Barbaro deserves his own film. Remember Barbaro? He was the beautiful, rich brown, seemingly preternatural American thoroughbred horse who won the 2006 Kentucky Derby by six and a half lengths—a margin larger than any Louisville victory since the 1946 Triple Crown winner—just two weeks before his hopeful run in the next leg of the Crown resulted in an injury that eventually, slowly, killed him.

Part of the mystery of horse racing is the elusiveness of the creatures themselves. Do they have good lives or bad lives? Do they want to race? Few of them rise to the level of public empathy, but Barbaro did. When brothers Brad and John Hennegan set out to follow six trainers and six horses on their journey toward the ultimate horse race (the Derby) in 2006, they had no idea that one of their animal stars would prove to be more of a draw than any of their human subjects. Now, the movie's publicity materials boast about "never-before-seen footage of a young Barbaro," and he, truly, is the highlight of the film.

But horse racing is a great subject in itself, characterized by tension between the seedy and the dignified, the rich and the poor, the Sunday bettor and the addict—and between silver-spoon trainers and salt-of-the-earth trainers, between guys looking to make a buck and a name and guys who lie right down with the horses on the hay in their stalls. In this movie, it's not always possible to tell who's who. The trainer who comes across as the kindest and gentlest is also the one working for a Dubai sheikh. One of the best characters is a hanger-on who carries $1,034 in his jeans pocket, plans to crack an $800 bottle of wine if his horse wins the Derby, and is always trying to talk somebody into taking out a short-term, high-interest loan from him. He's the son of one of the trainers, and he's in grade school.