Roller Derby
Roller derby is a contact sport played by two teams of five members roller skating counter-clockwise around a track. Roller derby is played by approximately 1,250 amateur leagues worldwide, mostly inside the United States.
Game play consists of a series of short match-ups (jams) in which both teams designate a jammer (who wears a star on the helmet). The jammer scores points by lapping members of the opposing team. The teams attempt to hinder the opposing jammer while assisting their own jammer—in effect, playing both offense and defense simultaneously.
