When interviewed during production of the film, John Goodman noted the irony of having to lose weight to play the part of Ruth.
In the film, "Jumping" Joe Dugan is portrayed as Ruth's teammate and mentor since Ruth's rookie year in Boston in 1914. In real life, Babe Ruth was sold to the Yankees in 1920. Joe Dugan didn't join the Red Sox until 1922 and the two weren't teammates until Dugan was traded to the Yankees midway through the 1922 season.
In the film, Babe Ruth is depicted as being overweight since his youth. In reality Babe never put on the weight until his adult life when he started making money playing ball enjoying the labors of his fortunes. He lost a lot of weight when he was first diagnosed with cancer.
When Babe Ruth gives a suit to Jumping Joe, he opens the hotel room door. The room number visible across the hall is 714, which is the number of home runs in Babe Ruth's career.
The minor league Danville Dans stadium in Danville, Illinois, was the one used for Fenway Park and Forbes Field, as well as being seen in black/white news footage.