A00-A99

Effectively a Sicilian Defense played with an extra move for White. This provides a slight tempo advantage in one of the most theoretically rich opening systems.

A direct confrontation where White attempts to prove that the flank c4-pawn is superior to Black’s central e5-pawn. It results in tense, complex play.

Prioritizes rapid development and piece activity over early pawn pushes. White often uses the kingside fianchetto to undermine Black’s central space.

A very solid system emphasizing the dark-squared bishop's control. It is a reliable defensive-offensive setup used by many legendary positional players.

Combines kingside safety with queenside expansion. White uses the fianchettoed bishop to support a later pawn storm or pressure on Black’s queenside pieces.

Mimics the Closed Sicilian but with reversed colors. The game is usually slow-paced, focusing on long-term strategy rather than immediate tactical strikes.

The pinnacle of closed structures in the English Opening. Both sides typically attack on opposite wings, making for a strategic race for initiative.

A highly symmetrical and balanced setup. The game usually revolves around minute positional improvements and the struggle for a tiny space advantage.

A dense and sturdy development of all four knights. It leads to stable, long-lasting middle-games where structural integrity is the primary concern.

Adds a powerful kingside fianchetto to the four-knights setup. This increases White's pressure along the h1-a8 diagonal and is a very potent modern weapon.