October belongs to Major League Baseball. Why? Because that is when the postseason begins for the top teams that make the playoffs. Until 1969, when there were no divisions, the team finishing with the best record in each league won that league's pennant and faced the other league's pennant winner in the Fall Classic.
In 1969, however, the sport experienced a major shift in its post-season process after both the American and National Leagues added two more teams each and reorganized into two divisions, the East and West. As a result, the winners in each division were now required to play each other in a best-of-five League Championship Series to determine who would advance to the World Series. In 1985, the format was changed to a best-of-seven contest, where it has remained to this day.
Technically, the first division series were in the strike-interrupted year of 1981. Due to the two-month strike, Major League owners elected to split the 1981 season into two halves, with the first-place teams from each half in each division meeting in a best-of-five divisional playoff series. The winner of each of these series was then the division winner facing the other division winner in the League Championship Series. However, there would be no more division series until 1995.
Beginning with the 1994 season, baseball added a third division, the Central, to accommodate the introduction of expansion teams and realignment. Because of the strike that season, there were no postseason games. Thus the Divisional Series premiered in 1995, adding another elimination round to the playoffs. The American League Division Series and National League Division Series have given birth to many memorable moments.
How does it currently work? The Divisional Series is a best-of-five series, featuring the three division winners and a wild-card team. Typically, the wild-card team plays the division leader with the best winning percentage in one series, and the other two division leaders play the other series. However, if the wild-card team and the division leader with the best record are from the same division, the wild-card team plays the next winningest division leader, and the remaining two division leaders play. The teams with the better winning percentage get homefield advantage (home team for games 1, 2 and 5). The two Division Series winners move on to the best-of-seven League Championship Series to determine the pennant winner and league representative for the World Series. Research by Baseball Almanac.
"Perhaps this latest wild-card wackiness will prove to be little more than an unfortunate rain delay, but don't wait till next year; this may be our last and best September." - Shapiro, Walter. Columnist. Time Magazine. October 1993.
The Division Series is the quarterfinal round of the Major League Baseball postseason. Four series are played in this round, two each for both the American League and the National League. Since the Division Series started in 1981, the New York Yankees (American League) have made the most appearances (24), and won the most (15). In the National League, the Atlanta Braves had made the most appearances (19), but they were tied by Los Angeles Dodgers in 2024 (19). The winningest senior circuit team is the St. Louis Cardinals (11).
Divisions / alignments have changed many times since 1969 and writer Tom Verducci of Sports Illustrated once said in 1995, "The format is harder to understand than the essay question on a Russian literature exam. The American League's official media guide, the Red Book, even had it wrong! When an Indian official telephoned both the American and National league offices to find out which league champion has the home field advantage in the World Series, he received two different answers."
What was the best Division Series ever played in baseball history? Should Major League Baseball give out a Division Series MVP? Which two division series teams should have never even made the playoffs? Please, tell us your opinions in our Baseball Almanac Facebook Group, on Baseball Almanac Twitter, via Baseball Almanac Messenger, or our baseball forum — Baseball Fever.