1909 Major League Baseball season

The 1909 major league baseball season began on April 12, 1909. The regular season ended on October 7, with the Pittsburgh Pirates and Detroit Tigers as regular season champions of the National League and American League, respectively. The postseason began with Game 1 of the sixth modern World Series on October 8 and ended with Game 7 on October 16. The Pirates defeated the Tigers, four games to three.

In the National League, the Chicago Cubs had a record of 104–49 but finished $6 1/2$ games behind the Pirates, setting a record for the most wins in an MLB regular season without reaching the postseason, which has only been equaled once, by the 1942 Brooklyn Dodgers, who had a record of 104–50.

Schedule
The 1909 schedule consisted of 154 games for all teams in the American League and National League, each of which had eight teams. Each team was scheduled to play 22 games against the other seven teams of their respective league. This continued the format put in place for the season. This format would last until.

Opening Day took place on April 14 with all but the Pittsburgh Pirates and St. Louis Cardinals playing. The American League would see its final day of the regular season on October 3, while the National League would see its final day of the regular season was on October 7. The World Series took place between October 8 and October 16.

Rule changes
The 1909 season saw the creation of a rule that a pitcher must face a minimum of one batter, due to a time-wasting trick to enable a team's intended pitcher to warmup for longer. This had previously occurred when one pitcher initially threw warmup pitches on the mound, before being taken out of the game (before facing a batter) to make way for a relief pitcher who now had extra warmup time.

Teams
An asterisk (*) denotes the departure from a ballpark mid-season.

Bracket
 

American League
1 American League Triple Crown batting winner

Events

 * August 28 – Dolly Gray of the Washington Senators walks eight batters in an inning.