Doubleheader (baseball)

Two baseball games between the same two teams on the same day

In the sport of baseball, a doubleheader is a set of two games played between the same two teams on the same day. Historically, doubleheaders have been played in immediate succession, in front of the same crowd. Contemporarily, the term is also used to refer to two games played between two teams in a single day in front of different crowds and not in immediate succession. The record for the most doubleheaders played by a major league team in one season is 44 by the Chicago White Sox in Between September 4 and September 15, 1928, the Boston Braves played nine consecutive doubleheaders – 18 games in 12 days. Most often the game is rescheduled for a day on which the two teams play each other again. Often it is within the same series, but in some cases, may be weeks or months after the original date. On rare occasions, the last game between two teams in that particular city is rained out, and a doubleheader may be scheduled at the other team's home park to replace the missed game. Currently, major league teams playing two games in a day usually play a "day night doubleheader", in which the stadium is emptied of spectators and a separate admission is required for the second game. However, such games are officially regarded as separate games on the same date, rather than as a doubleheader. True doubleheaders are less commonly played.

The Official Baseball Rules used by Major League Baseball (MLB) discuss doubleheaders in section 4.08. The document makes mention of "conventional" and "split" doubleheaders.

In a twi night (short for "twilight night") doubleheader, the first game is played in the late afternoon and, following a break, the second begins at night. Under the Collective Bargaining Agreement (CBA) between MLB and the Major League Baseball Players Association (MLBPA), this is allowed provided the start time of the first game is no later than 5:00 p. m. local time, although they generally start at 4:00 p. m. This type of doubleheader is still used in the minor leagues, or occasionally in MLB as the result of a rainout.

In a split or "day night" doubleheader, the first game is played in the early afternoon and the second is played at night. In this scenario, separate tickets are sold for admission to each individual game. Such doubleheaders are favored by major league organizations because they can charge admission for each game individually, and most often occur as the result of a rainout, where tickets have already been sold to the individual games. Except in special circumstances with the approval of the MLBPA, such as a makeup game resulting from a rainout, scheduling split doubleheaders is prohibited under the terms of the 2002 CBA. Exceptions have occurred; for example, on August 22, 2012, the Arizona Diamondbacks hosted the Miami Marlins in a day night doubleheader, the first doubleheader ever played at Chase Field, which was arranged due to a scheduling error violating another section of the CBA, which prohibits teams from being scheduled to play on more than 20 consecutive days. Since the , the CBA has allowed teams to expand their active roster by one player (currently from 26 to 27 players) for split doubleheaders, as long as those doubleheaders were scheduled with at least 48 hours' notice.

Three instances of a tripleheader are recorded in MLB, indicating three games between the same two teams on the same day. These occurred between the Brooklyn Bridegrooms and Pittsburgh Innocents on September 1, 1890 (Brooklyn won all three); between the Baltimore Orioles and Louisville Colonels on September 7, 1896 (Baltimore won all three); and between the Pittsburgh Pirates and Cincinnati Reds on October 2, 1920 (Cincinnati won two of the three). Tripleheaders are prohibited under the current CBA, except if the first game is the conclusion of a game suspended from a prior date: this would only happen in the extremely rare event when the only remaining dates between teams are doubleheaders, and no single games are left for the suspended game to precede. Near the end of the 2019 season, a Friday doubleheader between the Detroit Tigers and Chicago White Sox was rained out after one of the games started but before five innings were played. As a result, one of the games was made up as part of a doubleheader on Saturday while the other was canceled, as it had no bearing on the postseason. Had the broader use of suspended games been in place in MLB during 2019, it is possible that a tripleheader could have been played on Saturday, beginning with the conclusion of the suspended game.

Under some rulesets, games played as part of a doubleheader last seven innings each instead of the usual nine.

College and minor league baseball typically use seven inning doubleheaders. This applies even in the postseason; in 1994, the first game of the five game Pacific Coast League championship series between Vancouver and Albuquerque was rained out; the two teams played a doubleheader, seven innings each, on the originally scheduled date of the second game. In the minors, if the first game is the completion of a suspended game from a prior day, the suspended game is played to completion (seven or nine innings, whichever it was scheduled to be when it started), and the second game of the doubleheader is seven innings. In leagues which place a runner on second base at the start of extra innings, the rule applies starting in the eighth inning.

After the COVID 19 pandemic delayed the start of MLB's season to July from its original intended start in March, the league announced on July 31 that all doubleheader games would be scheduled for seven innings each during the shortened season, to reduce strain on teams' pitchers. The league and the MLBPA came to an agreement to put this rule in place only for the 2020 season, later extended to the season as well. The season reverted to nine inning doubleheaders. The first major league seven inning doubleheader was played on August 2, 2020, between the Cincinnati Reds and the Detroit Tigers at Comerica Park, with the Reds winning both games.

Some major league feats in a seven inning game were counted as is, while others were not. For example, a shutout was credited when it occurred in a seven inning game; Reds pitcher Trevor Bauer threw the first seven inning shutout under the rule. A no hitter was only credited if the game lasted at least nine innings (i. e. extra innings were played, due to a tie score). Under the 1991 guidelines recognizing major league no hitters, the feat is only officially recognized when a team's pitcher (or pitchers) allows no hits in a minimum of nine innings (that is, records at least 27 outs without allowing a hit). On April 25, 2021, Madison Bumgarner of the Arizona Diamondbacks pitched a complete seven inning game allowing no hits to the Atlanta Braves in the second game of a doubleheader, but did not receive credit for a no hitter. Five pitchers of the Tampa Bay Rays held the Cleveland Indians hitless in a seven inning game, the second game of a doubleheader on July 7, 2021, and also did not receive credit for a no hitter.

National Baseball Hall of Fame inductee Ernie Banks, who spent his entire MLB career with the Chicago Cubs, was known for his catchphrase, "It's a beautiful day for a ballgame   Let's play two! ", expressing his wish to play a doubleheader every day out of his love of baseball.