American League (Major League Baseball)

Structure and members

Today the American League includes 15 clubs organized into three divisions: AL East, AL Central and AL West. Teams play the majority of their schedule against league opponents, with a smaller number of interleague games against National League clubs. The league's clubs compete during the regular season for divisional titles and playoff berths; historically five teams reached the postseason from the AL under an earlier format, though playoff formats have been expanded in recent years.

Notable rules and distinctions

A long-standing difference between the AL and NL was the designated hitter (DH) rule: the American League adopted the DH before the National League, allowing a hitter to bat in place of the pitcher. That rule shaped lineup construction and strategy in the AL for decades. Interleague play and other rule changes have narrowed some distinctions between the leagues, but the AL pennant remains a major seasonal objective.

History and development

The American League began as a separate circuit at the start of the 20th century and quickly established itself as a major-league partner to the National League. Early competition and occasional contract disputes between the leagues gave way to cooperation, including an annual championship series between league winners. Over time the governance of the game centralized: league offices were restructured and many administrative duties shifted to MLB's central office, while the AL identity endures through its teams, trophies and traditions.

Postseason and the World Series

The winner of the American League's postseason is crowned the AL champion (often called the AL pennant winner) and advances to play the National League champion in the World Series, the championship series that determines the overall MLB champion. The AL postseason has included division series and championship rounds; formats have been modified at different times to expand participation and create staged series between wild-card and division winners. The AL champion is sometimes described simply as "the team that wins the American League" or the American League championship.

Examples, importance and culture

Some of the most storied franchises in North American sports compete in the AL, contributing to regional rivalries, historic ballparks and strong fan traditions. The league plays an important role in player development, rule experimentation and the sport's commercial life. With 15 teams listed in league rosters, the AL's clubs are the subject of regular coverage and fandom across many cities and national markets (15 teams in total).

Further reading

• Overview of the two-league structure: comparison of the two major leagues
• Official Major League Baseball information: MLB
• Relations with the National League: National League
• League membership and teams: current teams
• AL championship and pennant history: American League championship
• The World Series matchup: World Series