Colle System, King's Indian Variation

The King's Indian Variation of the Colle System arises when White answers 1. d4 Nf6 2. Nf3 g6 with the modest 3. e3 and 4. Bd3, and Black completes a King's Indian arrangement with 3...Bg7 and 4...d6. White has not played c4, so the resemblance to the King's Indian lies only in Black's setup. White keeps a compact d4–e3 center and develops behind it, usually aiming for the e3–e4 advance once the pieces are in place. Because Black's d-pawn stands on d6 rather than d5, the familiar Colle structure never appears, and the bishop on g7 exerts steady pressure along the long diagonal toward d4.

The most frequent continuation is 5. O-O, ahead of 5. Nbd2, which prepares to support e4, and 5. c3, which shores up d4; engines also consider h3. Black typically castles and then claims a share of the center with ...e5 or ...c5, as in the King's Indian proper. Play is unforced and relies more on understanding than on memorized theory. Engines judge the position roughly balanced, while in Lichess games Black has scored somewhat better than White.