Chess Opening Theory/1. d4/1...Nf6/2. c4/2...g6

King's Indian defence
	a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
	Position in Forsyth-Edwards Notation (FEN) rnbqkb1r/pppppp1p/5np1/8/2PP4/8/PP2PPPP/RNBQKBNR
	Moves: 1. d4 Nf6 2. c4 g6
	ECO code: E60-E99
	Parent: Indian defence → 2. c4

2...g6 · King's Indian defence

With 2...g6, Black intends to fianchetto their dark square bishop with ...Bg7. Because ...g6 weakens the f6 and h6 dark squares on the king's side, the bishop is important to defend the king after Black castles. In addition, from g7 the bishop will exert pressure on the long diagonal and target White's centre.

3. Nc3 is the main move. This prepares to play e4. Usually, White employs a set-up with Be2, Nf3 and O-O and will attack on the queen's side. Black continues with 3...Bg7. Black usually attacks on the king's side, and looks for pawn breaks with ...e5 and...f5, or sometimes ...c5 and ...b5. The main side line is 3...d5, the Grünfeld defence, the main line of which involves trading the knights: 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3.

White has a few sidelines, though sometimes these are just changes in move order. One decision that makes a difference is where White would like to play their king's bishop. In the main line it develops to e2, but they may also choose to fianchetto it, in which case they may start with 3. g3 or 3. Nf3 Bg7 4. g3, the fianchetto variation. In these positions, White may avoid playing e4, which would inhibit their bishop's vision on the long diagonal.

Also to consider are the anti-Grünfeld lines. 3. f3, the Alekhine variation, supports playing e4 with a pawn instead of the knight. The idea is that if 3...d5 anyway, 4. cxd5 Nxd5 5. e4 and Black can't trade the knights and must play 5...Nb6. 3. d5, the advance variation, the idea being Black cannot play 3...d5 if White's pawn is already there.

Finally, 3. h4 is the Basman-Williams attack.

History

The Indian defences are named for their use by Indian chess masters in the 19th century, and were introduced to Europe especially though the games of John Cochrane against Kolkata chess masters Moheschunder Bannerjee and Saumchurn Guttack.

The king's Indian defence is the archetypal hypermodern opening and received renewed interest in the 1920s. The hypermodernists thought to control the centre with pieces at range, as opposed to the classical school of though which was to occupy the centre with one's pawns.

In the 20th century it grew in popularity and was favoured by many of the strongest players, including by World Champions Garry Kasparov^[1] and Bobby Fischer.^[2] Today it is seen as one of the most reputable ways for Black to meet d4 openings.

Tartakower defined 1. d4 Nf6 2. c4 g6 as the alt-Indisch (German: old Indian) (with ...d6 being played later. The "New" Indian was with 2...e6 and later ...b6).^[3] Nowadays "old Indian" usually refers to a set-up with 2...d6, playing for ...e5 without the idea of fianchettoing the king's bishop: 1. d4 Nf6 2. c4 d6 3. Nc3 Nbd7 4. e4 e5 5. Nf3 Be7. Lichess's opening book refers to this position as the West Indian, reserving the "king's" soubriquet until after White has moved, though this is atypical.

Theory table

1. d4 Nf6 2. c4 g6

	3	4	5	6	7
King's Indian defence	Nc3 Bg7	e4 d6	Nf3 O-O	Be2 e5	O-O c6	∞
Grünfeld defence	... d5	cxd5 Nxd5	e4 Nxc3	bxc3 Bg7		=
Anti-Grünfeld	f3 d5	cxd5 Nxd5	e4 Nb6			∞
	g3 Bg7	Bg2 O-O	Nc3 d6	Nf3		∞