King's Indian Attack: Sicilian Variation: what to play after c5?

In the King's Indian Attack: Sicilian Variation (ECO A07), White's primary and most principled continuation is Bg2. The move completes the kingside fianchetto, readies the king for castling, and controls the long diagonal, yielding a slight engine evaluation of +0.14. Across 3,496,409 recorded games in this position, Bg2 represents the vast consensus, appearing in 94.5% of encounters with a 55.7% scoring rate for White.

Strategic Objectives of the Fianchetto

By developing the bishop via Bg2, White continues standard King's Indian Attack setup schemes without committing central pawns prematurely. The piece on g2 applies indirect pressure down the h1-a8 diagonal toward Black's queenside and contests key dark squares. An illustrative engine continuation demonstrates this fluid central development: Bg2 e6 O-O Nf6 c4 d4, where Black claims space with the d-pawn while White prepares central counterplay.

Alternative Central Approaches

Players seeking an immediate clash in the center occasionally opt for d4 or c4. The central thrust d4 is chosen in 3.0% of recorded games (106K recorded) and holds an even engine evaluation of +0.00, scoring 52.8% for White along the sample line d4 cxd4 Bg2 Nf6 O-O h6. Meanwhile, c4 appears in 2.0% of recorded games (70K recorded), carrying an evaluation of -0.13 and a 57.6% score for White, frequently continuing c4 d4 Bg2 Nf6 O-O Nc6.

Sidelines and Slower Setups

Rare alternatives such as c3 and a3 transpose the game into quieter waters but assess slightly in Black's favor. The move c3 accounts for 0.5% of games (16K recorded) with an evaluation of -0.19 and a 49.5% White score, illustrated by c3 Nc6 d4 cxd4 cxd4 Bf5. The prophylactic flank step a3 evaluates at -0.27 and leads into a3 g6 c3 Bg7 d4 cxd4, though neither deviation rivals the popularity or theoretical standing of Bg2.