Opposite Side Castling Puzzle (Rated 1585): Pin Tactics — Decisive Material Gain

This puzzle is a classic middlegame tactical refutation built around a pin and a vulnerable king position. White’s active pieces create pressure, but Black can exploit the exposed alignment of pieces and the loose bishop on c4. The key idea is to use forcing moves that win material while keeping White’s king from organizing counterplay. In practical terms, this is the kind of position where a tactical sequence turns a small imbalance into a decisive advantage.