Corresponding Squares
A theory of paired squares in king endgames where, if one king occupies its square, the other king must occupy its paired square to hold the position.
If the defending king fails to reach its corresponding square in time, the attacking king can break through, often deciding an otherwise balanced king-and-pawn ending.
Etymology
The English term is one of several competing names for the same idea — Wikipedia also lists “relative squares,” “sister squares,” and “coordinate squares.” The concept was formalised in a series of studies: an 1892 example by Charles Dealtry Lockock, an 1901 study by Lasker and Reichhelm, and a 1924 study by Grigoriev. The name that fixed the theory in the literature was French: the 1932 treatise L'opposition et cases conjuguées sont réconciliées (“Opposition and Sister Squares are Reconciled”) by Vitaly Halberstadt and Marcel Duchamp. No source consulted names an individual who coined the English phrase “corresponding squares.”
First documented: 1932 — L'opposition et cases conjuguées sont réconciliées, Vitaly Halberstadt & Marcel Duchamp (1932) — for the French naming of the theory
Translations
Translations for this term haven't been added yet.