Continuity: In the scene where he hits the ball off the clock, everyone leaves the park after his home run. Why should they? Roy Hobbs' team is the visiting team, so the Chicago Cubs still have their turn at bat in the bottom of the ninth.
Continuity: During the scene in a coffee shop or diner after Glen Close has come to see Robert Redford play baseball, her coffee cup and saucer disappear and reappear throughout the entire scene.