Major professional sports leagues in the United States and Canada
traditionally include four leagues: Major League Baseball (MLB), the National
Basketball Association (NBA), the National Football League (NFL), and the
National Hockey League (NHL). Other prominent leagues include Major League
Soccer (MLS) and the Canadian Football League (CFL).
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.
Each of the Big Four leagues, as well as MLS and the CFL, averages at least
15,000 fans in attendance per game as of 2023.