Square of the Pawn: chess endgame

Check whether the king can catch an unsupported pawn.

For an unobstructed, unsupported pawn, imagine the square from its current square to promotion. Whether the king can enter that square on its next move helps determine if it can catch the pawn. Adjust for whose turn it is, a starting pawn’s two-square move and any blocked route.

• Count the pawn’s moves to promotion.
• Account for whose move it is.
• Check blockers, supporting pieces and the initial two-square advance.