Minor League Baseball logo
|No. of teams||240|
|Country(ies)|| United States
|Most recent champion(s)||various|
Minor league baseball is a hierarchy of professional baseball leagues in North America that compete at levels below that of Major League Baseball. All of the minor leagues are operated as independent businesses, and many are members of Minor League Baseball, an umbrella organization for leagues that have agreements to operate as affiliates of Major League Baseball. Several leagues, known as independent leagues, do not have any links to Major League Baseball, and thus are not members of organized baseball. Many alumni of independent baseball, however, have worked their way to the major leagues and many former MLBers play in independent baseball. In minor league baseball, many of the highly touted prospects fail to impress, and many players who are not so well known succeed. This is where the phrase "There is no such thing called a sure thing in the minor leagues" is from.
Each league affiliated with Minor League Baseball comprises teams that generally are independently owned and operated, but always, with the exception of the Mexican League, directly affiliated with (and occasionally named after) one major league team through a standardized Player Development Contract (PDC). Major and Minor League teams may enter into a PDC for a two- or four-year term and may reaffiliate at the expiration of a PDC term, though many relationships are renewed and endure for extended time periods. For example, the Omaha Royals (briefly renamed the Omaha Golden Spikes from 1999-2001, but changed back to Royals in 2002) have been the Triple-A affiliate of the Kansas City Royals since the Royals joined the American League in 1969, but the Columbus Clippers changed affiliations for the 2007 season from the New York Yankees to the Washington Nationals, and are now, beginning in 2009, affiliated with the Cleveland Indians. A small number of minor league teams are directly owned by their major league parent club, such as the Springfield Cardinals, owned by the St. Louis Cardinals, and all of the Atlanta Braves' affiliates except for the Myrtle Beach Pelicans. Minor League teams that are owned directly by the major league Club do not have PDCs with each other and are not part of the reaffiliation shuffles that occur every other year.
The purpose of the system is to develop players available to play in the major leagues on demand.
Minor league baseball also goes by the nicknames the "farm system," "farm club," or "farm team(s)" because of a joke passed around by major league players in the 1930s when St. Louis Cardinals' general manager Branch Rickey formalized the system, and teams in small towns were "growing players down on the farm like corn."
Baseball evolved in the mid-to-late 19th century from an amateur pastime into an organized professional sport.
Fully and openly professional baseball teams arose in 1869. The earliest professional association, the National Association of 1871 to 1875, comprised all fully professional teams. This proved unworkable. There was no way to ensure competitive balance, and financially unsound clubs often failed midseason. This problem was solved in 1876 with the formation of the National League, with a limited membership which excluded less competitive and financially weaker teams.
Professional clubs outside the National League responded by forming regional associations of their own. There was a series of ad hoc groupings, such as the New England Association of 1877 and the Eastern Championship Association of 1881. These were loose groups of independent clubs which agreed to play a series of games for a championship pennant.
The first minor league is traditionally considered to be the Northwestern League of 1883 to 1884. Unlike the earlier minor associations, it was conceived as a permanent organization. It also, along with the National League and the American Association, was a party to the National Agreement of 1883. Included in this was the agreement to respect the reserve lists of clubs in each league. Teams in the National League and the American Association could only reserve players who had been paid at least $1000. Northwest League teams could reserve players paid merely $750. This implicitly established the division into major and minor leagues.
Over the next two decades many more minor leagues signed various versions of the National Agreement. Eventually the minor leagues joined together to negotiate jointly.
In the late 1890s, the Western League run by the fiery Ban Johnson decided to challenge the National League's position. In 1900, he changed the name of the league to the American League and vowed to make deals to sign contracts with players who were dissatisfied with the pay and terms of their deals with the National League. This led to a nasty turf war that heated up in 1901 enough to concern Patrick T. Powers, president of the Eastern League, and many other minor league owners.
