“The Battered Bastards of Baseball” chronicles the unlikely success of the Portland Mavericks, a 1970s independent baseball team founded by actor Bing Russell. After Portland lost its minor-league affiliate, Russell created a single-A team filled with players rejected by the major leagues.

Defying conventional norms with open tryouts and an anti-establishment ethos, the Mavericks took on established teams and won, drawing record crowds in the process. The documentary is a compelling look at sports outliers who became symbols of the independent spirit in America’s favorite pastime.