One thing this past year confirmed was that these handsome, movie-idol personalities can really act. Too often Pitt and Clooney have been constrained by their leading man status to playing cool protagonists who save the day and get the girl. And they appear to be playing themselves.
Our enjoyment of a film depends on our ability to suspend disbelief. Sports movies based on true stories are at a severe disadvantage in this regard. Many of us are acutely aware of every last detail of a sports film. Sports fans are conditioned that way. It's in our DNA.