ESPN has a nice piece up about this great piece of cinema here. From the link, a little nostalgia:
Bull Durham was the creation of a man who'd been cast aside by the game he loved. Ok, he walked away, but in the early '70's, Ron Shelton was a 26-year-old minor leaguer whose chances at the show were dwindling. So he quit. Fifteen years after his love affair with baseball ended, he made Bull Durham in 1988 for a paltry $9 million, going to great lengths to cast actors who could actually play. The movie was a hit, and baseball player-turned-filmmaker was in Hollywood's door. Twenty years later, Bull Durham is still widely considered among the top sports movies ever made, and is BRAVO's choice for best comedy ever.
A-friggin-men..I love this damn movie. It was all downhill after this for Costner btw.