For anyone who cares deeply about horse racing, The FirstSaturday in May is not a cryptic calendar reference, but the year’s most anticipated red-letter day. It’s the annual running of the Kentucky Derby, only the first of American racing’s Triple Crown but more storied than any other equine contest.

Directors John and Brad Hennegan set out the statistics at the start of their documentary, focused on the 2006 Derby. Of the 40,000 thoroughbred horses in the United States, 23,000 will make it onto a racetrack. Only 20 of them will bolt onto the track of Churchill Downs when the metal gates swing open on Derby day. The big stables, with as many as 200 horses, have the best shot at the crown. But many smaller outfits work and sweat over their best steeds, defying heavy odds in their bid for the Kentucky Derby.

The First Saturday in May is the story of six trainers, each dreaming of raising the glittering cup of victory should his horse be first across the finish line. They are a diverse if white-male lot, including a muggy-voiced Southerner, a fast-talking New Yorker and a man paralyzed from the waist down from MS. They are united in their love of racing. Success can bring great financial rewards, yet being part of the sport is as much a passion as a profession.

Horse racing was a sport of kings in many cultures and an air of aristocracy continues at the major American competitions. The men look sharp in bespoke suits and the women go for Southern belle dresses and big brimmed hats. Along with the people, the Hennegan brothers show us the animals, affectionate creatures with those whom they trust. Their trainers often treat the horses with the fondness of favorite house pets.

Moving at a snappy pace with solid cinematography and editing, The First Saturday in May follows horses and trainers through a series of preliminary races whose winners will compete in Louisville. The excitement of contests decided by a nose, literally, is captured on film in between interviews with trainers, their friends and families, grooms and other contributors who are normally out of the spotlight.

Impending tragedy is felt throughout the film. Most viewers will already know the ending. Barbaro won the 2006 Kentucky Derby but stumbled in the Preakness, breaking a leg. Barbaro was finally put down to the dismay of a public provided with ringside seats by the media. The sight of Barbaro’s sad eyes in the aftermath of his accident forms a heartbreaking coda to The First Saturday in May.