Ricki Stern and Anne Sundberg — the directors of baseball doc “Knuckleball!” starring R.A. Dickey — will helm one of nine documentaries commissioned for ESPN’s upcoming “Nine for IX” film series. (The series’ name is inspired by the 40th anniversary of Title IX, the 1972 legislation that gave female athletes equal opportunities in college sports.) Stern and Sundberg’s movie will focus on the controversial history of women journalists being admitted to men’s locker rooms. ESPN has yet to officially announce its lineup of filmmakers. The directors’ take on baseball’s quirky knuckleball pitchers, also featuring Tim Wakefield, premiered at the Tribeca Film Festival and was prescient since Mets star Dickey went on to win 20 games and become the first-ever knuckleballer to get the Cy Young Award. Stern and Sundberg told us they’d met with ESPN about their upcoming doc while shooting “Knuckleball!” and that spending time in MLB locker rooms as women informed their material for their next project. As for backing the right horse to profile in Dickey, the pair told us, “We were happy for R.A. as a friend. It was exciting to get to know him and his family.”