"The First Saturday in May" captures the excitement at Churchill Downs during the Kentucky Derby. (Truly Indie Films)

The Kentucky Derby and the other two legs of the Triple Crown series represent much of what's wrong with thoroughbred racing in America. Newly turned 3-year-olds are asked to run farther and carry more weight than they should, and the attrition rate is staggering.

"The First Saturday in May," a documentary about the 2006 Derby, doesn't dwell on those faults -- or fractured sesamoids and torn tendons -- but celebrates all that's right with "the greatest two minutes in sports." And despite the tragedy that followed star thoroughbred Barbaro's triumph in Louisville that year, the documentary is decidedly upbeat.

Filmmakers Brad and John Hennegan labored at New York racetracks before going on to successful careers in television and movie production. They lucked into great human-interest stories with their film, and also had the foresight and fortune to follow several stables that spring who became major players by winning key Derby preps.

Of the six trainers whose horses the Hennegans focused on, five made it to the Derby.

And what a collection of characters: Michael Matz, the Olympic equestrian and plane-crash hero; Kiaran McLaughlin, who trains for Dubai's royal family despite the onset of multiple sclerosis; Dan Hendricks, who was paralyzed in a dirt bike spill; Bob Holthus, the septuagenarian with the horse of a lifetime, and Dale Romans, the Kentucky hardboot with an outrageous brother-in-law at his side.

The Hennegans use quick cuts as they show their subjects' care and affection for their horses, lingering occasionally as Matz shows his young son how to pet Barbaro without scaring him, and as McLaughlin nuzzles the playful Jazil. The behind-the-scenes footage gives equal time to the trainers, jockeys, owners and unsung heroes such as assistant trainers, grooms and exercise riders.

Jeff Johnson / Universal Press Syndicate