<P> Bronc riding, either bareback bronc or saddle bronc competition, is a rodeo event that involves a rodeo participant riding on a horse (sometimes called a bronc or bronco), that attempts to throw or buck off the rider . Originally based on the necessary horse breaking skills of a working cowboy, the event is now a highly stylized competition that utilizes horses that often are specially bred for strength, agility, and bucking ability . It is recognized by the Professional Rodeo Cowboys Association (PRCA) and the International Professional Rodeo Association (IPRA). Two organizations that strongly promote the event in the United States are the World's Toughest Rodeo (WTR) and the Championship Roughstock Challenge (CRC). </P> <P> Each competitor climbs onto a horse, which is held in a small pipe or wooden enclosure called a bucking chute . When the rider is ready, the gate of the bucking chute is opened and the horse bursts out and begins to buck . The rider attempts to stay on the horse for eight seconds without touching the horse with his free hand . On the first jump out of the chute, the rider must "mark the horse out". This means he must have the heels of his boots in contact with the horse above the point of the shoulders before the horse's front legs hit the ground . A rider that manages to complete a ride is scored on a scale of 0 - 50 and the horse is also scored on a scale of 0 - 50 . Scores in the 80s are very good, and in the 90s, are exceptional . A horse who bucks in a spectacular and effective manner will score more points than a horse who bucks in a straight line with no significant changes of direction . </P>

What breed of horse is used for bronc riding