A kind of derby is a type of race or competition that involves a variety of different activities. The most common types of derbies are SOAPBOX, ROLLER, and Kentucky derbies. A SOAPBOX derby is a race in which participants build and race homemade cars down a hill. A ROLLER derby is a contact sport in which two teams of five members skate around an oval track and attempt to score points by passing the other team's players. The Kentucky Derby is a horse race held annually in Louisville, Kentucky, and is the oldest continuously held sporting event in the United States.