Rook and Pawn vs Queen and Pawn: The Adjacent-File Defence

When both sides have a pawn, the file relationship classifies the ending before anything else.

The classification. Positions with the pawns on the SAME file are almost all lost. Positions with the pawns on ADJACENT files can be held, but only while the weaker side's pawn sits on its starting square.

The defence. In Dedrle's 1925 position Black is on move and holds by transferring the king to g7: Kf8, then Kg7. From there the king shields the blockading rook, and the untouched f7 pawn protects e6 and g6.

The tempo is everything. The same position with White to move is a win. See the companion drill.

Trust the wall, but check the sacrifice. Your king in front of the white pawn usually disarms the queen sacrifice, but not always. The sacrifice still wins whenever the pawn ending left behind is winning for White, so count that ending before you relax. When the sacrifice fails, it fails for exactly this reason: the pawn ending it leaves behind is drawn. The blockade square follows the pawn, not habit: against a pawn on e5 the king belongs on e7. And if the white king ever reaches the seventh rank, the defence is almost always gone.

In this drill you defend. Spend the move on the king walk and the wall holds.