King's Indian Defense, Petrosian Variation

The Petrosian Variation appears when White advances the d-pawn from d4 to d5 early and blocks Black's e5-pawn before castling. The coordinates d4, d5, and e5 name squares by file and rank. Castling is the special move that relocates the king and a rook together. The closed center reduces immediate exchanges and makes it harder for Black to activate every piece through central lines.

White's aim is not passivity but time to organize the pieces and restrain Black's f-pawn advance. A bishop on g5 can pressure the f6-knight, while the c3-knight and e4-pawn support the center. Black seeks alternative knight routes and prepares an f-pawn or c-pawn advance according to White's setup.

Closing the center grants space, meaning more room behind advanced pawns, but also fixes a target on d5. If White fails to develop, Black can use the c-pawn to attack the base of White's pawn chain, the group of pawns that protect one another diagonally, or reorganize for the f-pawn advance. The Mar del Plata reaches a similar center after White has castled and Black has developed the queenside knight.