King's Indian: 4.Nf3 O-O 5.g3

King's Indian: 4.Nf3 O-O 5.g3

Definition

“King’s Indian: 4.Nf3 O-O 5.g3” is the Fianchetto Variation of the King’s Indian Defence (KID). The full move-order usually runs: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 O-O 5.g3. White postpones the customary pawn advance e2-e4 and instead develops the king’s bishop on the long diagonal (f1-a6). In ECO it belongs to codes E60–E62.

Typical Move Order

The basic sequence can be replayed here:

Transpositions are common. For example, the line can arise from an English Opening (1.c4) or a Catalan set-up (playing g3 before d4).

Strategic Ideas

• White’s Concept
  • Solid king safety through kingside fianchetto (Bg2).
  • Control of the central dark squares e5 and d4, restraining Black’s …e5 break.
  • Flexible pawn structure: White can choose c4-c5, b2-b4 and sometimes e2-e4 later.
• Black’s Concept
  • Maintain typical KID tension and eventually strike with …e5 or …c5.
  • Exploit the fact that White’s light-squared bishop is no longer on c4/f1 to attack the queenside light squares after …a6 and …b5.
  • Sometimes transpose to Grünfeld-type centres with …d5 if White plays d4-d5.

Key Plans & Structures

1. Panno Plan (…Nc6, …a6, …Rb8, …b5) – Black expands on the queenside and builds pressure on the long diagonal a1-h8.
2. Classical Central Break – …d6, …e5 followed by …Re8 and …e4 create kingside attacking chances.
3. “Hedgehog” Set-up for White – White keeps pawns on a2, b2, d4 and often plays a4, Rb1, b4 at the right moment.
4. End-game Edge – In many simplified positions the Bg2 vs Bg7 end-game slightly favours White because the g2-bishop bites on Black’s queenside pawns.

Historical & Theoretical Significance

Once considered a “King’s Indian nightmare”, the Fianchetto Variation was adopted by positional greats such as Tigran Petrosian and Ulf Andersson to neutralise Black’s dynamic play. The line surged in the 1980s when Garry Kasparov began facing it regularly; later, Vladimir Kramnik and Boris Gelfand made it a main weapon, proving that even aggressive KID specialists must possess deep positional knowledge to meet it.

Illustrative Games

• Petrosian – Portisch, Candidates 1974 – A textbook demonstration of queenside expansion with b4-b5.
• Kramnik – Kasparov, Linares 1994 – Kramnik squeezes with the “Hedgehog” and wins a superior end-game.
• Anand – Topalov, Wijk aan Zee 2006 – Shows Black’s modern Panno Plan leading to dynamic equality.

Enthusiasts may replay Kramnik’s model game here:

Interesting Facts & Anecdotes

• Garry Kasparov scored five consecutive wins with Black against the line in the late 1980s, reviving Black’s confidence by sharpening the Panno Variation.
• The Fianchetto Variation is one of the rare KID systems where opposite-side castling almost never occurs; both sides prioritise structural manoeuvring over direct mating attacks.
• Because the pawn chain usually remains un-fixed, engines often evaluate positions as “0.00” long before humans understand who is better—an example of modern engine/human interpretive gaps.

Practical Tips

• For White: Do not hurry with e2-e4; first restrict …e5. Queenside space (b4) is your long-term asset.
• For Black: Choose a clear plan early—either the central break …e5 or the Panno Plan—not a hybrid of both.
• Move-order traps: Playing 5…d6 6.Bg2 Nc6 7.O-O a6 8.d5? allows 8…Na5! hitting c4.

Summary

The sequence 4.Nf3 O-O 5.g3 is a positional antidote to the King’s Indian, emphasising long-term pressure over immediate confrontation. Its rich strategic content has kept it at the forefront of grandmaster practice for over half a century, making it essential study for both KID enthusiasts and those seeking a sound, flexible system as White.