A good documentary is one that can pull you in even when it's about a topic that doesn't interest you. I went to the track to watch the ponies on one occasion and even that might give an inflated impression of how little I care about horse racing.

Although I've visited record shops, seen a production of "Rent" and watched minor league baseball on numerous trips to Louisville, I've never even thought about visiting Churchill Downs.

Yet, "The First Saturday in May," a documentary about the 2006 Kentucky Derby, by writers and directors Brad and John Hennegan, kept me in my seat for more than 90 minutes as it followed the trails of six trainers and their horses, jockeys, owners and other team members, as they pursued their dream of reaching the derby.

Among others, there is no-nonsense New York Frank Amonte; there is Michael Matz and his wunderkind thoroughbred Barbaro; there s Dale Romans, who built his career from nothing other than the dream of the derby; and there is Dan Hendricks, who despite an injury that rendered him paralyzed from the chest down, has continued to work as a successful trainer.

Then, of course, there are the horses, and the film is as much Barbaro's story as anyone else's.

There are lots of fast-paced racing shots, lots of scene-setting shots showing the grand carnival that is derby day in Louisville. But what really makes "First Saturday in May" an engaging film is that these trainers, these jockeys, these grooms are really just regular guys. They're not always overpaid, prima donna, 22-year-old baseball or basketball players. They're people with kids and families who work hard and still seem more focused on the glory of the game than the riches it can bring (that's perhaps of more interest to the owners).

When one trainer doesn't reach the Derby, we feel for him. When another clinches a spot at the gate, we celebrate with him because we've seen what it's taken for him to get there.

While "First Saturday in May" is ostensibly about horse racing and the Kentucky Derby, it succeeds because underneath, it's a story of humanity (and equinity, if that's a word!).

Best of all, the filmmakers understand the pressures that racing puts on horses and donate a portion of the proceeds from the film to the Grayson-Jockey Club Research Foundation, which funds equine research.