The Premier League is the top professional football league in England. It was formed in 1992 when clubs renounced the Football League to form their own competition. In its early decades, the "Big Four" clubs of Arsenal, Chelsea, Liverpool, and Manchester United dominated the top positions. The league has since expanded to 20 clubs and includes Welsh team Swansea City. Each team plays 38 games over the course of a season in a double round-robin format.