Class A was originally the highest level of Minor League Baseball, beginning with the earliest classifications, established circa 1890.[2]: 15 Teams within leagues at this level had their players' contracts protected and the players were subject to reserve clauses.[2]: 15 When the National Association of Professional Baseball Leagues – the formal name of Minor League Baseball – was founded in 1901, Class A remained the highest level, restricted to leagues with cities that had an aggregate population of over a million people.[3][4][5] Entering the 1902 season, the only Class A leagues were the Eastern League and the Western League—both leagues had eight teams, in cities such as Toronto, Ontario; Buffalo, New York; Worcester, Massachusetts; Omaha, Nebraska; Denver, Colorado; and Peoria, Illinois.[2]: 187 Leagues operating within less populated areas were classified as Class B, Class C, or Class D.
The hierarchy of Triple-A through Class D continued until Minor League Baseball restructured in 1963, at which time Classes B through D were abolished, with existing leagues at those levels reassigned into Class A, while the South Atlantic League (renamed as the Southern League) and Eastern League ascended to Double-A.
In 1965, a Class A Short Season designation was created, for teams playing June–September schedules, primarily meant for new players acquired via the amateur draft. The Class A-Advanced designation was established in 1990, between Class A and Double-A in the minor league hierarchy.[6] Class A and Class A Short Season were considered independent classifications, with Class A having "Full-Season" and Advanced sub-classifications, per the rules governing baseball's minor leagues.[7] The overall hierarchy was:
Entering the 2020 minor league season (which was not played due to the COVID-19 pandemic), Class A consisted of the Midwest League and South Atlantic League (a newer "Sally League", which been formed in 1963 as the Western Carolinas League). Prior to the 2021 season, MLB restructured the minor leagues, eliminating Class A Short Season and discontinuing the use of all historical league names within Minor League Baseball.[8] The Midwest League and South Atlantic League were reclassified as "High-A" leagues, and operated during 2021 as High-A Central and High-A East, respectively. They were replaced at the Class A level by three "Low-A" leagues:[9]Low-A West, Low-A East, and Low-A Southeast.[10] These leagues had historically been known as the California League, Carolina League, and Florida State League, respectively, and had previously operated at the Class A-Advanced level.[8] These three leagues operated with Low-A naming for the 2021 season. Following MLB's acquisition of the rights to the names of the historical minor leagues, MLB announced on March 16, 2022, that the leagues would revert to their prior names, effective with the 2022 season.[11] MLB also discontinued use of "Low-A" in favor of Single-A.[11]
This section needs expansion with: playoff structure prior to the 2021 re-org. You can help by adding to it. (June 2021)
On June 30, 2021, Minor League Baseball announced that the top two teams in each league (based on full-season winning percentage, and regardless of division) would meet in a best-of-five postseason series to determine league champions.[12]
Florida State League
Carolina League
California League![[icon]](https://akarinohon.com/text/taketori.cgi/en.wikipedia.org/wiki/File:Wiki_letter_w_cropped.svg@.25_Remington){kind=small}
