Each team can still have up to 40 players on major-league contracts, and active rosters are currently typically 26 players, with a limited expansion—to 28 players—from September 1 until the completion of the regular season. A player who is injured or otherwise unable to play is said to be "on disabled list".
The number of active players on the field during any one moment in time varies depending on several factors, most notably the state of the game. If there is no issue at hand other than keeping things interesting, managers will often choose to leave their benches empty rather than risk disrupting the action by replacing an outmanned batter or pitcher. However, if there is a need for reinforcement from the bullpen or the batting order, one or more players will usually be removed from duty.
In addition to those who are actively hitting or pitching, baseball has always had a large number of men in minor-league camps waiting for a chance to prove themselves. Most minor leaguers spend some time on an active roster each year, but many never make it above Class A ball due to injuries or poor performance. Some players never advance beyond that level; others continue to rise through the system until they find a spot with a major league club.
During a regular season, a team's 26-man roster represents its entire roster of active big league players from Opening Day through Aug. 31, as well as during the postseason. All teams must carry 28 players from September 1 through the completion of the regular season. A club can have only one player on the disabled list at any time.
The number of players that a team carries is determined by the league office and is based on several factors, such as the number of games in a season and the length of the season. For example, since the season consists of approximately six months, each team normally carries between 130 and 140 players over the course of a year. In addition, some major league clubs carry their top three starters and their closer in separate games, which increases the total number of players they carry to 137 or 138.
In the National League, where there are typically more pinch-hitters than in the American League, most teams carry 13 pitchers and 99 position players. The Chicago Cubs and San Francisco Giants carry an equal number of players (104) because they play in so many games that they do not need more than that.
In the AL, where teams tend to have more hitters than in the NL, most teams carry 14 pitchers and 95 position players.
At any given moment, a Major League Baseball club may have up to nine players on the field. The club roster might have up to 25 regular players. Furthermore, there may be as many as 14-15 players that are not currently participating for one reason or another. These include injured players who will not return until they are healed, players working their way back from injuries, and even some non-active managers who stay in MLB offices but do not participate in games.
The total number of players on the field at one time is therefore at most 29. This includes the two teams of nine players each as well as the manager and umpires. A team can have as many as four pitchers active at any given time.
In the National Football League (NFL), the maximum number of players on the field at one time is 32. The NFL limit includes all members of the football team as well as two "assistants" coaches who help direct the offense and defense, respectively. They cannot be replaced if they are injured nor can they return to the game after being disqualified. Coaches are considered official personnel of their respective teams; however, since they are employed by the individual team's headquarters instead of by the league office, they do not count against the roster limit.
In the NBA, the maximum number of players on the court at one time is 33.
These coaches have 3-8 more pitchers on their roster than other travel teams.
A current roster The 25-player active roster limit was included in the first collective bargaining agreement between the major leagues and the Major League Baseball Players Association in 1968. Since 1977, clubs have been required to have at least 24 players on their active rosters.
Clubs are not restricted to carrying a certain number of pitchers on their 26-man roster, and clubs normally roster 12 to 13 pitchers and 13 to 14 position players (for a total of 26 active players), however the breakdown fluctuates from team to team during the season. A club's pitching staff is made up of three members each; a starting pitcher, a relief pitcher, and a swing man (or long reliever). In addition, there is a fourth type of pitcher: a shutout pitcher.
In 2014, there were 32 starters in Major League Baseball who had pitched at least one inning in some stage of the season. Of these 32 pitchers, seven had won more than one game (1.9 wins per starter), eight had lost more than one game (2.7 losses per starter), and 17 were winless (4.6 losses per starter). The average winning percentage for these 32 pitchers was 456.
In 2013, there were 31 starters in Major League Baseball who had pitched at least one inning in some stage of the season. Of these 31 pitchers, six had won more than one game (1.9 wins per starter), seven had lost more than one game (2.7 losses per starter), and 18 were winless (4.7 losses per starter). The average winning percentage for these 31 pitchers was 454.