Normal Variation, King's Knight Variation

The King's Knight Variation is the King's Indian Defense reached with White's king's knight developed before the c-pawn advances. The position after 1. d4 Nf6 2. Nf3 g6 3. c4 is the same as the one arising from 1. d4 Nf6 2. c4 g6 3. Nf3, one of White's three principal third moves against the King's Indian, alongside 3. Nc3 and 3. g3. Material is level, Black is to move, and engines rate the position as roughly balanced.

Committing the knight to f3 shapes the rest of the opening. The square is the natural home for the piece and adds control over d4 and e5, but it blocks the f-pawn. White therefore forgoes the f2-f3 of the Sämisch Variation and the f2-f4 of the Four Pawns Attack, the two most aggressive ways of meeting the King's Indian. Black, in turn, faces a narrower range of systems. White can still bring the queen's knight to c3 and push e4 for Classical-type structures, or fianchetto the king's bishop and keep the center more restrained.

The great majority of players continue with 3...Bg7. The main independent branch is the Fianchetto Variation, 4. g3 O-O 5. Bg2 d6 6. O-O, which has long been a standard choice among grandmasters and was associated above all with Viktor Korchnoi. With the bishop on g2 sheltering the white king, Black's customary kingside pawn storm has little prospect of success, so play revolves around the center and the queenside instead. One approach is 6...Nbd7, preparing ...e5 and often a later ...exd4 with piece play. Another is 6...Nc6 7. Nc3 a6 8. d5 Na5, in which the knight on the rim exerts pressure on c4, the point White's fianchetto leaves least protected.

The alternatives at move three are rare. 3...d5 strikes at the center at once and leads to the Neo-Grünfeld Defense with Nf3; the Grünfeld is a fully viable reply to 3. Nf3. 3...d6 delays the bishop's development while keeping Black's options open.

In online games the results are close, with White only marginally ahead, and draws occur in only about one game in twenty, reflecting the unbalanced middlegames typical of the King's Indian.