"Coyote Moon" is a 2003 novel by John A Miller. It falls roughly in the category of literary fiction, with some possible science-fiction elements. It is unclear in this book whether these elements are "real", or whether the book is engaging in some "magical realism". I found this book in a Little Free Library, and I could find little information about the author online.
The book has two parallel plots: in one, Benny Rhodes, a physics professor from MIT, depressed over the loss of his friend, has moved to a trailer park outside Needles, California, where he befriends a group of German immigrants, as well as some long-time residents of the park. In the other, a young baseball player named Henry Spencer, with no prior record shows up at spring training and soon shows himself to be an incredibly skilled player, who is soon shifted to major league play. Along with setting records for hitting and catching, young Spencer also is a moral paragon and starts spouting off about quantum physics. The book is set up in such a way that its suggested that Spencer is the reincarnation of Rhodes' deceased friend, Art Hodges. In fact, the inside book jacket says as much. Clues are laid out, as finally Rhodes and Hodges are reunited. The book is ambiguous about whether there really was anything supernatural, although it seems to suggest there was not.
This book left me disappointed. It promised a touch of the surreal, but it turned out to be a pretty basic story about boomer angst with some quantum physics thrown in. As I mentioned previously, adding quantum physics to a book doesn't necessarily make it smarter. In fact, I can say it very rarely does. The book also has some flat characterization, including Henry Spencer, who is described as the best baseball player in the history of the game, a genius, a paragon, and also, repeatedly, as having a penis so large that random women notice it and can't keep their eyes off of it, including, when he goes to the hospital, the nurses rearranging their shifts because they want to stare at his huge penis, because that is totally a thing that nurses do.
The book comes to some sort of denouement, and while it isn't terrible, it throws away much of what it has established. My summary of this book is: don't try to add quantum physics just because.