Learn How to Promote: Underpromotion Fork
This chess endgame puzzle is all about recognizing when promotion is not the best promotion. A passed pawn is ready to advance, but the key idea is that promoting to a queen can miss a stronger tactical resource. In this position, a lesser promotion creates a decisive fork and wins material immediately. That is a classic underpromotion theme: choose the piece that gives the most forcing result, not the most obvious one.