They worried about the conflict spilling over into their operations. Representatives met at the Leland Hotel in Chicago on September 5, 1901. In response to the National-American battle, they agreed to form the National Association of Professional Baseball Leagues, called the NAPBL, or NA for short. (The NA uses the name Minor League Baseball today.) Powers was made the first president of the NAPBL, whose offices were established in Auburn, New York.
The purpose of the NA at the time was to maintain the independence of the leagues involved. Several did not sign the agreement, and continued to work independently.
In 1903 the dog fight between the American and National Leagues ended in the National Agreement of 1903. The NAPBL became involved in the later stages of the negotiations to develop rules for the acquisition of players from their leagues by the National and the American.
The NA was signed because players were being pilfered from clubs in other leagues with little or no compensation to the teams. The 1903 agreement ensured that teams would be compensated for the players that they had taken the time and effort to scout and develop.
No NA team was required to sell their players, although most did because the cash became an important source of revenue for most teams.
These leagues were still fiercely independent, and the term "minor" was seldom used in reference to them, save by the major-market sports writers. News did not travel far in the days before heavy television and radio, so, while the leagues often bristled at the major market writers descriptions, their viewpoint of the situation in that day was that they were independent sports businesses, no more and no less.
Many baseball writers of that time regarded the greatest players of the minor leagues, such as Buzz Arlett, Jigger Statz, Ike Boone, Buddy Ryan, Earl Rapp and Frank Shellenback, as comparable to major league players.
In 1922 the United States Supreme Court decision which grants baseball a special immunity from antitrust laws had a major effect on the minor leagues. The special immunity meant that the American and National leagues could dictate terms under which every independent league did business.
By 1925 major league baseball crammed down a flat-fee purchase of $5,000 for the contract of any player from an NA league team. This power was leveled primarily at the Baltimore Orioles, then a Triple-A team that had dominated the minors with stars.
Leagues in the NA would not be truly called minor until Branch Rickey developed the first modern farm system in the 1930s. The Commissioner of Baseball, Kenesaw Mountain Landis fought Rickey's scheme, but ultimately the Great Depression drove teams to establish systems like Rickey's to ensure a steady supply of players, because many NA and independent teams could not afford to keep their doors open without the patronage of major league baseball.
The leagues of the NA became subordinate to the major leagues, the first minor leagues. Other than the Pacific Coast League, which under its president Pants Rowland tried to become a third major league in the Western states, the other leagues maintained autonomy in name, with total dependence upon the American and National league in economic and political fact.
Only 25 of the players on a Major League Baseball team's 40-man major league reserve list may be active for the major league club, except from September 1 to the end of the regular season, when teams are allowed to expand their game-day rosters to 40 players. The remaining 15 players are generally either on the disabled list or play at some level of the minor leagues (usually at the AAA or AA level). Players on the 40-man Reserve List are eligible for membership in the Major League Baseball Players Association. The minor league players work at the lower end of major league pay scales and are covered by all rules and player agreements of the players association. Minor league players not on the 40-man Reserve List are under contract to their respective parent Major League Baseball clubs but have no union. They generally work for far less pay as they develop their skills and work their way up the ladder toward the major leagues. Many players have signing bonuses and other additional compensation that can run into the millions of dollars, although that is generally reserved for early round draft picks.
Even though minor league players are paid considerably less than their major league counterparts, they are nevertheless paid for their services and are thus considered professional athletes. Baseball cards refer to "pro record" and "pro seasons" as including both major and minor leagues. For this reason, minor league players generally consider it an insult when someone asks when they're going to "get to the pros". More accurately, a player's aim is to reach "The Show" or the "big leagues."
There are five classifications of Minor Leagues that are affiliated with Major League Baseball: Class AAA (which the Minor Leagues sometimes call "Triple-A"), Class AA (which the Minor League sometimes call "Double-A"), Class A, Short-Season A and Rookie, according to major league rule 51 (a). Short-Season A is a distinct classification and not a subclassification of Class A.
