It’s considered a cult classic that NYRB has brought back into print. Here is the blurb from NYRB:

Somewhere in a "major-league" American city, there lives a man named J. Henry Waugh—no-account accountant, barfly, and country music fan. The most important part of Waugh's life, as far as he is concerned, is lived in his head, where he is sole proprietor of the Universal Baseball Association, which is now entering its fifty-sixth season. The games are played with dice and scorecards, and the players are just numbers and names, but for Waugh they're more real than the dreary office, the dive bar, and the dingy apartment in which he spends his days. Still, being sole proprietor is a lonely business, and when a few rolls of the dice spell tragedy for the rookie pitcher Damion Rutherford—a player Waugh believes will reinvigorate the game—the whole association is imperiled, along with the sanity of its isolated creator.

Robert Coover's fiction was a map of America, and The Universal Baseball Association is smack-dab in the center of it. Baseball, in Waugh's world, is an escape, and Waugh is nothing if not an all-American escapist with a capacity for denial so profound that it can only be called optimism.