Mate In 3 Puzzle (Rated 1104): Spot Mate in 3 — Back Rank Mate

This chess puzzle is a classic mating net built around a pinned defender and a vulnerable back rank. In the middlegame, Black’s heavy pieces coordinate to force the white king into a sequence of checks that cannot be met by normal defense. The key idea is not material gain, but forcing moves: each check restricts the king and removes escape squares until the final mating pattern appears. It’s a great example of how tactical pressure can override otherwise balanced material.