Saddle up ...or don't. Two very different rides
Bronc riding, is split into two sports: saddle bronc and bareback bronc. It incolves a cowboy riding a horse (bronco), that is hell bent on throwing (bucking, whatever!) the rider off him.
Its a product of the skills necessary in horse breaking (think... All the Pretty Horses, with Matt Damon. Sweaty from a day’s work, ladies). Okay. The event is now a highly stylized competition that uses horses specially bred for sheer agility, strength and bucking ability.
Each competitor climbs onto a horse, which is held in a small pipe 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 8 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 shoulders before the horse's front legs touch back to the ground.
The cowboy climbs onto the horse, held in a narrow pipe enclosure called a bucking chute. When the rider is ready, he’ll nod to the gate. The chute gate opens and (all hell breaks loose) the horse bursts out in a buck. The rider’s got to stay on him for 8 seconds without touching the horse (whatsoever) with his free hand. The first jump out of the chute is when the rider ‘marks the horse out’, meaning: the heels of his boots must be in contact with the horse above the shoulders before the horse's front legs touch back to the dirt.
Just as in bull riding, if the cowboy makes the 8 seconds the judges score him (as the rider) on a scale of 0-50 and also score the bronc on a scale of 0-50. Scores in the 80s are really good; the 90s are exceptional. Horses that buck with a purpose (in a spectacular and effective manner) score more points than a horses bucking in a straight line with no real changes of direction.
In saddle bronc, the cowboy uses a specialized saddle with free swinging stirrups and no horn. The saddle bronc rider grips a simple rein braided from cotton or polyester, attached to a leather halter worn by the horse. The rider lifts on the rein and shoots to find a rhythm with the horse by spurring forwards and backwards with his boots.
Bareback bronc riders don’t use a saddle or rein, but use one hand to grip the handle of a surcingle style rigging on the horse. The rider leans back against the bucking horse and spurs vertically with his legs, in rhythm (ideally of course) with the motion of the horse.
Bucking horses are usually geldings, which are male and because bucking horses usually travel in close quarters and housed in a herd setting, geldings are generally less disruptive and more prone to get along with one another because a geldings are castrated males. Mares are also used though, and while a mixed herd of mares and geldings can mean more disruptions, they can be kept together without great difficulties. Stallions are less common, because they can be disruptive in a herd and aren’t afraid to fight if there mares around.
Modern broncs are not truly considered a feral horse. Most bucking stock are specifically bred for use in rodeos, with horses having exceptional bucking ability fetching a high price. Most grow up in natural, semi-wild conditions on open ranges, but also have to be gentled and tamed to be managed from the ground, safely loaded into trailers, vaccinated and wormed, and in and out of bucking chutes.