ChessRanger
Endgame

Key square

A square whose control decides a king-and-pawn ending.

In pawn endings, certain squares are 'key': if your king reaches one, the pawn promotes and you win; if the defender holds them, it's a draw. For a pawn on the fifth rank or beyond, the key squares sit two ranks ahead of it.

The whole fight in many king-and-pawn endings is a race for the key squares, usually decided by the opposition.

Why it matters

Knowing the key squares turns 'push and hope' into precise technique — you know exactly which squares your king must reach to win.

The mistake everyone makes

Shoving the pawn instead of first walking the king to a key square, letting the defender take the opposition and draw.

Related terms

Opposition
Kings facing each other with one square between them; the side NOT to move usually holds the advantage.
Corresponding squares
Pairs of squares in a locked pawn ending where each king must mirror the other to hold or win.
Triangulation
Losing a tempo with the king (taking three moves to reach a square two allow) to put the opponent in zugzwang.
Passed pawn
A pawn with no enemy pawns able to block or capture it on its way to promotion.

See Key square in your own games

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