Major League Baseball
Updated: Wikipedia source
Major League Baseball (MLB) is a professional baseball league in North America composed of 30 teams, divided equally between the National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. MLB is one of the major professional sports leagues in the United States and Canada and is considered the premier professional baseball league in the world. Each team plays 162 games per season, with Opening Day held during the last week of March or 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 headquartered in Midtown Manhattan.
Formed in 1876 and 1901, respectively, the NL and AL cemented their cooperation with the National Agreement in 1903, making MLB the oldest major professional sports league in the United States and Canada. They remained legally separate entities until 2000, when they merged into a single organization led by the commissioner of baseball. Baseball's first all-professional team, the Cincinnati Red Stockings, was founded in 1869. The first few decades of professional baseball saw rivalries between leagues, and players often jumped from one team or league to another. These practices were essentially ended by the National Agreement of 1903, in which AL and NL agreed to respect each other's player contracts, including the contentious reserve clause, which bound players to their teams. The period from about 1900 to 1920 was the dead-ball era, when home runs were rarely hit. Professional baseball was rocked by the Black Sox Scandal, a conspiracy to fix the 1919 World Series. Baseball survived the scandal, albeit with major changes in its governance as the relatively weak National Commission was replaced with a powerful commissioner of baseball with near-unlimited authority over the sport. MLB rose in popularity in the decade following the Black Sox Scandal, and unlike major leagues in other sports, it endured the Great Depression and World War II without any of its teams folding. Shortly after the war, Jackie Robinson broke baseball's color barrier. Some teams moved to different cities in the 1950s and 1960s. The AL and NL added eight clubs in the 1960s, which started the expansion era: two in 1961, two in 1962, and four in 1969. Player discontent with established labor practices, especially the reserve clause, led to the organization of the Major League Baseball Players Association to collectively bargain with the owners, which in turn led to the introduction of free agency in baseball. Modern stadiums with artificial turf surfaces began to change the game in the 1970s and 1980s. Home runs began to dominate the game during the 1990s. In the mid-2000s, media reports disclosed the use of anabolic steroids among MLB players; a 2006–07 investigation produced the Mitchell Report, which found that many players had used steroids and other performance-enhancing substances, including at least one player from each team. MLB is the third-wealthiest professional sports league in the world by revenue after the National Football League (NFL) and the National Basketball Association (NBA). Baseball games are broadcast on television, radio, and the internet throughout North America and in several other countries. MLB has the highest total season attendance of any sports league in the world; in 2024, it drew 71.4 million spectators. MLB also oversees Minor League Baseball, which comprises lower-tier teams affiliated with the major league clubs, the MLB Draft League, a hybrid amateur-professional showcase league, and the Arizona Fall League, an off-season showcase league for minor league players. MLB and the World Baseball Softball Confederation jointly manage the international World Baseball Classic tournament. The New York Yankees have the most championships with 27. The reigning champions are the Los Angeles Dodgers, who defeated the Toronto Blue Jays in the 2025 World Series.