A horse race is a contest of speed among horses ridden by jockeys or pulled by sulkies and their drivers. Whether they are flat or steeplechases, horse races have a long history and have been a popular form of public entertainment throughout the world. The basic concept of a horse race has changed little over the centuries; the winner is the first horse to cross the finish line. The sport has evolved into a complex spectacle with large fields of runners, sophisticated electronic monitoring equipment, and immense sums of money involved, but the horse race itself remains the same.
The horse is a prey animal and in the wild, it prefers to run as part of a herd or pack, to be near other horses for safety and protection. Winning a horse race requires speed and stamina, which horses are not naturally born with. In the past, horses were bred to meet specific requirements for racing. The oldest known traces of horse races are four-hitch chariot and mounted (bareback) races held during the Olympic Games in Ancient Greece over the period 700-40 bce. Organized racing began in Europe during the reign of Louis XIV (1643-1715) with a system of gambling on races.
In order to be eligible to race, a horse must have a pedigree that includes a sire and dam that are pure of the breed. In addition, most racing rules require a horse to have a particular body type and to be of a certain age in order to compete. Besides speed, the ability to make quick acceleration is important for winning. Some races are short, referred to as sprints, and are seen as tests of speed; other races are long and viewed as a test of stamina.
As the popularity of horse racing increased in the 19th century, more and more people began betting on it. During this time, betting lines for each horse were drawn on a board with different payouts depending on the odds. The highest odds are offered for horses that are expected to win the race, while the lowest odds are given to horses that are considered outsiders or have a difficult chance of winning.
Many horse races are decided by a photo finish, which occurs when two or more horses cross the finish line simultaneously and cannot be determined by the naked eye. The photo is studied by stewards to determine the winner. If there is no clear winner, the race is declared a dead heat.
Although the vast majority of horse races are won by a single horse, it is common for a race to be interrupted due to an injury to a competitor. Injured horses must be immediately withdrawn from the race and are not eligible to receive any payoffs. Injured horses are also at risk of re-injury if they try to come back into competition too soon. In order to reduce the number of injured horses, veterinary experts advise that they should be rested for at least six weeks after an injury.