Paul Newman had stated on many occasions that he had more fun making this film than on any other film he has starred in, and that it remained his favorite of his own films until his death.
Bruce Boudreau, head coach of the NHL's Vancouver Canucks (2021-2023), appears in the film wearing #7 for the Hyannisport Presidents. Boudreau was one of several players for the Johnstown Jets minor league hockey team that were used as extras.
Many of the players in the game scenes (as well as the Hanson brothers) played for the Johnstown Jets, a team in the now-defunct minor-pro North American Hockey League. The Charlestown Chiefs were based on the Jets.
Reggie's apartment in this movie is the actual apartment of Bruce Boudreau, who, at the time, played for the Johnstown Jets, the team the Chiefs were modeled on.
During rehearsals, Yvon Barrette was seriously injured when a puck hit him in the knee. Barrette was worried that he would be replaced with another actor. But George Roy Hill postponed shooting scenes featuring Barrette so that he could return to the film when he recovered. Barrette returned to filming 10 days later. But to prevent any further injury, Barrette was doubled by Ronald L. Docken during the hockey playing scenes.