Class A was originally the highest level ofMinor 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 toreserve 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 theEastern League and theWestern League—both leagues had eight teams, in cities such asToronto, Ontario;Buffalo, New York;Worcester, Massachusetts;Omaha, Nebraska;Denver, Colorado; andPeoria, 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 theSouthern League) and Eastern League ascended to Double-A.
In 1965, aClass A Short Season designation was created, for teams playing June–September schedules, primarily meant for new players acquired via theamateur draft. TheClass 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 theCOVID-19 pandemic), Class A consisted of theMidwest League andSouth Atlantic League (a newer "Sally League", which been formed in 1963 as theWestern 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 asHigh-A Central andHigh-A East, respectively. They were replaced at the Class A level by three "Low-A" leagues:[9]Low-A West,Low-A East, andLow-A Southeast.[10] These leagues had historically been known as theCalifornia League,Carolina League, andFlorida 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 sectionneeds expansion with: playoff structure prior to the 2021 re-org. You can help byadding to it.(June 2021)
On June 30, 2021, Minor League Baseball announced that the top two teams in each league (based on full-seasonwinning 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]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aWiki_letter_w_cropped.svg)
