In the early years of Major League Baseball, the only limit on the number of players a team could carry was economic. No one could afford to carry more than the minimum number of players needed to get through a season. Since the first seasons included many off days and most teams used only one or two pitchers, 11 or 12 players generally sufficed. Teams could be sure of keeping a player only for the term of his contract. Soon the National League decided that a greater measure of control over players was needed, so it instituted a reserve rule in 1879. This allowed teams to designate five players that other NL teams could not sign. Within a few years, the size of the reserve list was increased to 11, enough to cover all or nearly all of a team's players. The size of the list was gradually increased over the next decade, but except for a 25 man limit included in the 1884 National Agreement between the NL, American Association, and the minor leagues, no rule actually limited the number of players a team could have during the season. Once again economics came into play, though, following the merger of the two major leagues in 1892. Initially, each team was allowed fifteen players. Despite the new monopoly, attendance was falling, and many of the 12 teams in the NL-AA were losing money. In June of that year, a roster limit of 13, one below the reserve limit, was instituted. This had the side effect of allowing the weaker teams to acquire the players cut loose from the stronger teams.
As the sport's economic picture improved, reserve limits were increased, with a new roster limit of 18 being set in 1899. With renewed competition from the American League, a lower limit was made in 1901, but after the two leagues made peace, a new prosperity allowed larger rosters. In 1910, a new scheme was instituted, with teams being allowed to keep as many as 40 players under control during the offseason and the early and late parts of the season. Prior to 1921, this total did not include players on optional assignments. During the heart of the season, though, teams had to reduce their active rosters to 25 players. Adjustments were made from time to time in these limits, depending on competition from the Federal League and economic conditions. Beginning in 1957, teams were required to reduce their active rosters to 28 players by opening day, with the final reduction to 25 players coming 30 days later. Starting 1968, the 25 man limit was in effect from opening day, although teams were allowed to carry 40 players after August 31.
The other significant changes in roster limits came in response to special circumstances. During and following World War II, in order to accomodate players returning from military service, rosters were expanded by 20% for two years. This allowed teams to obey the law requiring them to give servicemen their pre-war jobs back. A similar rule was passed for Korean War veterans. The other major change came following the failure of the bonus rule to limit large expenditures. A first year player draft was instituted, and to allow teams to take advantage of it, an additional reserve list spot was created just for drafted first year players. This rule was in effect from 1962 to 1966.
In 1977, for the first time, a minimum limit was established as part of the collective bargaining agreement between the players and owners. All Major League teams had to maintain at least 24 players on their active rosters. (From 1986-1990, they acted as though the maximum was also 24.) This persisted until 1991, when the minimum became 25, and was reinstituted in 1993.
A detailed listing of roster limits throughout major league history follows.
|1901||NL||16||Cutdown date 6/15|
|AL||15||O/D + 28 days||N/A|
|1904||AL||16||N/A||Cutdown date 6/1|
|1905||AL||17||N/A||Cutdown date 6/15|
|1962-1965||same as||41||including 1 drafted first year player|
|1990||27||O/D-5/1||40||Due to lockout during spring training|
Guide, Spalding Guide, 1900 National League Constitution, 1990 Basic Agreement