Class A is sub-divided into two subclassifications: Class A-Advanced and Class A (informally referred to, sometimes, as "high A" and "low A" or "fast A" and "slow A"). The Rookie classification is further sub-divided into two subclassifications: Rookie-Advanced and Rookie. Different roster limits and service restrictions apply to the various classifications and subclassifications.
Major league clubs in the modern farm system will enter into PDCs with several teams to develop players at various classifications. Each major league team is required to have one Class AAA and one Class AA affiliate. In addition, each major league team typically has a PDC with one Class A-Advanced team, one other Class A team, two teams from among the Short-Season A and domestic Rookie leagues and a Rookie team in the Dominican Summer League.
Current Class AAA leagues are the International League and the Pacific Coast League, the champions of which meet annually in a single-game Triple-A championship game in Oklahoma City, called the Bricktown Showdown. Current Class AA leagues are the Eastern League, the Southern League and the Texas League. Current Class A-Advanced Leagues are the California League, the Carolina League and the Florida State League. Current Class A leagues (that are not in the Class A-Advanced subclassification) are the Midwest League and the South Atlantic League. Current Short-Season A classification leagues are the New York-Penn League and the Northwest League. Current Rookie-Advanced leagues are the Appalachian League and the Pioneer League. Current Rookie leagues (that are not in the Rookie-Advanced subclassification) are the Arizona League, the Gulf Coast League, the Dominican Summer League and the Venezuelan Summer League.
Major league teams may share a PDC in an arrangement called a "co-op," though no major league teams currently do so.
Major league Rule 56 governs the standard terms of a PDC. Generally, the parent major league club pays the salaries and benefits of uniformed personnel (players and coaches) and bats and balls, while the minor league club pays for in-season travel and other operational expenses.
Affiliations between teams can change for a variety of reasons. Sometimes Major or Minor League Clubs wish to affiliate with a partner that is geographically closer. In recent years, some MLB clubs have attempted to place as many affiliated teams within their Blackout Area, to make scouting and player transfers more convenient and to take advantage of the existing fan base (interest in the parent team builds support for the minor league affiliate and early fan interest in developing minor league players reinforces support for the parent team as "local players" reach the majors). Sometimes a Minor League Club wishes to improve the caliber of players its major league affiliate sends to play there. Sometimes a major league club wishes to improve the facility where it will send its developing players. In even-numbered years, any Major or Minor League club with an expiring PDC may notify Major League Baseball or Minor League Baseball, respectively, of its desire to explore a re-affiliation with a different PDC partner. The Major League Baseball and Minor League Baseball offices then send a list of the corresponding Major and Minor League Clubs seeking new affiliations, and there is a limited period of time in September within which clubs may agree upon new PDCs. If any are left over after this process, the Major League Baseball and Minor League Baseball offices are empowered to assign Major and Minor League clubs to each other.
The longest continuous link between major league and minor league clubs is the link between the Orioles and their Rookie-level Appalachian League affiliate, the Bluefield Orioles, which is now owned by the parent team. The 2008 season marked the 50th anniversary of the start of this link (1958).
This classification currently includes two affiliated leagues: the International League and the Pacific Coast League. Teams are typically in the largest metropolitan areas without Major League Baseball franchises, such as Columbus, OH, Durham, NC, Memphis, TN, and Sacramento, CA. Triple-A leagues usually hold many of the remaining 15 players of the 40-man major league roster whom the major league club has chosen not to play at the major league level. It has recently been referred to as a "spare parts" classification, because frequently a player who is good enough for the majors (especially if he had signed with a team needing someone to play his natural position) is held in reserve at the minor league level for major league emergencies. Some veteran minor league players are informally called "Four A" players, meaning they are generally regarded as more experienced than a Triple-A player on his way up, yet are not talented enough to stay in the major leagues or do not project as having as much growth in their abilities as those who are less experienced. Some of the top prospects might be assigned here if they are not quite ready for the major leagues, with the potential to be called up later in the season.
