Redemption and family are two themes in John Grisham's novels, and we certainly have both here. One story in Calico Joe involves a bitter, aging pitcher and the rising star whose career is ruined with one beanball. The other involves the same bitter man and his failure as a father. The story moves between first person and third and back in forth in time, between the son and his trip to see his dying father and the events leading up to the awful game. This can be a little confusing, but I got used to it pretty quickly. (I never did get quite used to the verb tense shifts though.)
On certainly does not have to be a baseball fan to appreciate the history of the game, which Grisham clearly knows and loves, or to enjoy reading about these people. The narrator is as interesting a character as the title character, Warren Tracy, and Clarence Rook, though not as dynamic as one might expect. But that is not necessarily a flaw. Sometimes a novel's best message is in what it doesn't say, not it what is beat over our heads.
I fully expect this book to be made into a movie, and when it is, I hope it is handled by a bright and creative director instead of getting turned into a Hallmark presentation. Otherwise much of the real grit of the issues addressed in Calico Joe are likely to be lost, and that would be a shame.