Just look at that poster. Take it in. Could it be more cheesy? Well, I guess you could have some puppies running along with him, or some kids, maybe an angel lifting him up to catch that pop fly.
To accept a film like THE NATURAL you have to consciously let your intellectual guard down. The place of realism has no pace in the underdog story of Robert Redford as a baseball player that enters the majors late in his life and starts a winning streak. This film is a painterly portrait of a fictional Americana where the Good Guys (TM) are GOOD and the Bad Guys (TM) are BAD. The director has no qualms about the fact that he's painting a straight faced mythology for the audience. The picture doesn't cleverly states that Robert Redford is Christ like figure - it goes out of its way to show you in a number of different way: Redford affects weather, he hits impossible balls and he never quits. If you don't believe, you won't make it. If you're a cinema goer you're aware of the tropes that come with the Sports Story you're also aware that they can be done well and done badly. In THE NATURAL they're done wonderfully. Director Barry Levinson knows the film he's making and he sticks to those roots. No matter how syrupy the on screen action gets, the audience can go along without being torn out of it, and that's the most important part of all.