Players at this level from the 40-man roster of a major league team can be invited to come up to the major league club once the major league roster expands on September 1, although teams will usually wait until their affiliates' playoff runs are over, should they qualify. For teams in contention for a pennant, it gives them fresh players. For those not in contention, it gives them an opportunity to evaluate their second-tier players for the next season under game conditions.
In addition to the two affiliated Triple-A leagues, the Mexican League is classed a Triple-A league, though its clubs do not have PDCs with Major League clubs.
There are currently three leagues in this classification: Eastern League, Southern League, and the Texas League. Teams are usually located in mid-sized cities such as Akron, OH, Birmingham, AL, Frisco, TX, Jacksonville, FL, Midland, TX, and Reading, PA. Some players will jump to the majors from this level, as many of the top prospects are put here to play against each other, rather than against minor and major league veterans in Triple-A. A small handful of players might be placed here to start, usually veterans from foreign leagues with more experience in professional baseball. The expectation is usually that these players will be in the majors by the end of the season, as their salaries tend to be higher than those of most prospects.
Unlike the major league and the Triple-A level, two of the three Double-A leagues have their season divided in to two parts, the Eastern League being the exception. One team may clinch a spot in the playoffs by winning the division in first half of the season, then the teams' records are cleared and another team will also clinch a playoff slot during the second half. Wild cards are used to fill out the remaining teams; usually, four teams qualify for the league playoffs. This system is used at the Class A level as well.
Class A is a classification comprising two subclassifications: Class A-Advanced and Class A. Players usually have less experience or have particular issues to work out; pitching control and batting consistency are the two most frequent reasons for a player to be assigned to Class A baseball. Short-Season A is not a subclassification of Class A.
One level below Double-A, the California League, Florida State League, and the Carolina League remain at a higher level of play. Class A-Advanced teams are generally located in large and mid-size cities such as Port Charlotte, FL, Lynchburg, VA, Rancho Cucamonga, CA, San Jose, CA, Tampa, FL, and Wilmington, DE. This is often a second or third promotion for a minor league player, although a few high first-round draftees, particularly those with college experience, will jump to this level. These leagues play a complete season like Triple-A and Double-A, April through early September. Many of these teams, especially in the Florida State League, are owned by major league parent clubs and use their spring training complexes.
Slightly below Class A-Advanced, full season leagues like the South Atlantic League and Midwest League are a mix of players moving up from the Short-Season A and Rookie leagues, as well as the occasional experienced first-year player. This class of baseball is found in cities including Dayton, OH, Fort Wayne, IN, Greensboro, NC, and Lakewood, NJ.
As the name implies, these leagues play a shortened season, starting in June and ending in early September (thus, there are only a few off-days during the season). Teams in Short-Season A leagues are generally in small to medium-sized cities such as Keizer, OR and Spokane, WA, although exceptions exist—one team is in Vancouver (the only Canadian team currently in the affiliated minor leagues), another is in Everett, Washington a suburb of Seattle, and two are in New York City, each affiliated with one of the city's MLB teams.
Short-season ball consists of the New York-Penn League and Northwest League and is the highest level short-season affiliate for 22 MLB organizations. The remaining eight clubs have their highest level short-season affiliate in either the Appalachian or Pioneer Leagues. In many instances players drafted out of college will begin their careers at this level, while high-school draftees will more often begin their careers in either an Advanced-Rookie or Rookie League.
The late start to the season is designed to allow college players to complete the College World Series, which runs through late-June, before turning professional, give major league teams time to sign their newest draftees, and immediately place them in a competitive league. Players in these leagues are a mixture of newly-signed draftees and second-year pros who weren't ready to move on, or for whom there was not space at a higher level to move up. Second-year pros tend to be assigned to extended spring training until the short-season leagues begin.
