Hadley's Rebellion (1983)

After he transfers to a new school, Hadley is victimized and ostracized by his too-cool classmates. To prove his worth, our hero takes up wrestling, and before long he’s the school champ, thanks to the input of coach Ball, a washed-up alcoholic who finds redemption through Hadley’s example.

Unfortunately the movie Hadley's Rebellion is not yet available on HBO Max.