Linked squares where king positions mirror each other.
Why it matters
In locked king and pawn endgames, each square your king stands on has exactly one square the enemy king must stand on to hold the position. Those pairs are corresponding squares, and the whole game becomes a matter of getting there second.
Opposition is the simplest case of it. Corresponding squares is what you use when the pawns are irregular and simple counting no longer tells you which way to walk.
See it on a board
e7 answers e5, d7 answers d5: every square has its partner. The moment Black cannot reach the matching square, the white king walks in.
Checked: the position really has the feature described.
How to play it
- Find the key squares your king is trying to reach.
- Work backwards: for each square you could stand on, name the square the defender must answer with.
- Walk to a square where the defender has two answers to cover and only one king.
At each level
The same idea, said the way it is taught at each age.
Queen · ages 8–11
Work out the pairs before you move: for every square your king could take, know which square the defender must take to answer it.
King · ages 10 and up
The winning attempt is always to reach a square with two corresponding answers. One king cannot be on two squares, and the position collapses.
What goes wrong
- Moving the king first and working out the correspondence afterwards.
- Assuming plain opposition rules apply when the pawn structure is asymmetric.
Questions people ask
- Do I need to memorise corresponding squares?
- No. You work them out at the board, starting from the key squares and going backwards. What you memorise is the method, not the squares.