<P> Each bull has a unique name and number used to help identify it . A sufficient number of bulls, each judged to be of good strength, health, agility, and age, are selected to perform . The rider and bull are matched randomly before the competition, although starting in 2008, some ranked riders are allowed to choose their own bulls from a bull draft for selected rounds in PBR events . </P> <P> A rider mounts a bull and grips a flat braided rope . After they secure a good grip on the rope, the rider nods to signal they are ready . The bucking chute (a small enclosure which opens from the side) is opened and the bull storms out into the arena . The rider must attempt to stay on the bull for at least eight seconds, while only touching the bull with their riding hand . The other hand must remain free for the duration of the ride . Originally, the rules required a 10 - second ride, but that was changed to the current eight seconds . </P> <P> The bull bucks, rears, kicks, spins, and twists in an effort to throw the rider off . This continues for a number of seconds until the rider bucks off or dismounts after completing the ride . A loud buzzer or whistle announces the completion of an eight - second ride . </P> <P> Throughout the ride, bullfighters, also popularly known as rodeo clowns, stay near the bull to aid the rider if necessary . When the ride ends, either intentionally or not, the bullfighters distract the bull to protect the rider from harm . </P>

What do they put on bulls to make them buck