Understanding the Sicilian Defence

How to choose and study chess openings
The Sicilian is the most commonly used defense against 1.e4.  The beginner can be confused by its complexity and several variations; therefore he could be tempted to look for ways to avoid it rather than to deeply study it.  That's a pity because understanding, studying and playing the Sicilian defence can give him a lot of fun and it's also a required step if one wants to become a strong chess player.
The purpose of this section is to provide a simple guide to understand the Sicilian, its ideas, the possible pawns structures and the plans; it will be easier then to choose your pet variations and to build up a Sicilian repertoire to extensively study and play.

Sections Index

Strategy after the d4 exchange

Importance of the d5 square

Black pawn structures

Guidelines for White

Guidelines for Black

The above diagram shows the Sicilian starting position. Black
controls the d4 square and so prevents White to occupy the center. The idea is the same of the King's Pawn opening (after 1.e4 e5) but with different consequences:
  1. the center is controlled by a side pawn and therefore the exchange in d4 is in favor of the Black pawn structure that remains with two central pawns against White's only one (instead in the King's Pawn opening Black controls d4 with a central pawn);
  2. Black pawn can't be directly attacked; so White doesn't have a second move that is both a developing and attacking one (as it happens instead in the King's Pawn opening with 2.Nf3);
  3. Black's Bishops are still blocked by pawns and that will initially delay the minor pieces development and the castling (in the King's Pawn opening the Black Bishop in f8 has already an open diagonal).
In the Open Sicilian White allows the d4 exchange with 1.e4 c5; 2.Nf3 d6 (or 2...Nc6 or 2...e6); 3.d4 cxd4; 4.Nxd4.  That is the main and most effective variation, that leads to a complex and uncompromising play, characterized by the dynamic balance between White's extra space and the best pawn structure of Black.  Obviously White is not forced to propose the d4 exchange and he can play in a different way.  The alternatives to the Open Sicilian are called Anti-Sicilian systems; some of them are perfectly playable although they create fewer problems to Black and do not provide the dynamic and rich continuations of the Open Sicilian.
You are advised to integrate the study of these sections with the analysis of games played with the Sicilian defense; those games can be downloaded from the  Chess opening Data Base.