Triple-A or Class AAA is the highest level of play in Minor League Baseball in the United States and Mexico. Before 2008, Triple-A leagues also fielded teams in Canada. A total of 30 Triple-A teams play in the Triple-A East and Triple-A West, with 20 teams in the East and 10 teams in the West. Triple-A teams are typically located in large metropolitan areas that do not have Major League Baseball teams, such as Austin, Jacksonville, Columbus, and Charlotte.
The Triple-A classification was created before the 1946 season. Prior to then, the top level of the minors had been designated as Double-A since 1912. The modern Double-A classification also dates to 1946, when the former Class A1 level was renamed.
Triple-A teams' main purpose is to prepare players for the Major Leagues. ESPN wrote in 2010:
Winning is nice, but secondary. It's much more important for a young prospect like outfielder Xavier Paul to get regular at-bats against lefties, or work on dropping down sacrifice bunts with a runner on first, than it is to take three of four from the Portland Beavers.
Both young players and veterans play for Triple-A teams:
There are the young prospects speeding through the organization on the fastest treadmill, the guys who used to be young prospects who are in danger of topping out in Triple-A, the 30-somethings trying to get back to the majors after an injury or a rough patch, and the guys just playing a few more seasons because someone still wants them and they still want to.
Players on the 40-man roster of a major league team are eligible for promotion to the major league club once the major league roster expands on September 1 (though teams will usually wait until their affiliates' playoff runs are over, should they qualify). For teams in contention for the postseason, these players create the flexibility needed to rest regular starters in late regular-season games. For those not in contention, using such players lets the teams evaluate them under game conditions.
Teams at this level are divided into two leagues: Triple-A East and Triple-A West. The Triple-A East fields teams primarily in the Eastern United States, while the Triple-A West fields teams mostly in the Western United States. Each of the 30 Major League Baseball teams has an affiliation with one Triple-A team in the United States.
For much of the 20th century, professional baseball consisted of three affiliated Triple-A leagues: the International League, Pacific Coast League, and American Association. The International and Pacific Coast Leagues lasted until the 2021 reorganization of the minor leagues, while the American Association disbanded in 1997 and its teams were divided among the other two.
|Midwest||Columbus Clippers||1977||Cleveland Indians||2009||Columbus, Ohio||Huntington Park||10,100|
|Indianapolis Indians||1902||Pittsburgh Pirates||2005||Indianapolis, Indiana||Victory Field||14,230|
|Iowa Cubs||1969||Chicago Cubs||1981||Des Moines, Iowa||Principal Park||11,500|
|Louisville Bats||1982||Cincinnati Reds||2000||Louisville, Kentucky||Louisville Slugger Field||13,131|
|Omaha Storm Chasers||1969||Kansas City Royals||1969||Papillion, Nebraska||Werner Park||9,023|
|Toledo Mud Hens||1965||Detroit Tigers||1987||Toledo, Ohio||Fifth Third Field||10,300|
|St. Paul Saints||1993||Minnesota Twins||2021||Saint Paul, Minnesota||CHS Field||7,210|
|Northeast||Buffalo Bisons||1979||Toronto Blue Jays||2013||Buffalo, New York||Sahlen Field||16,600|
|Lehigh Valley IronPigs||2008||Philadelphia Phillies||2007||Allentown, Pennsylvania||Coca-Cola Park||10,100|
|Rochester Red Wings||1899||Washington Nationals||2021||Rochester, New York||Frontier Field||10,840|
|Scranton/Wilkes-Barre RailRiders||1989||New York Yankees||2007||Moosic, Pennsylvania||PNC Field||10,000|
|Syracuse Mets||1934||New York Mets||2019||Syracuse, New York||NBT Bank Stadium||11,071|
|Worcester Red Sox||2021||Boston Red Sox||2021||Worcester, Massachusetts||Polar Park||9,508|
|Southeast||Charlotte Knights||1976||Chicago White Sox||1999||Charlotte, North Carolina||Truist Field||10,200|
