Professional football in Canada
Only one professional football league has a permanent presence in Canada: the Canadian Football League (CFL), an organization founded in 1958 to accommodate the ongoing trend of professionalism in the Canadian football ranks since the 1940s. The CFL, like most amateur Canadian football leagues, plays on a larger field using a rulebook with several significant rule differences compared to the game as it is played in the United States. The league is composed of two divisions and nine teams in most of the largest Canadian markets, with at least one team in each province between British Columbia (BC Lions) and Quebec (Montreal Alouettes) inclusive. The only presence in Atlantic Canada is a semi-regular series of games in Moncton (Touchdown Atlantic) and a smattering of earlier preseason contests. The CFL operates a two-week preseason beginning in June, an 18-game season from July to October, and a six-team playoff tournament, culminating in the Grey Cup on the fourth weekend of November.
Canadian Football League
From the 1930s to the 1950s, the two senior leagues of the CRU, the eastern Interprovincial Rugby Football Union (IRFU or Big Four) and Western Interprovincial Football Union (WIFU) gradually evolved from amateur to professional leagues, and amateur teams such as those in the Ontario Rugby Football Union (ORFU) were no longer competitive for the Grey Cup. From 1945 onward, the WIFU's champion faced the Big Four's champion for the Grey Cup, though until 1954 it had to play in a semi-final against the champion of the ORFU–by then, the only amateur union still competing for the Grey Cup. The ORFU withdrew from Grey Cup competition after the 1954 season, and the WIFU champion was automatically awarded a berth in the Grey Cup final. For this reason, 1954 is reckoned as the start of the modern era of Canadian football, in which the Grey Cup has been exclusively contested by professional teams. Since 1965, Canada's top amateur teams, competing in what is now U Sports, have competed for the Vanier Cup.