Sicilian Defense

The idea

1...c5 fights for the d4 square like 1...e5 does, but it breaks the symmetry. Black usually trades the c-pawn for White's d-pawn, which gives Black an extra central pawn and an open c-file for counterplay on the queenside.

The result is an unbalanced game. White gets a lead in development and more space, and Black gets long-term structural trumps, which gives both sides chances to play for a win.

Plans for White

The main choice is the Open Sicilian, 2.Nf3 and 3.d4, which opens the center and uses White's lead in development, often for a kingside attack. About 80% of master games that start 1.e4 c5 continue with 2.Nf3.

White can also keep the position closed with 2.Nc3 and 3.g3, the Closed Sicilian, or attack straight away with 2.Nc3 and 3.f4, the Grand Prix Attack.

Plans for Black

Use the open c-file and the extra central pawn. In the Open Sicilian, Black's play is usually on the queenside: ...a6, ...b5, a rook on c8, and sometimes an exchange sacrifice on c3.

Black is often a little behind in development, so watch the king and don't open the position before you're ready.

Watch out for

For Black, the Magnus Smith Trap. After 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bc4, the natural 6...g6? lets White play 7.Nxc6 bxc6 8.e5!. Taking with 8...dxe5?? loses the queen to 9.Bxf7+ Kxf7 10.Qxd8.

Also for Black, in the Dragon: after 5...g6 6.Be3, the knight jump 6...Ng4?? is met by 7.Bb5+, and White wins a piece. White's own danger in every Open Sicilian is underestimating Black's counterplay on the c-file.

History

Giulio Polerio analyzed the opening in a manuscript from 1594, and Gioachino Greco analyzed it in 1623. In the 20th century it became the most played and most analyzed opening at both club and master level.