Classical order, 6...g6 instead of 6...e6 runs into the Magnus Smith trap.

The most frequent continuation is 7. O-O. 7. Be3 is the Main Line, after which both sides usually develop their dark-squared bishops. White then chooses between kingside castling and the Velimirović plan with Qe2 and O-O-O. The Fischer Variation, 7. Bb3 Be7 8. Be3 O-O 9. f4, prepares the f-pawn advance against e6. The immediate exchange 7. Nxc6 releases the central tension and has given Black good results. The engine rates the position as roughly balanced, and online results are evenly split.