Rise and fall of colorful boxer

One doesn’t need to be into pugilism or well-versed in Gaelic to appreciate “Rocky Ros Muc,” a documentary that is as much about roots and identity as it is a portrait of Irish American boxer Sean Mannion.

Hailing from the village of Ros Muc, some 37 miles west of Galway, Mannion, like many of his fellow emigrés, formed a tight-knit community on South Boston’s Dorchester Street, where the light middleweight would find eager sparring partners in members of Irish crime boss James “Whitey” Bulger’s Winter Hill Gang.

With quality pub time contributing to his weight gain issues, Mannion may not have been the most disciplined of fighters, but his determination took him farther than most, leading to a 1984 Madison Square Garden bout against Jamaican Mike McCallum for the World Boxing Assn. world title.

While director Michael Fanning adheres to a familiar schematic, with mates, family members and biographer Rónán Mac Con Iomaire weighing in on Mannion’s rise-and-fall trajectory, it’s the man himself, now 61, who tells a more compelling story.

Despite his successes, there’s a telltale couldabeen-a-contender look of regret in Mannion’s eyes that speak of hard knocks and an alcohol-fueled downward spiral.

The one constant has been Ros Muc, the name emblazoned on the waistband of his boxing shorts that served as a lifelong reminder of the place that would always have his back.

“Rocky Ros Muc.” In English and Gaelic with English subtitles. Not rated. Running time: 1 hour, 32 minutes. Playing: Laemmle Music Hall, Beverly Hills.