Classification System

The Minor League Classification System organises minor league baseball leagues into different levels.

Following the reorganization of the minor leagues into the Professional Development League in 2021, there are now five levels: AAA, AA, High-A, Low-A and complex-based leagues (replacing the former Rookie League classification).

History

Before 1902, there was a classification system in place in minor league baseball based on team salary limits, which were in turn based on the size of the cities in which the teams played.

In 1902, the National Association of Professional Baseball Leagues was formed and its leagues were divided into four classes; A, B, C, D. The classes were based the total population of all of the league's member cities. The initial breakdowns were:

• A: 1,000,000 and over
• B: 400,000 to 999,999
• C: 200,000 to 399,999
• D: up to 200,000

In 1912, the AA was established as the highest classification. The A1 class was established in 1936 between the AA and A. Class E was established in 1938 as the lowest classification, however there was only class E league, the Twin Ports League in 1943.

In 1946, the classification system was restructured; with AA leagues become AAA and A1 leagues becoming AA and class E was dropped. In 1952, the classification of "Open classification" was established to help the Pacific Coast League become a major league. It was the top classification. In 1958, the Open classification was removed after the National League moved into Los Angeles and San Francisco.

In 1963, the system was radically restructured into four classifications; AAA, AA, A, Rookie. Classification was no longer based on population, but instead assigned. This is considered the start of the modern era of the minor leagues. The Northern League (A) began to play a short-season schedule in 1965, creating a de facto A-Short Season classification.

Some time around 1992, the A and Rookie classes were informally split into two levels, advanced and regular, creating the seven-tiered system which lasted until 2019.

Current system

Another radical restructuring took place after the COVID-19 pandemic wiped out the 2020 minor league season, although it had been in the works before then. The affiliated minor leagues came under the umbrella of Major League Baseball as part of the "Professional Development League", with a number of independent leagues and summer collegiate leagues also brought into the fold as "partner leagues". The Class A classification, which included four de facto levels at that point, was reduced to just two: Class A (also called "Low-A") and Advanced Class A (also called "[[[High-A]]"). Both the Short-Season Class A leagues and the Rookie Class leagues were abolished or transformed into other entities, to be replaced by two Complex Leagues, replacing the former Gulf Coast League and Arizona League. The Mexican League also lost its AAA designation, which had been a fiction in any case as it had been operating largely independently from the rest of Minor League Baseball, but it retained recognition as a sui generis league within the system.

The fallout from this was to reduce the number of affiliated minor league teams and players, and increase the links with alternative professional leagues where undrafted players and those who were released by major league teams but who still wanted to continue their careers domestically could find a home.

See also

• Minor League Reorganization

Further Reading

• John Cronin: "Truth in the Minor League Class Structure: The Case for the Reclassification of the Minors", in The Baseball Research Journal, SABR, Volume 42, Number 1 (Spring 2013). [1]
• Jonathan Mayo: "MLB announces new Minors teams, leagues: New model includes player salary increases, modernized facility standards, reduced travel", February 12, 2021. [2]