Pro bull riders are compelled to compete for many reasons.
"The money is good," said Lee, whose total prize earnings in his three years on the circuit total roughly $275,000. "And then there's the support of the fans."
Bull riding has evolved into an important spectator sport, with fan clubs, Web sites, and groupies who follow parts of the tour. While not quite celebrities, top bull riders sign autographs, give luncheon speeches, and do public announcements for charities.
But it's not only the riders who are famous.
World's Most Famous Bulls
"There's this one bull, maybe the most famous bull that's ever beenLittle Yellow Jacket out of North Dakota. He was voted best bucking bull in 2002 and 2003 by the best riders on the tour. No bull has ever won that title two years in a row," Hedeman said.
Other bulls have also become legendary, like Canada's Calgary stampede bull Outlaw, which weighs 2,100 pounds (995 kilograms) and has horns 2.5 feet (76 centimeters) wide. He was ridden unsuccessfully 57 times until pro rider Justin Volz, from Charlie Lake, British Columbia, hung on for the required eight seconds in 2003 before getting off safely.
The goal of professional bull riders is to hold onto the bull with one hand for eight seconds. Some competitions feature several rides per day by the same rider on different bulls. Depending on the contest, up to four judges dish out a score for a rider based on his ability to ride a bull and on the bull's bucking performance. A perfect score is 100 points. Most professional riders score between the mid-70s and high 80s.
The largest wild card is always the bull.
"You never know what you're going to get," Lee said. "Some days the biggest and most dangerous bulls are mellow. Other days the smaller bulls, let's say 1,500 pounds (681 kilograms), are the most dangerous."
The U.S. professional rodeo circuit averages one or two deaths annually. Several more riders suffer serious spinal or brain injuries each year, according to the World Health Organization's Helmet Initiative. It is coordinated by the Center for Injury Control at the Rollins School of Public Health at Emory University in Atlanta, Georgia.
Professional riders choose whether to wear helmets or not. Lee wore a helmet when he banged heads with Chili and thinks it may have saved his life.
This year Professional Bull Riders, Inc., is sponsoring more than a hundred competitions attracting at least 800 riders. Events are scattered across the U.S., Brazil, Canada, and Australia. Professional bull riding is growing into an international sport, with Russia, Sweden, and Japan all holding events as well.
"I love it. It's hard to imagine doing anything else for a living," Lee said. "Head injury or not, this is the greatest sport aliveand I live for those eight seconds."
Watch Dangerous Jobs, Thursdays at 8 p.m. ET/9 p.m. PT in the United States, only on the National Geographic Channel.
Everest Snowboarder Vanishes on Second Try
Veteran Climber Mike Bearzi Said to Have Perished in Tibet
Reporter's Notebook: Is Volcano Boarding the Next Extreme Sport?
Ice Bikers Follow Frozen Trail of Gold Rush
German Team Wins Marathon Volvo Ocean Race
National Geographic Channel
Professional Bull Riders
Professional Cowboy Association
The University of Calgary: Faculty of Kinesiology: Dale Butterwick