to show in a snaffle or bosal. Senior horses who age out of the junior horse divisions at age six must be shown in a curb. The rules have changed over the years to reduce the stress on young horses. Junior horse divisions at one time were limited to horses that were only 3 and, sometimes, 4 years old. Expansion to age five parallels the standards set by the FEI and in endurance competitions, recognizing that the physical and mental development of most young horses is not considered complete until that time. Further, though many western stock horse breeds are started under saddle at the age of two, they generally are not physically or mentally ready to be entered into any type of reining competition at that age and in some cases are prohibited from entering any performance class until at least years old. Both the NRHA and many breed associations offer snaffle bit futurities, usually for three-year-old horses, which pay very large purses. Reining competition Reining as a sport was first recognized by the American Quarter Horse Association (AQHA) in 1949, and later by the United States Equestrian Federation (USEF) in its western division and within a number of its breed divisions. The National Reining Horse Association (NRHA) was formed in 1966 in the United States, and developed a worldwide membership as well as standardized rules and patterns that significantly influenced other organizations, including the AQHA and USEF. The sport of reining became an FEI-recognized discipline in 2000, and FEI-sanctioned reining competitions are held across the world, including at the World Equestrian Games. In 2011, USA Reining was established to serve as the reining sport affiliate for the USEF and FEI competition structure in the United States. Individual divisions at a reining competition vary with the sanctioning organization. However, standard classes include those limited to junior or senior horses, to horses of a specific age (such as three-year-olds), classes for professional, "non-pro," or amateur riders (those who do not work with horses for pay), youth riders of various ages, adult riders over age 40 or 50, as well as open events for all competitors. Classes may also be limited by the experience level of the horse or the rider. National In individual nations where reining competitions are held, national organizations usually oversee the sport. Reining classes can be held at a stand-alone competition just for reiners, or as one