M5V 1J1, 1 Blue Jays Way Major League Baseball (MLB) is a professional baseball league with the highest level of organized baseball in the United States and Canada. One of the four major leagues, MLB, comprises 30 teams, divided equally between the National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada.
Each team plays 162 games per season, with Opening Day traditionally held during the first week of April. Six teams in each league then advance to a four-round postseason tournament in October, culminating in the World Series, a best-of-seven championship series between the two league champions first played in 1903.
MLB is the second-wealthiest professional sports league by revenue after the National Football League (NFL).
MLB also oversees Minor League Baseball, which comprises lower-tier teams affiliated with the major league clubs. MLB and the World Baseball Softball Confederation jointly manage the international World Baseball Classic tournament. Wikipedia