Before the colorful "idiots" who brought the World Series trophy to Boston a decade ago or the bearded bruisers who won another championship for the Red Sox last fall, there were the Portland Mavericks, an independent in every sense of the word professional baseball team. An hirsute collection of rejects from organized baseball with scores to settle, the Mavericks roared across the baseball firmament in the mid-1970s, and when they flamed out, they were the last minor league baseball team not affiliated with a major league team.

Close to 40 years later, the Mavericks have been reclaimed from the dustbin of baseball history in the documentary "Battered Bastards of Baseball." The Berkshire International Film Festival will screen the documentary at the Mahaiwe Performing Ars Center in Great Barrington in the high-profile 7 p.m., Saturday spot.

The "Battered Bastards of Baseball" is to a large extent the story of Bing Russell, the man who brought the team to Portland, Ore., after organized baseball abandoned the city. Bing was a veteran character actor, Westerns a specialty, who claimed to have been shot 127 times on screen in a career highlighted by 13 years as Deputy Clem on "Bonanza."

When "Bonanza" ended its run, Bing's actor son, Kurt, urged his dad to pursue his other passion -- baseball. Bing bought a franchise in the Northwest League and went on to fill its roster with players, many of them eccentric characters, cut by major league franchises. A fiery and fun-loving showman, Bing promoted his team aggressively and imaginatively, packed a ballpark that had previously drawn handfuls of fans, and shook up the staid world of baseball.

Bringing Bing and his creation back to life began as an exploration of family history conducted by brothers Chapman and Maclain Way, the grandsons of Bing. They were born long after the Mavericks' era, but they grew up a few houses down the street from their grandparents in Thousand Oaks, Calif., and were close to their grandfather, who was, in Chapman's words, "a colorful, larger-than-life character."

Four years ago, while visiting his grandmother (Bing died in 2003), Chapman saw an old photo of the Mavericks.

"This wasn't your usual baseball photo," says Chapman in a joint phone interview with his brother Maclain. "The guys were drinking beer, some had their uniforms on backwards, and there was a dog that appeared to be running through the shot."

The photo inspired Chapman to do more research into the photos and memorabilia that were still in the house. Experienced in cinematography and editing and a director of videos, he began to think that the Mavericks' story "would be a fascinating movie." Maclain, a history major who had done some documentary research, was recruited for what Chapman thought would make "an ideal team."

The brothers went up to Portland where Maclain the historian "just began cold-calling TV stations and inviting myself into their basements. I was amazed at the amount of footage that had survived nearly 40 years later."

The film that emerged contains choice excerpts of the nearly eight hours of film footage found in Portland, film and photos from the family's collection, including Super-8 footage of an entire championship game found in a mold-covered canister in Bing's attic, and contemporary interviews. It is a story of underdogs who refused to accept their station in life. They had a female general manager, which was unprecedented, and a left-handed catcher, which was at the least unusual.

The Mavericks played to win, not develop major leaguers, as did their Northwest League rivals, and they won with players who had been found lacking by major league executives. The independent teams that have sprouted all over America, including a couple that played not long ago in Pittsfield, are their legacy.

Because the Mavericks weren't popular with the baseball hierarchy, it was logical for them to sign Jim Bouton, a former New York Yankees' pitcher (and current South Berkshire resident) who had become a pariah by exposing what went on in dugouts, clubhouses and hotel rooms in his book "Ball Four." Bouton not only helped on the mound, he attracted national publicity for the Mavericks.

"Battered Bastards of Baseball" climaxes with the attempt of the Pacific Coast League to use its higher standing on the baseball ladder (the PCL is at the top or AAA minor league level, the Northwest League is at the A level) to push the Mavericks out of Portland and reclaim a city that major league affiliated baseball had abandoned as hopeless.

"That was a great issue for filmmakers to explore," says Chapman. "The bully came in to steamroll over the little guy, which is something that certainly resonates across America today."

In looking back to tell the story, the brothers relied heavily on interviews with the batboy and a young Mavericks player who, like the batboy, became well-known in Hollywood. The batboy, whose passion for baseball persuaded Bing to hire him, is Todd Field, who grew up to be an Oscar-nominated director and producer ("In the Bedroom," "Little Children") as well as an actor and writer. The player was Bing's son and the brothers' Uncle Kurt, star of "Escape From New York," "Tombstone" and many other films.

"He trusted us to tell the story," says Chapman of Kurt Russell. "He didn't see it until Sundance [the film festival where the documentary debuted] and I think it was a wonderful experience for him to see his dad brought back to life."

To see the documentary is to see its potential as a feature film, and with Field attached to the project, the brothers believe it will become a feature within two or three years. It may require the talents of the hair and costume specialists from last year's Oscar-nominated and 1970s-set "American Hustle," as the movie is riot of bad haircuts, "porn star" mustaches, bushy beards, unruly sideburns and garishly colored and far too snug clothes.

The Way brothers, producer Juliana Lembi and Bouton will be on hand to discuss "Battered Bastards of Baseball" after Saturday's screening.

It is against Mahaiwe rules, but it would be appropriate if hot dogs, popcorn, crackerjacks and plenty of beer were provided in honor of the Mavericks.