Ruy Lopez Exchange Variation Opera Mate Puzzle (Rated 831): Spot Mate in 2 — Back Rank Mate
This middlegame puzzle is a classic example of a back rank mating pattern, where the enemy king’s mobility is restricted and a rook invasion becomes decisive. White’s active rook and bishop coordinate to exploit the cramped black king position, turning a seemingly normal tactical sequence into a forced finish. The key idea is not material gain, but using forcing checks to overload the defender and remove the last escape square.