When Rain Man was released in 1988, the film immediately received praise from the public and from critics, going on to gross more than any other film that year. Even those who never watched the movie inevitably learned something new. Some were intrigued by Dustin Hoffman’s character’s ability to count cards in blackjack. Others wanted to learn more about the life of savants.

Thirty years after the film’s release, some critics have looked back at Rain Man, written by Barry Morrow, and wondered if the film’s initial praise was too kind. Once again, some focused on the film’s treatment of Hoffman’s character, named Raymond, who is an autistic savant. They wondered if the character helped shed light on the condition or misrepresented autism.

However, most of Rain Man’s misgivings relate to the world of card counting. In the film, Raymond can count cards on...