Jacques Mieses (White) Puzzle: Fork — Knight Tactic

A knight fork is especially powerful in a chess endgame because a single tempo can reverse a material imbalance. Here, the knight finds a protected central outpost with check, attacking the opposing king while also targeting an undefended major piece. The check prevents the defender from saving that piece immediately. This is a tactical refutation of loose coordination: even an extra rook cannot help if it is left vulnerable to a forcing fork.