THERE ARE two types of underdogs, divided into circles that are rarely concentric. More often than not, they are diametrically opposed. The first is the underdog in the classical sense: Buster Douglas, Milan High, the Americans in 1980, individuals or teams who, for one small sample of time, harnessed the power of energy and circumstance to orchestrate a performance that transcended their physical abilities, proving not that they belonged, but that belonging itself is an act subject to the same laws of chance as all other human endeavors. They came from nowhere, and then they returned there, a fleeting pit stop in between.