On the classic 1967 series The Prisoner, residents of The Village play the fictional sport of Kosho. What's Kosho? Grown men in bathrobes and helmets, beating the crap out of each other on trampolines.
Kosho appeared prominently in the episode "It's Your Funeral." According to Kosho rules, one opponent must knock the other into a four-by-eight foot tank of water. Upon successful dunking, the Kosho match is over. It sounds easy, but there are plenty of opportunities to shatter one's sternum.
You have Prisoner star and creator Patrick McGoohan to thank for the wonder that is Kosho. Why Kosho hasn't caught on 40 years later is beyond me. On the plus side, we still have five more episodes before Lost blows our minds with "Hurleyball."