Square Control

Piet 1 Piet ¹

Program in the Piet programming language, printing "Piet", by Thomas Schoch, February 26, 2006, see Obfuscated Programming – Piet, Piet was named after the Dutch painter Piet Mondrian, DM's Esoteric Programming Languages - Piet ↩︎

Square Control,
refers to which and how many pieces attack or defend a particular square, independently from its occupancy state. Squares diagonally controlled by a pawn are usually taboo for opponent pieces, but the stop and possible pawn push target square is not controlled by the pawn itself, and could be blocked. If the square under investigation is occupied, the question arises whether the piece is hanging (if controlled exclusively by the opponent side) or en prise, which is topic of SEE and quiescence search.

Contents

In Evaluation

Square control is considered in evaluating piece mobility and connectivity, controls of squares around the king are matter of king safety evaluation, and center control might be considered as evaluation term in the opening or middlegame. Control of stop and telestop squares of passers is another evaluation topic. Some programs calculate a square control balance as difference of the sums of reciprocal piece values of both sides, and further aggregate the controls over all squares, possibly already considering center, king areas and passed pawn front spans by a weight matrix.