1918 Major League Baseball season

The 1918 major league baseball season began on April 15, 1918. The regular season ended earlier than originally scheduled, September 2, because of a reduced schedule due to American participation in World War I. The National League and American League champions were the Chicago Cubs and Boston Red Sox, respectively. The postseason began with Game 1 of the 15th World Series on September 5 and ended with Game 6 on September 11. The Red Sox defeated the Cubs, four games to two.

Scheduled start
Opening Day took place on April 15 with four American League teams playing, the Philadelphia Athletics at Boston Red Sox, and the New York Yankees at Washington Senators.

Shortened season
With World War I ongoing, a "work or fight" mandate was issued by the government, requiring men with non-essential jobs to enlist or take war-related jobs by July 1, or else risk being drafted. Secretary of War Newton D. Baker granted an extension to MLB players through Labor Day, September 2. In early August, MLB clubs decided that the regular season would end at that time. As a result, the number of regular-season games that each team played varied—123 to 130 for AL teams and 124 to 131 for NL teams, including ties —reduced from their original 154-game schedules. Later in August, Baker granted a further extension to allow for the World Series to be contested; it began on September 5 and ended on September 11. World War I would end two months later, with the Armistice of 11 November 1918.

Bracket
 

American League
1 American League Triple Crown pitching winner

National League
1 National League Triple Crown pitching winner

Notable events

 * September 2 – In the last game of the season, against the Chicago White Sox, Detroit Tigers centerfielder Ty Cobb fields at third base and also pitches, yielding three hits and one run in two innings.