Major League Baseball (MLB) is the highest level of play in North American professional baseball and is the organization that operates the National League and the American League. In 2000, the two leagues were officially disbanded as separate legal entities, and all of their rights and functions were consolidated in the commissioner's office.[1] Since that time, MLB has operated as a single league. Composed of 30 teams, MLB is one of the four major professional sports leagues in the United States and Canada.[2]
Each team in the league has a manager who is responsible for team strategy and leadership on and off the field.[3] Assisted by various coaches, the manager sets the line-up and starting pitcher before each game and makes substitutions throughout the game. In early baseball history, it was not uncommon for players to fill multiple roles as player-managers; specifically, they managed the team while still being signed to play for the club.[4] The last player-manager in Major League Baseball was Pete Rose, who began managing the Cincinnati Reds in 1984.[5]
As of the end of the 2023 MLB regular season, the longest-tenured active manager with the same team in Major League Baseball is Kevin Cash, who has led the Tampa Bay Rays of the American League since 2015. The longest-tenured active manager with the same team in the National League is Craig Counsell, who led the Milwaukee Brewers since 2015 until he signed with the Chicago Cubs following the 2023 postseason. The New York Mets, San Francisco Giants, Chicago Cubs, Cleveland Guardians and the Los Angeles Angels will begin the 2024 season with new managers.
Connie Mack holds the Major League Baseball record for most games won as a manager, with 3,731, and most managed with 7,755. The all-time leaders in championships won in the World Series era (1903–present) are Joe McCarthy and Casey Stengel, who each won seven championships with the New York Yankees.[5]