Jason Ross is an 11-year-old boy whose love for baseball exceeds his talent for the game. When cut from his little league team, Jason's undefeatable spirit leads him to try and create an expansion team. In searching for a new coach, Jason comes to believe that Mack Henry, the custodian at his school, is really Buck McHenry, the legendary pitcher from the old Negro Baseball Leagues. While Mack begins to coach this small rag-tag team, Jason and his friends set out to prove his true identity.