PARK CITY, Utah (Hollywood Reporter) - A quietly captivating portrait of an unlikely character, “Buck” is as modest as its subject and wins viewers over just as easily.

Holding strong appeal in the nonfiction arena, the picture could be a hit for distribs who manage to book it into Middle-American markets where few documentaries fear to tread.

Buck Brannaman, who inspired “The Horse Whisperer,” proves as impressively gifted in reality as any fictionalized version could be -- and even, though his not-quite-handsome face would never compete with Robert Redford’s, possessed of an undeniable magnetism. A quiet man who almost seems to mind-meld with horses, he makes no secret of the belief that his training helps both horse and owner.

We follow Brannaman on the road, where he spends nine months of the year teaching four-day seminars in “colt starting” (as opposed to “breaking”), dispensing wisdom that sounds like common sense when it leaves his mouth but is -- as we learn from interviewers who have practiced more mechanical, control-based methods -- anything but. Brannaman gathers colt owners in a corral and shows, gesture by gesture, how a rider can become one with his mount instead of dominating him.

The master’s understanding of skittish young horses came at a price: We hear of the abusive upbringing that left him scarred (both mentally and physically), and as he speaks of it we both grasp his insight into horses whose fear prevents obedience and marvel at the unflappable empathy he has developed over the years.

That empathy is tested in a sequence near the end, where Brannaman is confronted by a truly dangerous animal. Though he himself manages to calm the stud, others can’t make his lessons stick; we see a man badly wounded and watch the sad aftermath, getting a rare glimpse of sternness from the trainer -- not toward the horse, but toward the woman he chides for trying to manage over a dozen studs herself.

After citing earlier trainers who directly inspired Brannaman, director Cindy Meehl ignores his contemporaries who share similar philosophies, making him look like something of a lone wise man. But it’s not hard to see why she would focus exclusively on this man, getting wrapped up in his history and the relationships he maintains today, which seemingly survive his long absences intact. Branneman’s combination of mastery and modesty is crowd-pleasing, and Buck benefits from a similar easygoing focus.