DURHAM, N.C. – Ron Shelton says he’s just now realizing what a home run he hit with “Bull Durham.”

Two decades have passed since the release of the movie Shelton wrote and directed about an aging minor league catcher, a hotshot pitching prospect and the groupie wooed by both that has been praised as one of the top sports movies of all time.

“It’s just dawning on me now, really,” Shelton said Wednesday. “We realized when we started testing that the audiences responded to it. It never scored through the roof when it scored; it sort of got these OK numbers.

“But when it opened and these reviews came in that my mother couldn’t have written. … In the second week, it stayed and it stayed and it just ran all summer. It was a gradual recognition that maybe we captured lightning in a bottle here, (but) there was no moment of epiphany.”

Shelton joined producer and Durham native Thom Mount at a luncheon marking the 20th anniversary of the film that captures a season with a fictitious version of the Durham Bulls, then of the Class A Carolina League.

They’ve discussed the possibility of a sequel to the 1988 film, in which journeyman catcher Crash Davis (Kevin Costner) and superfan Annie Savoy (Susan Sarandon) counsel fireballer Nuke LaLoosh (Tim Robbins) on his way to the major leagues.

“It was such a completed fable that it was hard to go back,” Shelton said. “I couldn’t figure out in the few years right after it came out, what do you do? Nuke’s in the big leagues, Crash is managing in Visalia. Is Annie going to go to Visalia? I’ve been to Visalia. That will test a relationship. … It was not a simple fable to continue with – not that we don’t talk about continuing it, now that everyone’s in their 60s.”

The film has held up remarkably well since hitting theaters in June 1988, and so have the Bulls.

Now Tampa Bay’s Triple-A affiliate, the Bulls have been one of the most popular teams in the minors, attracting a club-record 520,952 fans last season and annually ranking near the top of minor league baseball in merchandise sales. Mementos from the film are sprinkled throughout the new stadium, with a movie poster greeting visitors entering club offices and an enlarged replica of the “Hit bull, win steak” sign enticing hitters from atop the left-field wall.

Not to be outdone, the Bulls’ old ballpark – where much of the movie was filmed in the fall of 1987 – is receiving a facelift.

Shelton’s appearance coincided with the groundbreaking of a $5 million renovation of Durham Athletic Park, the cozy, 70-year-old field called home by the real-life Bulls until 1994. The park helped convince Shelton, a former minor league second baseman, to set the film here.

“I drove all over minor leagues in the South and kept coming back to Durham,” Shelton said. “I loved the old ballpark. I loved that it was located among abandoned tobacco warehouses and on the edge of an abandoned downtown and in the middle of a residential neighborhood where people could walk.

“In the 80s, minor league baseball wasn’t happening. Now, of course, it’s huge business. I thought that it had a feel of the kind of baseball I loved – small-town, intimate, the players could talk to fans and back and forth. It kind of visually and aesthetically stood for everything that Major League Baseball was not.”