King's Knight Opening Puzzle (Rated 1466): Fork — Rook Double Attack

This middlegame position turns on a crushing fork. The winning idea combines a forcing capture on a key outpost, trades along the open file, and a rook that finally double-attacks the enemy king and a loose bishop. Forks against the king are decisive because the check steals a tempo: your opponent must answer it, and the second target falls next move. When your bishop pressures an enemy knight along a long diagonal, the ingredients for this tactical refutation are on the board.