different weight to carry based on its ability. Besides the weight they carry, horses' performance can also be influenced by position relative to the inside barrier, gender, jockey, and training. Jump racing Jump (or jumps) racing in Great Britain and Ireland is known as National Hunt racing (although, confusingly, National Hunt racing also includes flat races taking place at jumps meetings; these are known as National Hunt flat races). Jump racing can be subdivided into steeplechasing and hurdling, according to the type and size of obstacles being jumped. The word "steeplechasing" can also refer collectively to any type of jump race in certain racing jurisdictions, particularly in the United States. Typically, horses progress to bigger obstacles and longer distances as they get older, so that a European jumps horse will tend to start in National Hunt flat races as a juvenile, move on to hurdling after a year or so, and then, if thought capable, move on to steeplechasing. Harness racing A type of racing where horses go around a track while pulling a sulky and a driver behind them. In this sport, Standardbreds are used. These horses are separated into two categories, trotters and pacers. Pacers move the legs on each side of their body in tandem, while trotters move their diagonal legs together. The latter are typically faster than the former due to the gaits used. Occasionally a horse will break their gait into an actual canter or gallop. This could cause the loss of a race or even a disqualification. Notable races include the Breeder's Crown series. Saddle trot racing Ridden trot races are more common in places such as Europe and New Zealand. These horses are trotters who race on the flat under saddle with a jockey on their backs. Endurance racing The length of an endurance race varies greatly. Some are very short, only ten miles, while other races can be up to one hundred miles. There are a few races that are even longer than one hundred miles and last multiple days. These different lengths of races are divided into five categories: pleasure rides (10–20 miles), non-competitive trail rides (21–27 miles), competitive trail rides (20–45 miles), progressive trail rides (25–60 miles), and endurance rides (40–100 miles in one day, up to in multiple days). Because each race is very long, trails of natural terrain are generally used. Contemporary organized endurance racing began in California