For many players, this is the first time they have ever used wooden baseball bats, because aluminum bats are most common in the amateur game, as well as the first time they have played every day for a prolonged basis, as amateur competitions typically regulate the number of games played in a week. Players are permitted to use certain approved composite bats at this classification, to help them make the transition from aluminum to wood bats.
Short-Season A is not a subclassification of Class A. It is a distinct classification.
Leagues in the Rookie classification play a shortened season similar to the Short-Season A classification leagues, starting in June and ending in early September.
Comprising the Appalachian League and the Pioneer League, this level is a mix of new draft picks directly out of high school or college and second-year players. Rookie-Advanced teams are usually in smaller urban areas such as Danville, VA, Greeneville, TN, Ogden, UT, and Orem, UT. For some major league organizations, such as the Milwaukee Brewers, this serves as their highest level short-season affiliate. The Brewers have a team in the Pioneer League, the Helena Brewers, and a team in the Arizona League, the AZL Brewers, but do not have an affiliated club in either the New York-Penn or Northwest Leagues.
The lowest level of Minor League Baseball, the leagues here are also short-season leagues. In the United States, team rosters of the Gulf Coast League and the Arizona League consist of newly-signed draftees and a few players brought in from the Dominican Summer League, Venezuelan Summer League, or Mexican Academy League of the season prior. It is considered a low-pressure learning environment for players, as there are few spectators.
The current minor league structure is largely based on a significant reorganization that occurred before the 1963 season, caused by the club and league contraction of the 1950s and early 1960s.
In 1946, the Triple-A classification was created and it became the highest level of the minors, which formerly was called Double-A. The two Class A1 circuits, the Texas League and the Southern Association, were then designated Double-A, now two rungs below MLB.
Before 1963, the Class A level was a middle- to higher-rung classification. In 1946, Class A consisted of the Eastern League and the original South Atlantic or "Sally" League, and it would soon include the Western League, which folded after the 1958 season, the Central League of 1948-1951, and the Western International League, which would become the Class B Northwest League after 1954. The lower levels of the minors were ranked Classes B through D, in descending order. With the exception of the 1952-1957 Open Classification experiment for the Pacific Coast League, this structure would remain intact through 1962. (see Defunct levels, below)
During the 1962-1963 offseason, the two remaining Triple-A leagues (the International and Pacific Coast leagues) absorbed the four surviving franchises from the defunct American Association. Meanwhile, at the Double-A level and below there were even more significant changes:
Later, in the mid-1960s, the Short-Season Class A designation was created, and the New York-Penn, Northern and Northwest loops moved into that classification.
The Georgia-Florida League disbanded after the 1963 season, while the Northern League played its last year in official minor league baseball in 1971. In 1980, the Western Carolinas League became the modern incarnation of the South Atlantic League.
As part of the 1963 reorganization, Major League clubs increased their commitments to affiliate with minor league teams through Player Development Contracts, outright ownerships, or shared affiliations and co-op arrangements.
The Pacific Coast League, from 1952-1957, was the only minor league to obtain this classification. At this time, the major leagues only extended as far west as St. Louis and as far south as Washington, DC. This classification severely restricted the rights of the major leagues to draft players out of the PCL, and at the time it seemed like the PCL would eventually become a third major league. The PCL would revert back to Triple-A classification in 1958 due to increasing television coverage of major league games and in light of the Dodgers and Giants moving to Los Angeles and San Francisco, respectively. The open classification no longer exists in the major league rules.
The forerunner to the modern Double-A classification, the A1 level existed from 1936 through 1945. In 1936, two Class A circuits, the Texas League and the Southern Association, were upgraded to A1 to signify their continued status as one step below the highest classification, then Double-A, yet a notch above their former Class A peers, the New York-Pennsylvania League and Western League. Ten years later, after World War II, with the minor leagues poised for unprecedented growth, classification terminology was changed. Beginning in 1946, the three Double-A leagues (the American Association and International and Pacific Coast leagues) joined a new classification, Triple-A, and the two A1 leagues became known as Double-A.
