Learn How to Win Material: Discovered Attack
This chess endgame is a classic example of a discovered attack turning into a decisive tactical gain. One active rook already dominates the seventh rank, while the opposing king is exposed and the defending rook is vulnerable on an open file. The key idea is to use a forcing check to drive the king into a worse square, then exploit the alignment of pieces so the attack on the defender becomes unavoidable. In positions like this, activity matters more than raw material.