While it wasn't great literature, several years ago (late 80's or early 90's, although I don't know how old the book was then) I enjoyed a novel that combined a couple of my favorite things, science fiction and baseball. It is set in the not too distant future. In it, a baseball fan is somehow required to pitch for his favorite team - which I think was the Chicago Cubs. My recollection is that he wore a mask or helmet to hide who he was; while he didn't do particularly well on the field personally, the team was fairly successful overall (especially for the Cubs! ;-) Unfortunately, I don't remember a lot of other details.
Can anyone provide the title and author?