Petrosian System

1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.a3

With 4.a3, White plays a quiet prophylactic move that takes away ...Bb4+ ideas and keeps development flexible. The position remains strategic and transpositional, rewarding patient play and good piece coordination.

ECO Code

E12-E19

Difficulty

Beginner-Intermediate

Style

Prophylactic/Positional

Main Idea

Limit ...Bb4+

Typical Plans

White: Flexible Development

g3 or Nc3

White often chooses between a fianchetto plan or quick central expansion with Nc3 and e4.

Black: Solid Setup

...Bb7, ...Be7, ...0-0

Black completes development and prepares ...d5 or ...c5 to challenge the center.

Endgame Trends

Space vs activity

Positions are often slightly better for White structurally, but Black's piece activity is reliable.

Quiet, Practical Approach

The Petrosian System is about reducing Black's options and outplaying them in a strategic middlegame.

Back to Queen's Indian Defense Anti-Queen's Indian