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.
Professional football (gridiron)
Indoor football has also developed in the United States, beginning with the Arena Football League, which formed in 1987. The AFL is the second longest running professional football league in the United States after the NFL, although its current incarnation is a separate entity from the original, which folded due to bankruptcy in 2008. From its debut until 1997, the Arena Football League operated with a monopoly on the indoor game, due to a broad interpretation that virtually all of the league's rules, collectively known as arena football, were covered under its patent; the Professional Indoor Football League successfully defeated the AFL's legal action against it in 1997, opening the possibility for other indoor football leagues to form. Only one significant aspect of the patent, the large rebound nets the AFL has used since its debut to keep balls in play, was fully protected; the patent expired in 2007, although no other professional indoor league has adopted rebound nets since. As of 2011, two national leagues (the AFL and the Indoor Football League), along with several regional professional and semi-pro leagues, are in operation. As of 2011, no professional indoor football league has had any significant presence in Canada (despite an abundance of hockey arenas that are ideal for the game); only one indoor team, the AFL's short-lived Toronto Phantoms (2000 to 2002), has ever played its games in Canada. The all-female Lingerie Football League had operations in Canada from 2011 to 2014, but that league dropped to amateur level by the time the LFL entered the country.