A horse race is a competition between two or more horses, with humans riding on them. Horse races have been a popular form of entertainment throughout history, and are widely considered to be among the most thrilling spectator sports in the world. While different countries have slightly varying rules for horse racing, most of them follow similar fundamental principles. In addition to the equine participants, the sport relies on spectators who cheer on the riders and watch the action unfold from the grandstands or from the infield.

In addition to the screams and cheers of fans, there is the whirring sound of thousands of horses’ hooves pounding the dirt. The sport is also known for its many injuries, including those sustained by the jockeys, who often fall off their mounts and are forced to run through pain.

Horse racing is a dangerous sport, and its history is rife with bloodshed, scandal, and controversies. It is also a business that has been notoriously difficult to regulate and a major source of gambling. The sport is regulated by state laws and international treaties, but there are many loopholes that allow illegal activity to thrive.

The sport’s early days were marked by a “play or pay” agreement, where the owners provided the purse for the race and bettors paid to play. These wagers were recorded by disinterested parties who came to be called keepers of the match book. Newmarket in England was one of the first venues to establish a record of matches, and John Cheny’s An Historical List of All Horse-Matches Run (1729) became the foundation for subsequent books with varying titles.

As the pandemic hit in 2019, Thoroughbred racing found a new audience: Americans suddenly locked down in front of their television sets, watching cup stacking, cherry-pit spitting, and old World Series games on TVG, an all-racing channel included in many cable packages. The channel quickly became the most popular in the country.

But the resurgent popularity of racing brought renewed scrutiny to its use of performance-enhancing drugs, which animal welfare advocates believe are often abused by trainers who want their horses to win no matter the cost. The most common of these medications is furosemide, better known as Lasix, a powerful diuretic that is given to horses on race day. It is meant to prevent pulmonary bleeding, which hard running can cause in some horses.

Breeding 1,000-pound thoroughbreds for massive torsos, spindly legs, and fragile ankles is a recipe for breakdowns. The horse does not reach full maturity, with its bones firmly fused and growth plates closed, until around age 6, and it is hurled into intensive training at 18 months. Then it’s compelled, with a human perched on its back, to run at breakneck speeds that, in nature, would get them killed. The result is a lot of broken horses. And a few dead ones, too. Sometimes even the best-bred and trained horses can’t avoid injury. When that happens, a photo finish is declared, in which a photograph of the final stretch is studied by a panel of stewards to determine the winner.