Traditional Variation

The Traditional Variation is the old main line of the Fianchetto Variation. Black answers 4. g3 with 4...Bb7, contesting the long diagonal, and follows with 5...Be7 to prepare kingside castling and keep ...Bb4+ in reserve, rather than attacking c4 with 4...Ba6. The position is roughly balanced according to the engine, and White scores slightly better in the database.

The overwhelming choice is 6. O-O, leading to the Classical Variation, where 6...O-O 7. Nc3 Ne4 8. Qc2 Nxc3 9. Qxc3 gives White more space against a sound black position; Black then seeks counterplay with 9...c5, the most common move, or 9...f5 or 9...Be4. Because this sequence tends toward draws, White has looked for ways to unbalance the game, such as the pawn sacrifice 6. O-O O-O 7. d5, which after 7...exd5 8. Nh4 aims to regain the pawn or bring the knight to f5, or 6. O-O O-O 7. Nc3 Ne4 8. Bd2, which protects the c3-knight and prepares d4-d5. The second main option, 6. Nc3, the Anti-Queen's Indian System, delays castling in favor of the central advances e2-e4 and d4-d5. The early 6. Nh4 is rarely played.