The Ontario Hockey League (OHL; French: Ligue de hockey de l'Ontario (LHO)) is one of the three major junior ice hockey leagues which constitute the Canadian Hockey League. The league is for players aged 16–21. There are currently 20 teams in the OHL; seventeen in Ontario, two in Michigan, and one in Pennsylvania. The league was founded in 1980 when its predecessor, the Ontario Major Junior Hockey League, formally split away from the Ontario Hockey Association, joining the Canadian Major Junior Hockey League and its direct affiliation with Hockey Canada. The OHL traces its history of Junior A hockey back to 1933 with the partition of Junior A and B. In 1970, the OHA Junior A League was one of five Junior A leagues operating in Ontario. The OHA was promoted to Tier I Junior A for the 1970–71 season and took up the name Ontario Major Junior Hockey League. Since 1980 the league has grown rapidly into a high-profile marketable product, with many games broadcast on television and radio.