Passive Rook Defense: Holding Knight and Rook Pawns

Rook endgame theory mostly preaches activity. And then comes the exception that wins you half points with no work at all: against ROOK and KNIGHT pawns, the purely passive setup is a fortress.

The setup. Defending king ON the promotion square, stepping aside only to the corner on the pawn's short side when a check forces it (here a8, and never toward the center: 1...Kc8? loses to 2.Ka7), rook anywhere on the back rank. That's the whole defense. The attacker's king can't approach the pawn's promotion square without walking into checks or trades; the pawn alone can't evict two defenders.

Why only a/b/g/h pawns? Against central and bishop pawns the attacking king has room on BOTH sides of the pawn: he shelters on the far side and the passive rook runs out of useful checks (that's Philidor/Lucena territory). Knight and rook pawns leave too little space on the short side: the eviction maneuver doesn't fit on the board.

Practical value: enormous. When you're tired, low on clock, and a rook down a pawn, knowing that THIS pawn type allows the lazy defense (and the others don't) is the difference between a routine half point and a technical collapse.