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.
Major professional sports leagues in the United States and Canada
MLB, NBA, NFL, and NHL are commonly referred to as the "Big Four." Each of these is the wealthiest professional club competition in its sport worldwide, and along with the English Premier League they make up the top five sports leagues by revenue in the world. In addition, the sports of these four leagues were all developed in their modern forms in North America, and all except American football have become popular internationally. Because the leagues enjoy a significant place in popular culture in the U.S. and Canada, the best players from these leagues often become cultural icons in both countries. Each Big Four league, as well as Major League Soccer and Canadian Football League, averages at least 15,000 fans in attendance per game as of 2018.