Fianchetto Variation

The Fianchetto Variation (ECO E15) has long been White's most popular answer to the Queen's Indian. With 4. g3 White prepares Bg2, posting a bishop on the h1-a8 diagonal to neutralize the one Black intends to place on b7 and to add pressure on d5 and e4 from the flank. The engine considers the position roughly balanced, and White scores somewhat better than Black in the database.

Black's main choice lies between two bishop moves. 4...Bb7, the Traditional Line, appears in about two-thirds of games. After 5. Bg2 Black can hit the center at once with 5...c5, the Sämisch Variation, where 6. d5 exd5 7. Nh4 is the Rubinstein Variation, with White declining an immediate recapture on d5. The calmer 4...Bb7 5. Bg2 Be7 6. O-O O-O permits the Kramnik Variation, 7. Re1. The Nimzowitsch Variation, 4...Ba6, targets c4 immediately, and since White's king's bishop is heading for g2, guarding the pawn with e3 fits the setup poorly; 5. b3 Bb4+ is the Check Variation. The rare 4...Bb4+ aims to trade Black's less useful dark-squared bishop but tends to leave a somewhat passive game.