Bucking broncos buck primarily because they’re born with the instinct to do it. About 40 percent of professional rodeo bucking horses ended up in the sport simply because they kept throwing every rider who tried to sit on them. The rest come from carefully designed breeding programs that select for athleticism, power, and that explosive desire to get a rider off their back. The flank strap, spurring, and arena atmosphere all play supporting roles, but the foundation is always the horse itself.
Genetics Are the Biggest Factor
Bucking is a natural defensive behavior in horses. When something lands on a horse’s back that it doesn’t want there, its instinct is to arch its spine, drop its head, and kick its hind legs skyward to shake the threat loose. Most domestic horses have had this tendency bred out of them over centuries of selective breeding for calm, rideable temperaments. Bucking horses are the opposite: they’re selectively bred to keep that raw instinct intact and amplify it.
Ike Sankey of Sankey Rodeo Company, a former national finals rider, launched one of the first serious bucking horse breeding programs in the mid-1980s. His foundation sire, a stallion named Custer, proved the concept dramatically. Sankey reports that 85 percent of colts born from Custer’s bloodline grow up to become successful bucking horses. At the 1996 National Finals Rodeo, nearly 30 of the competing bucking horses were sons, daughters, or grandchildren of Custer. Among his famous descendants are Bobby Joe Skoal, the 1991 through 1993 Saddle Bronc Horse of the Year, and Skitso Skoal, who took the same title in 1994.
Today, roughly 40 of the 60 Professional Rodeo Cowboys Association stock contractors operate some kind of breeding program. These “Born to Buck” programs treat bucking horse genetics with the same seriousness that Thoroughbred breeders bring to racehorses. As Sankey put it, racing people have spent enormous sums trying to breed faster horses, while the general horse industry spent generations trying to breed the buck out of them. Bucking horse breeders simply reversed that selection pressure.
Not every bucking horse comes from a planned breeding program, though. A horse named Classic Velvet was originally bred as a team roping horse from racing Quarter Horse bloodlines. He just turned out to prefer bucking over anything else. Khadafy Skoal, another champion, was a registered Quarter Horse whose temperament made him better suited to throwing riders than carrying them. Some horses simply arrive at rodeo because no one could ride them.
What the Flank Strap Actually Does
The flank strap is the piece of equipment that generates the most confusion, and the most myths. It’s an adjustable leather strap, lined with sheepskin or neoprene, that wraps around the horse’s midsection in the flank area, roughly where a belt sits on a human waist. It does not wrap around or contact the horse’s genitals. Many bucking horses are mares, which makes the genital myth logistically impossible.
The strap works as a cue, not a source of pain. It creates a mild tickling sensation or light pressure that encourages the horse to kick its hind legs higher and with more extension. Think of it like a riding crop in dressage or leg pressure in any other equestrian sport: it’s an aid that enhances a behavior the animal already performs naturally. A horse with no desire to buck won’t suddenly become a bronco because someone strapped a piece of sheepskin around its belly.
While the horse stands in the chute, the strap hangs loosely. The moment the gate opens, it’s pulled snug. That tightening is the horse’s signal to kick up and out. Pulling it earlier would risk injuring both horse and rider, since the sudden burst of bucking inside a narrow metal chute could be dangerous. A quick-release mechanism allows the strap to be removed within seconds after the ride ends.
How the Rider Affects Bucking Intensity
The cowboy isn’t just a passenger trying to hang on. In saddle bronc riding, the rider moves his feet in a rhythmic spurring motion, sweeping from the horse’s neck toward the back of the saddle in time with the bronc’s jumps. This isn’t kicking with sharp spurs. PRCA rules prohibit sharp spurs entirely. The spurring motion creates a rhythmic stimulus on the horse’s shoulders and sides that encourages it to buck harder and with more consistent timing.
A good bronc rider and a good bucking horse create a kind of feedback loop. The horse bucks, the rider spurs at the peak of the jump, and that spur stroke prompts the horse to fire even harder on the next leap. Judges score both the rider and the horse, so a more explosive horse earns more points for everyone involved. Horses that buck with power, height, and unpredictable direction are the most valuable athletes in the sport.
How Young Prospects Are Developed
Even horses bred specifically to buck need some development before they compete professionally. Stock contractors typically give young horses their first opportunity to buck shortly after weaning, just to see what they’ve got. The goal at this stage is pure evaluation: does the animal show natural athleticism, explosive power, and genuine desire to get something off its back?
In bull programs (which use similar methods), trainers often use weighted dummies rather than live riders on young animals. The dummy is centered carefully on the animal’s back with evenly distributed weight and secured tightly enough that it won’t roll to one side during a buck. Trainer Bloyd keeps these early practice sessions extremely short, typically one to three seconds. The goal is to let the young animal “win” by bucking the dummy off quickly, building confidence. The animal learns that bucking works, which reinforces the behavior. Young prospects are never asked to buck for the full eight seconds that professional competition requires.
Over time, animals that show promise move through progressively more competitive settings. Horses that don’t show interest in bucking are sold as saddle horses or for other purposes. There’s no way to force a reluctant animal into becoming a successful bucking horse, because the behavior has to come from the animal’s own drive.
Equipment and Welfare Rules
Professional rodeo operates under strict equipment regulations. All flank straps must be lined with fleece or neoprene for horses. No sharp objects are allowed in any cinch, saddle, girth, or flank strap. Spurs must be dull. These rules exist because the animals are extremely valuable, often worth tens of thousands of dollars, and their careers can span a decade or more. A horse that associates rodeo with pain or fear won’t perform consistently, so stock contractors have strong financial and practical incentives to keep their animals healthy, confident, and eager to perform.
Professional bucking horses typically compete only a handful of times per year. Between events, they live on large ranches with pasture access. Their working life involves far fewer hours of physical stress than most performance horses in disciplines like racing, eventing, or endurance riding.