Normal Variation

With 4. e4 White takes the central space the King's Indian deliberately concedes, setting up pawns on c4, d4 and e4 before Black has committed the d-pawn. It is the most direct reply to the fianchetto and the junction from which the Classical, Sämisch, Four Pawns and Averbakh systems all branch. Engines give White a slight edge, and White scores a little better than Black in online play, though decisive results dominate and draws are uncommon.

The standard reply, chosen in roughly seven games out of ten, is 4...d6. The pawn rules out e5 hitting the f6-knight, clears the c8-bishop's diagonal and serves as the support for the later central strikes ...e5 or ...c5. White then picks a system on move 5. The line 5. Nf3, catalogued here as Rare Defenses, usually heads for the Classical main line with 5...O-O 6. Be2 e5 7. O-O. The Standard Development label covers 5. Be2, which keeps options such as Bg5 or Be3 in reserve, while the Deferred Fianchetto, 5. g3, places the king's bishop on g2 behind an already established e4-pawn. Sharper approaches such as 5. f3 and 5. f4 are treated under their own names.

About a quarter of players castle first with 4...O-O. This invites 5. e5, but the knight has e8 available; the tempting 5...Nh5?? runs into 6. g4, trapping it. After 5...Ne8 play can continue 6. f4 d6 7. Nf3, giving White a large but exposed pawn front that Black targets with pieces and pawn breaks. In most games, however, White answers with the developing 5. Nf3, and 5...d6 returns to the main positions.

Other fourth moves are marginal. 4...c6 is rarely seen, and 4...d5 simply drops a pawn, because the c4- and e4-pawns both bear on d5; a player intending the Grünfeld Defense has to choose 3...d5 before e4 is played. The King's Knight Variation refers to the 1. d4 Nf6 2. Nf3 g6 3. c4 move order, which can arrive at the same structures while sidestepping some of White's alternatives.