|Durham Bulls||1980||Tampa Bay Rays||1998||Durham, North Carolina||Durham Bulls Athletic Park||10,000|
|Gwinnett Stripers||2009||Atlanta Braves||1965||Lawrenceville, Georgia||Coolray Field||10,427|
|Jacksonville Jumbo Shrimp||1962||Miami Marlins||2021||Jacksonville, Florida||121 Financial Park||11,000|
|Memphis Redbirds||1998||St. Louis Cardinals||1998||Memphis, Tennessee||AutoZone Park||10,000|
|Nashville Sounds||1978||Milwaukee Brewers||2021||Nashville, Tennessee||First Horizon Park||10,000|
|Norfolk Tides||1961||Baltimore Orioles||2007||Norfolk, Virginia||Harbor Park||11,856|
|East||Albuquerque Isotopes||2003||Colorado Rockies||2015||Albuquerque, New Mexico||Rio Grande Credit Union Field at Isotopes Park||13,500|
|El Paso Chihuahuas||2014||San Diego Padres||2014||El Paso, Texas||Southwest University Park||9,500|
|Oklahoma City Dodgers||1962||Los Angeles Dodgers||2015||Oklahoma City, Oklahoma||Chickasaw Bricktown Ballpark||9,000|
|Round Rock Express||2000||Texas Rangers||2021||Round Rock, Texas||Dell Diamond||11,631|
|Sugar Land Skeeters||2012||Houston Astros||2021||Sugar Land, Texas||Constellation Field||7,500|
|West||Las Vegas Aviators||1983||Oakland Athletics||2019||Summerlin, Nevada||Las Vegas Ballpark||10,000|
|Reno Aces||2009||Arizona Diamondbacks||2009||Reno, Nevada||Greater Nevada Field||9,013|
|Sacramento River Cats||2000||San Francisco Giants||2015||West Sacramento, California||Sutter Health Park||14,014|
|Salt Lake Bees||1994||Los Angeles Angels||2001||Salt Lake City, Utah||Smith's Ballpark||14,511|
|Tacoma Rainiers||1960||Seattle Mariners||1995||Tacoma, Washington||Cheney Stadium||6,500|
The Triple-A All-Star Game was a single game held between the two affiliated Triple-A leagues--the International League and the Pacific Coast League. Each league fielded a team composed of the top players in their respective leagues as voted on by fans, the media, and each club's field manager and general manager. The event took place every year since 1988 when the first Triple-A All-Star Game was played in Buffalo, New York. Prior to 1998, a team of American League-affiliated Triple-A All-Stars faced off against a team of National League-affiliated Triple-A All-Stars.
Traditionally, the game has taken place on the day after the mid-summer Major League Baseball All-Star Game. The game is meant to mark a symbolic halfway-point in the season (though not the mathematical halfway-point which, for most seasons, is usually one month prior). Both Triple-A leagues share a common All-Star break, with no regular-season games scheduled for two days before the All-Star Game itself. Some additional events, such as the All-Star Fan Fest and Triple-A Home Run Derby, take place each year during this break in the regular season.
With the 2021 reorganization of Minor League Baseball, no announcement about the future of the Triple-A All-Star Game has been made.
Beginning in 2006, the annual Triple-A National Championship Game was held to serve as a single championship game between the champions of the International League and Pacific Coast League to determine an overall champion of Triple-A baseball. It was originally held annually at Chickasaw Bricktown Ballpark in Oklahoma City, and known as the Bricktown Showdown. Starting in 2011, the game was held in a different Triple-A city each year. As with the All-Star Game, no announcement about future editions of the game has been made.
As a part of professional baseball's pace of play initiatives implemented in 2015, 20-second pitch clocks entered use at Triple-A stadiums in 2015. In 2018, the time was shortened to 15 seconds when no runners are on base. Other significant changes implemented in 2018 included beginning extra innings with a runner on second base and limiting teams to six mound visits during a nine-inning game. For the 2019 season, the number of mound visits was reduced to five, and pitchers were required to face a minimum of three consecutive batters unless the side is retired or the pitcher becomes injured and is unable to continue playing.