King's Indian Attack: what should Black play?

In the King's Indian Attack (ECO A07), Black faces a flexible setup where White has committed to a kingside fianchetto with g3 and Nf3. While the engine identifies g6 as the most precise continuation to neutralize White's pressure, the most frequent response in over 12 million recorded games is Nf6, played in 24.0% of encounters. These choices allow Black to maintain central influence while preparing for White's typical expansion on the kingside or in the center.

Strategic objectives for Black

The move g6 carries an engine evaluation of +0.14 and is selected in 1.8% of games. By adopting a symmetrical fianchetto, Black prepares to challenge the long diagonal and often follows the main line g6 d4 Bg7 Bg2 c6 c4. This approach limits the effectiveness of White's g2 and establishes a solid defensive structure. Alternatively, Nf6 remains the standard developmental choice, leading to lines such as Nf6 Bg2 c5 O-O Nc6 d4, where Black contests the d4 square immediately.

Development of the light-squared bishop

Black frequently chooses to develop the light-squared bishop outside the pawn chain before committing to a central structure. The move Bg4 is seen in 5.9% of games and carries an evaluation of +0.21. This move pressures the f3 and often leads to the sequence Bg4 Bg2 c6 O-O Nd7 h3. Similarly, c6 is a popular preparatory move, occurring in 11.7% of games, which supports the d5 pawn and keeps options open for the bishop's development.

Central tension and transposition

The move c5 is the second most popular choice, appearing in 15.0% of games with an evaluation of +0.21. This move often transposes into Sicilian-like structures if White plays an early d4, as seen in the line c5 Bg2 Nf6 O-O Nc6 d4. By occupying the c5 square, Black ensures active counterplay and prevents White from achieving an easy space advantage in the center.