King's Indian Attack
The fastest way to fianchetto the king's bishop and castle is the King's Indian Attack (KIA), the reverse of the King's Indian Defense. White just plays Nf3, g3, Bg2, and 0-0, before seeing how to proceed.
The KIA also refers to a plethora of systems for White involving pawns on d3, g3, and e4; knights on d2 and f3; a kingside fianchetto and kingside castling. This KIA setup can be used after 1.e4 against the Sicilian Defense, French Defense, Caro-Kann Defense, and many other popular openings for Black. White often plays for a kingside attack with Black trying to win on the queenside.
Starting Position
The King's Indian Attack, when referring to a specific opening, generally starts with either 1.Nf3 d5 2.g3 or 1.Nf3 Nf6 2.g3.
A kingside fianchetto with Nf3 is an idea in several other openings as well, most notably the French Defense variation 1.e4 e6 2.d3, but also in the Sicilian, Caro-Kann, and others.
Pros
- Flexible
- May lead to a kingside attack
- Not very theoretical
Cons
- Allows Black a strong center
- Gives Black many different options
- Does not put immediate pressure on Black
Variations
There are many variations of the KIA, but the main question regardless is Black's decision with the c-pawn: Play ...c6 to blunt the fianchettoed bishop's diagonal, or play ...c5 to gain extra queenside space? This choice also determines where Black's b8-knight will go: behind the c-pawn on c6 or to d7.
Oftentimes Black will play not only ...c5 but ...b5 and ...a5 and try to win on the queenside before White can break through on the kingside, as in the following possible move order.
Some specific early variations are below.
Yugoslav Attack (2...Nf6)
Whichever order Black plays the first two moves ...Nf6 and ...d5, it's the Yugoslav Variation. It's the most common way to meet Nf3 and g3 from White, both developing and beginning to claim the central space that White has foregone.
Keres Variation (2...Bg4)
The Keres Variation, named for GM Paul Keres, is mainly a move order subtlety where Black develops the c8-bishop as quickly as possible, to be followed up with ...Nd7 and ...c6.
Sicilian Variation (2...c5)
Black can also immediately announce the intention to claim as much space as possible with ...c5 on move two. It essentially creates a reverse King's Indian Defense and play often continues in that vein with something like 3.Bg2 Nc6 4.O-O e5 or 4...Nf6.
History
Like several hypermodern openings, the King's Indian Attack was first known to be played by Bonnerjee Mohishunder in his games with John Cochrane in Calcutta (Kolkata), India in the 1850s, but did not become more widely popular until the 1920s.
The heyday of the KIA was the 1960s when GMs Pal Benko and Bobby Fischer won regularly with it, as IM Jeremy Silman discusses here. Although now less popular at the GM level, it can be used when someone desperately needs a win as White, and remains a good option for more casual players.