Major League Baseball (MLB) is the highest level of professional baseball in the world, consisting of teams that play in the American League and the National League. The two leagues merged in 2000 into a single organization led by the Commissioner of Baseball, after 100 years as separate legal entities MLB constitutes one of the major professional sports leagues of the United States and Canada. It is composed of 30 teams — 29 in the United States and 1 in Canada. With the International Baseball Federation, MLB also manages the World Baseball Classic. With an average attendance of 30,352 people per game, Major League Baseball has the fifth highest average attendance of any sports league behind the NFL, Bundesliga, AFL, and Premier League.