Divisional Era (since 1969)

Definition

With the expansion of 1969, which brought the total number of teams in each league to 12, both leagues were split into two divisions of six clubs each -- a Western Division and an Eastern Division.

The American League East consisted of Cleveland, the Baltimore Orioles, Boston Red Sox, Washington Senators, Detroit Tigers and New York Yankees. The AL West consisted of the California Angels, Oakland Athletics, Seattle Pilots, Kansas City Royals, Minnesota Twins and Chicago White Sox.

The National League East consisted of the St. Louis Cardinals, Chicago Cubs, Montreal Expos, New York Mets, Philadelphia Phillies and Pittsburgh Pirates. The NL West consisted of the Houston Astros, Atlanta Braves, Los Angeles Dodgers, San Francisco Giants, San Diego Padres and Cincinnati Reds.

The creation of divisions in each league also necessitated a new round of the postseason that would precede the World Series, bringing the playoff format closer to the one MLB utilizes today. The winner of each division would face off in the League Championship Series, with the winner of each LCS advancing to the World Series.

Initially, the LCS was a best-of-five series, but it was expanded to a best-of-seven series beginning in 1985.