A Split season is a system by which a league decides that participation in its postseason will be by teams who do well in one of the two halves of the season, instead or in addition to those that do well in the season overall. In practice, leagues that adopt the system select a certain date in mid-season at which point teams with the best records will clinch a postseason slot. They then reset the clock, so to speak, with all teams starting the second part of the season on an equal footing and with a chance to claim one of the remaining postseason slots. Teams that win both halves can be granted a bye in the first round of the postseason (which encourages a team that has already clinched a postseason slot to continue to be competitive in the second half), or a system can be designed to designate another team to claim the second postseason slot.
Split seasons are typically used in the minor leagues. Their purpose is to maintain fan interest, especially for teams that start the season poorly, as they can always rescue a season by playing well in the second half. However, the design of split season systems often leads to incongruities, with teams with poor overall records qualifying for the post-season while others who have played consistently well all year are left out.
In Major League Baseball, a split season has been used only once since 1900, after the 1981 strike. See 1981 Split Season Schedule. However, there has been talk in the late 2010s of introducing such a system for similar reasons as those invoked in the minor leagues that use it. The 1892 season of the National League, following the merger with the American Association, was also played as a split-season with the winners of the two halves meeting in the "World's Championship Series."
- Bob Nightengale: "Things we'd change in sports: Want more MLB drama? Adopt a split-season schedule", USA Today, March 6, 2019.