‘Knuckleball!’ the film opens in Boston Sept. 18

By Doug Most, Globe Staff

Sox fans need something to smile about in September since a playoff run seems all but dead. Here it is.

We’ve told you about “Knuckleball!,” the baseball documentary that follows now-retired Sox favorite Tim Wakefield and present-day Mets pitching star R.A. Dickey. You’ve even had chances to see it at several local area film festivals. But now it’s really coming, opening Tuesday, Sept. 18 at the Regal Fenway Stadium 13 in Boston and Sept. 19 at Coolidge Corner Theater (and it will also be available on on-demand TV). And if the trailers are any indication, it looks like a must-see for Sox fans, no matter what color their hats.

In the film, by a pair of Dartmouth graduates, Ricki Stern and Annie Sundberg, Wakefield and catcher Jason Varitek are prominent, along with Boston.com sportswriter and 98.5 FM sports talker Tony Massarotti , and the Yankee who has beaten us so many times, Derek Jeter. There are also lots of crowd shots at Fenway and poignant images of Wakefield, always one of the team’s most charitable guys, blowing out birthday candles with kids. “Knuckleball!” was voted one of the top films at the 2012 Tribeca Film Festival.

“Everything you are taught as a catcher goes out the window,” Varitek says of the experience of trying to catch a knuckleball, while standing on the field at Fenway. “At the last second the ball can change direction.”

Says Jeter, while shaking his head in a locker room after facing Wakefield, “I don’t even think he knows where it’s going.”

Sadly, that’s followed by the clip of Wakefield’s pitch that Aaron Boone deposited in the left-field seats at Yankee Stadium to end the Sox 2003 season, and a shot of a dejected, slumped over Wakefield in the clubhouse.

“Nobody trusts the knuckleball,” Massarotti then says. “Nobody.”