"sit in a room with three other knuckleballers and just talk knuckleballs"

Despite their lack of familiarity with the subject, the two women, best known for their Emmy-nominated documentary films "Joan Rivers: A Piece of Work" and "The Devil Came On Horseback" (about the genocide in Darfur) jumped at the chance to bring the story of the controversial, oft-misunderstood pitch that has baffled batters and catchers for decades to the big screen.

"We're really attracted to the characters -- the individuals and people who have obstacles and something to overcome in pursuit of their dreams," Stern said. "For us, that just makes strong storytelling. The essence of what the symbolic meaning of the knuckleball embodies. These guys are outliers in baseball who struggle against all odds to stay in the game to pursue their dreams. They kind of clawed their way, as they say, with their fingertips -- just like one holds the ball with one's fingertips -- back into the major leagues."

"These guys" refers primarily to Tim Wakefield and R.A. Dickey, the two knuckleball pitchers in the majors during the 2011 season. It also includes retired knuckleballers, Charlie Hough, Jim Bouton, Tom Candiotti, Wilbur Wood and Hall of Famer Phil Niekro, who are a handful of the approximately 80 men who have been members of the knuckleball fraternity.

Read More | "'Knuckleball!' film about life more than sport" | Amanda Rykoff | ?ESPN