Frank Marshall (Black) Puzzle: Fork — Endgame Tactics

A fork is especially powerful in a chess endgame because every active piece and loose defender matters more. Here, Black’s knight finds a forcing check that attacks the king while creating a second threat against an undefended bishop. The check denies White the time needed to reorganize or save the vulnerable piece. This is a classic winning combination: use tempo to turn a strong outpost into a tactical weapon and convert activity into material.