Chess Opening Theory/1. d4/1...Nf6/2. c4/2...g6/3. Nc3/3...Bg7/4. e4/4...d6

= King's Indian Defence =

4...d6
The move d6 ensures that White can't kick the Black Knight with e5. It also prepares to play e5 or c5 at some possible point. White has a variety of choices here.

By far the most popular line is the Classical main line, 5. Nf3, which results in a race on opposite sides: White tries to break through on the queenside before Black's forces get to the White king.

In the aggressive Sämisch Variation (5. f3), White will normally castle queenside (although castling kingside can also occur) and attack along the h-file. Black, meanwhile, will try to open the b-file with the advance ...b7-b5.

The most megalomaniacal variation is the Four Pawns' Attack, which sets up a fourth pawn on the fourth rank (hence the name) and gains a lot of space. Black must react quickly to avoid getting crushed by White's center.

Then, there is the quirky variation arising after 5. h3(Makogonov), which stops a knight from getting into g4 while retaining the option of Nf3.

The most positional variation in the King's Indian is the Fianchetto Variation. In this variation, normally the position is more fluid. Black usually exchanges his e-pawn for White's d-pawn, resulting in a situation where Black tries to play on the queenside dark squares and against e4, while White lines his forces up against d6 and the kingside.

In all of these variations, very sharp play ensues, making it the favorite of players such as Kasparov, Fischer, and Bronstein.

Theory table
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'''1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6'''