Canadian Football League
The regular season is 21 weeks long, with games beginning in mid-June and finishing by early November. The CFL's nine current teams are divided into two divisions: the East Division with four teams and the West Division, with five teams. Each team plays two games against each of the other eight teams, plus two divisional games with opponents rotating each season. With 18 regular season games being played, each team gets three bye weeks.
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.