Demolition Derby

Derbies frequently have few rules, with most regulation focusing on the cars' composition and not on the actual action on the track. Drivers are often required to be at least 16 years old. They are usually required to have seat belt and a helmet. An event begins with drivers lined up on a dirt oval with their tail lights facing each other. They begin in reverse and starting crashing into each other. Drivers are usually required to crash into another vehicle every 2 minutes or they are labeled as "sandbagging" and become disqualified. The last running car wins the event; in order to speed up the end of a particular event, some derbies will require the last two cars running to make all hits from that point forward head-to-head, making contact only with the front ends. An event typically takes about 20 minutes. Depending on the sanctioning body, it may be illegal for multiple cars to collaborate and gang up on opposing cars in a sandwich effort, and could result in disqualification for both parties that do so; the enforcement of this rule varies widely.
The demolition derby was originally designed to serve as an amusement while attendees bought food and beverage from track concessions. Motor Madness derbies were primarily for broadcast and needed to fit into a time frame. Live demolition derbies could last as long as possible. Motor Madness changed the rules from last car running to largest number of offensive hits in a time frame, and thereby helped prevent sandbagging, since sandbagging would result in a lower score.