Continuity mistake: When 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.
Suggested correction: They were playing at Knight's Field in New York. Plus the scoreboard has them batting last.
He's talking about the first game in Chicago when Iris stood up.
Suggested correction: Not everyone starts to leave, it's just a few guys sitting next to Iris that start to leave their seats. And all the photographers and reporters are crowding around Hobbs not because New York won, but because he hit such a big home run. Then the scene ends and cuts to the locker room to save time since we don't need to see the Cubs last at bat.
Continuity mistake: We first see from the inside of the door (and therefore backwards) the instructions that Mr. Miyagi leaves for Daniel to paint the house. In the next shot we see the same note from the outside - from Daniel's viewpoint. Clearly they are two different notes. The left & right arrows switch directions, the drawings of the hands change, the position of Miyagi's signature changes, and the placement of some of the exclamation points changes.
Continuity mistake: In the first skiing sequence with the rad pack, Michelle "Banana Pants" jacket changes from red to blue between shots. (00:32:10)
Continuity mistake: During the Grand National, the leading horse unseats its rider at the third fence (jockey with pink and black spots), but just a few minutes later the same horse and jockey combination are back up with the pace.