Until 1963, there were also Class B, C, and D leagues (and, for half a season, one E league). The Class D of that day would be equivalent to the Rookie level today. The other class designations disappeared because leagues of that level could not sustain operation during a large downturn in the financial fortunes of minor league baseball in the 1950s and 1960s caused by the rise of television broadcasts of major league sports across broad regions of the country. The impact of the Korean War in 1950 caused a player shortage in most cities in class D and C.
A major league team's Director of Player Development determines, in coordination with the coaches and managers who evaluate their talent, in Spring training. Players both from the spring major camp and minor league winter camp are placed at end of the spring training season by the major league club on the roster of a minor league team.
The Director and the General Manager usually determine the initial assignments for new draftees, who typically begin playing professionally in June after they have been signed to contracts.
The farm system is ever-changing: Evaluations of players are ongoing. The Director of Player Development and his managers will meet or teleconference regularly to discuss how players are performing at each level. In addition to personal achievement, injuries, and high levels of achievement by players in the classes above and below all steer a player's movement up and down in the class system.
Players will play for the team to which they are assigned for the duration of that season unless they are "called up," promoted to a higher level; "sent down," demoted to a lower class team in the major league club's farm system; or "released" from the farm system entirely. A release from minor-league level used to spell the end of a minor league player's career. In more modern times, with a more powerful independent baseball system, many players will "park" a career for a season or two in the independent leagues, which are scouted much more heavily. Many will get a second or third look from the major league scouts if they turn their career around in the indies.
There are variations to the Farm System's classes that should be noted:
The umpire is the person charged with officiating the game, including beginning and ending the game, enforcing the rules of the game and the grounds, making judgment calls on plays, and handling the disciplinary actions.
The body responsible for any action related to the training, evaluation, and recommendation for promotion and retention or release of the umpires is the Professional Baseball Umpire Corp. It is an owned subsidiary of the National Association of Professional Baseball Leagues.  The umpires are evaluated by the staff of the PBUC at each mid-season and end of the year. The evaluation is based on the performance of the umpire during the year to then decide if a certain umpire may advance in classification the following season. PBUC holds an annual Evaluation Course every year in March. At this course, the prospective rookie umpires may participate in order to evaluate their umpiring abilities. These are normally the best students from the two professional umpire schools owned and operated by the same entity. The top students who pass the Evaluation Course are going to pursuit their careers in baseball by being recommended for the first openings in the Rookie and Short-A leagues. 
Any student who wants to follow an umpiring career must attend a professional umpire training school. The PBUC recognizes two schools for training the students who want to become professional umpires. These are the Jim Evans Academy of Professional Umpiring and the Harry Wendelstedt Umpire School, both located in Florida. The classes of each school are held in the first part of January through the first part of February, for about five weeks. The instructors at these schools are Major or Minor League former or present umpires. However, the simple attendance of the trainings of these schools does not guarantee that the candidate will also be recommended either to the Course Evaluation either to the openings in the Rookie or Short-Season A league. . Before the umpire development program was created, the Minor League presidents would recruit umpires from the schools. They were being after "sold" from league to league by word of mouth through the various league presidents.  The umpire development program first started in 1964, when it was decided that a method of recruitment, training and development for umpires of both Major and Minor Leagues was needed. The Umpire Development Program was founded at Baseball's Winter Meetings in Houston, 1964 and it started operating a year later. The purpose of the program was to recruit more athletic, energetic and dedicated individuals who would also have high morals and integrity standards. In 1968, it was decided that the program needed its own umpire training course which would be held each year. The first "Umpire Specialization Course" was held in St. Petersburg, Florida the following year. 
