Whether it be a simple game or life-or-death stakes, some people not only don't mind losing, but handle said loss with grace and dignity. This speaks well of their character, especially if they were initially presented as antagonistic.
It could be because they are putting things into perspective, particularly sportsmanlike, or are just naturally mature and accept loss as a part of life.
A common application is to a villain who has been bested by the heroes willingly laying down their sword. Perhaps the villain is sufficiently well-intentioned or rational to quit fighting, or a Noble Demon who respects the heroes' strength. It might indicate a genuine camaraderie between them and their heroic nemesis. It might even cause them to join the hero's side.
