Chess Openings Lab
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King's Indian Defense: Semi-Averbakh System

The Semi-Averbakh System is 5.Be2 O-O 6.Be3, posting the bishop on e3 while the g1 knight stays home. White wants a sturdy center and flexible development, while Black answers with ...Na6 and ...e5, a quick ...c5, or ...c6 with ...Ng4 to hit the bishop.

Moves
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Be3
ECO
E73
Engine
+0.58 · a slight edge for White (Stockfish 17.1, depth 20)
Played
334 games in our lichess sample
White scores
50.4%

Key ideas for both sides

White

  • Play Nf3 and castle; in the top engine line White meets ...e5 by taking with dxe5.
  • After ...c5 and d5, the engine finds e5 after ...b5, using the space to strike first.
  • Against ...Ng4, drop the bishop to d2 and close the center with d5 after ...e5.
  • The e2 bishop covers g4, so a black knight landing there can be exchanged for the bishop.

Black

  • ...Na6 is the top engine move, preparing ...e5 and keeping the queen free for ...Qe8.
  • ...c5 with ...e6 and ...b5 gives a sharp Benoni-type game against White's uncastled king.
  • ...c6 and ...Ng4 chase the e3 bishop before White has Nf3 to support it.
  • After d5 locks the center, aim for ...f5 once the f6 knight has moved.

Plans and pawn structure

This setup sits between the Averbakh and Classical systems. White delays Nf3, so the e3 bishop supports d4 without allowing ...Ng4 for free, since Be2 watches that square. Black's main choices are ...Na6 with ...e5, or a Benoni-style ...c5 and ...e6. If the center locks after ...c6 and ...e5, Black uses ...f5 while White plays on the queenside. If the center opens, the g7 bishop and pressure on d4 matter most.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.58: a slight edge for White. Its three top choices for Black:

  1. +0.58 6...Na6 7.Nf3 e5 8.O-O Qe8 9.dxe5
  2. +0.62 6...c5 7.d5 e6 8.Nf3 exd5 9.cxd5
  3. +0.70 6...c6 7.Nf3 Ng4 8.Bd2 e5 9.d5

Pawns, from White's side.

How it scores on lichess

334 rated lichess games reached this position; White scored 50.4%.

1600–199948.4%
2000 and up52.0%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

How to play against it

As Black, use the delay of Nf3 to play ...Na6 and ...e5, or strike with ...c5 at once. After ...c5 and d5, be ready for White's e5 thrust. As White, complete Nf3 and castle before choosing between d5 and dxe5, and keep the e3 bishop safe from ...Ng4.

Questions

What are the moves of the King's Indian Defense: Semi-Averbakh System?

The King's Indian Defense: Semi-Averbakh System starts 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Be3. Its ECO code is E73.

Is the King's Indian Defense: Semi-Averbakh System good for White?

Stockfish 17.1 rates the position +0.58 at depth 20, which is a slight edge for White. In 334 lichess games from our sample, White scored 50.4%. A solid, slightly offbeat choice for White players who like flexibility, and Black should answer actively rather than with slow setup moves.

What is the main idea of the King's Indian Defense: Semi-Averbakh System?

White develops Be2 and Be3 before Nf3, aiming for a solid center with the f-pawn still free. Black uses the time for ...Na6 and ...e5, a sharp ...c5, or ...Ng4 against the bishop.

What should Black play next?

The engine's first choice is Na6, with c5 and c6 close behind. ...Na6 supports ...e5 and keeps the c-pawn and queen free for later queenside play.

Updated October 2026. Sources and method.