Richard Linklater did in fact play baseball in his school years. He always remembered how everyone in his team were competitors and would compete at just about anything to prove who was better. A lot of this film is autobiographical like many of his films and just like in this film, he remembered what was great about those days wasn't just about the baseball games but mainly the things he and his team mates got up to.
The film takes place from August 28 to September 1, 1980.
The bar The Fox is an actual bar called the Jolly Fox in Huntsville TX, where Linklater went to college and played baseball. The sign on the wall in the movie actually says Jolly Fox.