Nowadays, the candidates for a job in professional umpiring must meet several requirements in order to be considered. An applicant must have a High School Diploma or a G.E.D., must be athletic and also must have 20/20 vision, no matter if they wear glasses or contact lenses.  They must also have good communication skills, good reflexes and coordination as well as they must have been following the trainings provided by one of the two professional umpire schools. Apart from this, the future umpires must be quick thinkers, confident and must have common sense. They must have a neat appearance and it is mandatory that they have a thorough knowledge of the rule book. The candidates must show a keen desire to succeed in this career.
Minor League Baseball, formerly the National Association of Professional Baseball Leagues and also known in the past as NAPBL, National Baseball Association, and NA, is the organization which oversees the governing and organization of minor league baseball in North America.
The NAPBL formed in 1901 as a reaction to the warfare going on between the National League and the American League. The presidents of the other professional baseball leagues then in existence were concerned that the two "major leagues" and their continuing pirating of players and even whole teams were a threat to the existence of professional baseball in the United States and Canada.
At the time, the National and American Leagues were not seen as "major leagues", but only as leagues which existed in larger cities. Led by Patrick T. Powers, then-president of the Eastern League, the larger minor leagues then in existence banded together to control their own fates.
Powers' idea was that, instead of going head-to-head with the National and American Leagues, the other leagues should set standard rules for officiating, player drafts, contracts, and location of teams. Fourteen leagues (the Eastern League, Western League, New England League, New York State League, Pacific Northwest League, Southern Association, Three-I League, Carolina League, Connecticut League, Cotton States League, Iowa-South Dakota League, Michigan State League, Missouri Valley League and Texas League) signed the agreement to begin play under the new rules effective with the 1902 season.
Many leagues refused to join, fearing that the creation of the NA was just an attempt at forming another "major" league, and that its rules and territorial limits would interfere with their independence. When that fear failed to materialize, however, more and more leagues joined the NA until, within a few years, it consisted of thirty-five leagues.
Patrick Powers resigned his presidency of the NA in 1909 in order to concentrate on his private business interests. The Association managed to maintain its original purpose for about twenty years, but during the Great Depression, many leagues began to fold, and the Association needed to look for more funding in order to keep minor league baseball going.
This funding came from the same major league teams which the NA had been created to protect itself from. Starting in 1931, major league teams began affiliation agreements with minor league teams. Branch Rickey, president of the St. Louis Cardinals, was the architect of the system which exists today, in which most minor league teams are affiliates of major league teams, supplying the Majors with development of younger players in exchange for financial support from the major league teams with which they are affiliated.
Because so many professional players went to fight during World War II, the number of teams and leagues decreased even more until the end of the war. From 1945, when there were only twelve leagues left in the NA, there were fifty-nine in 1949. That number has decreased until, today, there are seventeen.
In 1999, the NAPBL formally changed its name to Minor League Baseball.
Minor League Baseball still governs the minor league system, although there are several independent leagues which do not fall under the group's aegis.
Leagues with a * are sublassified as Class A-Advanced leagues.
Leagues with a * are sublassified as Rookie-Advanced leagues.
These leagues are not affiliated with Major League Baseball or Minor League Baseball and operate as fully independent professional leagues
Minor league baseball is a level of professional baseball in North America. It is made up a many different teams which play in many leagues and levels of ability. Minor league teams are used by Major League teams to have a place to put their players who they do not feel are good enough to play in the Major League yet.
There are several different levels of ability in the Minor Leagues, these levels are (in order from lowest to highest):
Once a player has shown he is good enough to play in one level of the minor leagues, he is usually moved up to a higher, more difficult level, until he is finally able to play in the Major Leagues. This way players are able to get better at baseball before having to play against tougher opponents. Almost all players in the Major Leagues had to play in the minor leagues first in order to become good enough to play in the Major Leagues.
Sometimes, Major League players who are have been hurt will play a few games in the minor leagues before playing in the Major Leagues again, in order to see if they feel good enough to start playing again.
There are also other professional baseball leagues that Major League teams do not use to as a place put their players. These are known as "Independent Leagues". In these leagues players do not go to higher or lower levels of ability.