Coca-Cola Park in Allentown, Pennsylvania, home of the Lehigh Valley IronPigs, the Triple-A affiliate of the Philadelphia Phillies

Triple-A (officially Class AAA[1]) has been the highest level of play in Minor League Baseball in the United States since 1946. Currently, two leagues operate at the Triple-A level, the International League (IL) and the Pacific Coast League (PCL). There are 30 teams, one per each Major League Baseball (MLB) franchise, with 20 in the IL and 10 in the PCL. Triple-A teams are generally located in smaller cities as well as larger metropolitan areas without MLB teams, such as Austin, Jacksonville, Columbus, and Indianapolis. Four Triple-A teams play in the same metro areas as their parent clubs.[notes 1]

All current Triple-A teams are located in the United States; before 2008, some Triple-A leagues also fielded teams in Canada,[2] and from 1967 to 2020 the Mexican League was classified as Triple-A. Reasons for the relocation of these teams were solely because of costs and attendance. Other than the current two Triple-A leagues, only three other leagues have ever held the classification.


Jackie Robinson, then with the Triple-A Montreal Royals in July 1946

Prior to 1946, the top level of Minor League Baseball was Double-A, which had been established in 1912.[3][4]: 236  The Triple-A classification was created before the 1946 season, and began with all three leagues then in Double-A moving up to the new level:[4]: 15 

This structure persisted for the next 75 years with only a few changes:

The IL, PCL, and Mexican League continued as Triple-A leagues until Major League Baseball reorganized the minor leagues prior to the 2021 season. At that time, the IL and PCL were temporarily renamed Triple-A East and Triple-A West, respectively. The Mexican League continues to operate, independently. Following MLB's acquisition of the rights to the names of the historical minor leagues, they announced on March 16, 2022, that the leagues would once again be called the International League and the Pacific Coast League, effective with the 2022 season.[6]


While all current and the majority of past Triple-A teams have been located in the United States, Triple-A teams have also been based in:[4]: 104–106 


Further information: Major League Baseball rosters

Players of the Triple-A Nashville Sounds in August 2019

The main purpose of Triple-A teams is to prepare players for the major leagues. In 2010, ESPN wrote:[7]

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.[7]

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.[7]

Most, if not all, of the players on an MLB team's expanded roster who are not currently on the team's active roster are assigned to the team's Triple-A club. Expanded rosters consist of 40 players, while active rosters generally consist of 26 players as of the 2021 season. Most Triple-A teams are located geographically close to their MLB parent club, as activating a Triple-A player as an injury replacement is a common occurrence.

The term "AAAA player," pronounced "four-A" or "quadruple-A," refers to a player who is consistently successful when playing for Triple-A teams, but is not successful at the major league level. The term is usually used derisively and has itself been criticized as flawed.[8][9] Major league team executives and managers disagree whether AAAA players exist.[10]


Teams at this level are divided into two leagues: the International League and the Pacific Coast League. The International League fields teams primarily in the Eastern United States, while the Pacific Coast League fields teams mostly in the Western United States. Each of the 30 major league teams has an affiliation with one Triple-A team in the United States.

Current teams

See also: List of Triple-A baseball stadiums

Triple-A team locations in the United States
Current Triple-A team locations:
  International League
  Pacific Coast League

International League

Main article: International League

Division Team Founded MLB Affiliation Affiliated Since City Stadium Capacity
East Buffalo Bisons 1979 Toronto Blue Jays 2013 Buffalo, New York Sahlen Field 16,600
Charlotte Knights 1976 Chicago White Sox 1999 Charlotte, North Carolina Truist Field 10,200
Durham Bulls 1902 Tampa Bay Rays 1998 Durham, North Carolina Durham Bulls Athletic Park 10,000
Jacksonville Jumbo Shrimp 1962 Miami Marlins 2021 Jacksonville, Florida 121 Financial Ballpark 11,000
Lehigh Valley IronPigs 2008 Philadelphia Phillies 2007 Allentown, Pennsylvania Coca-Cola Park 10,100
Norfolk Tides 1961 Baltimore Orioles 2007 Norfolk, Virginia Harbor Park 11,856
Rochester Red Wings 1899 Washington Nationals 2021 Rochester, New York Innovative 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 10,815
Worcester Red Sox 2021 Boston Red Sox 2021 Worcester, Massachusetts Polar Park 9,508
West Columbus Clippers 1977 Cleveland Guardians 2009 Columbus, Ohio Huntington Park 10,100
Gwinnett Stripers 2009 Atlanta Braves 2009 Lawrenceville, Georgia Coolray Field 10,427
Indianapolis Indians 1902 Pittsburgh Pirates 2005 Indianapolis, Indiana Victory Field 13,750
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
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
Omaha Storm Chasers 1969 Kansas City Royals 1969 Papillion, Nebraska Werner Park 9,023
St. Paul Saints 1993 Minnesota Twins 2021 Saint Paul, Minnesota CHS Field 7,210
Toledo Mud Hens 1965 Detroit Tigers 1987 Toledo, Ohio Fifth Third Field 10,300

Pacific Coast League

Main article: Pacific Coast League

Division Team Founded MLB Affiliation Affiliated Since City Stadium Capacity
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 Baseball Club 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 Space Cowboys 2012 Houston Astros 2021 Sugar Land, Texas Constellation Field 7,500
West Las Vegas Aviators 1983 Oakland Athletics 2019 Summerlin South, 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

Triple-A All-Star Game

Main article: Triple-A All-Star Game

The 2015 Pacific Coast League Triple-A All-Stars

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.[11] 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 was held on the day after the mid-summer Major League Baseball All-Star Game.[12] Such games mark a symbolic halfway-point in the season, despite occurring later than the actual halfway-point of most seasons. Both Triple-A leagues shared 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, were held each year during this break in the regular season.[13]

While the 2021 schedule originally included a three-day All-Star break of July 12–14,[14] this was removed after Opening Day was pushed back one month.[15] Team schedules for the 2021 season were subsequently issued without an All-Star break.[16]

Triple-A Championship

Main article: Triple-A National Championship Game

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.[17] Starting in 2011, the game was held in a different Triple-A city each year.[18] Previous postseason interleague championships include the Junior World Series (1932–34, 1936–62, 1970–71, 1973–74), Triple-A World Series (1983, 1998–2000), and Triple-A Classic (1988–91).

For the 2021 season, in place of the National Championship Game, Minor League Baseball extended the Triple-A regular season to October 3,[19] with league champions determined based on regular-season records through the original end date of the season (September 19 for Triple-A East, and September 21 for Triple-A West).[20] The final 10 games of the season, played after those dates, were deemed the "Final Stretch", with the team posting the best winning percentage during that period (the Durham Bulls, who went 9–1) winning a cash prize.[20][21] Since the 2022 season, the Triple-A National Championship Game has been played between the champions of the International League and the Pacific Coast League.[22] In 2023, the Triple-A Championship game was played at the Las Vegas Ballpark. The winner of this game were the Norfolk Tides.

Pace-of-play initiatives

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.[23] 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.[24] 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.[25]

Timeline of AAA baseball leagues



  1. ^ The Official Professional Baseball Rules Book (PDF). New York City: Office of the Commissioner of Baseball. 2021. p. 10. Retrieved May 1, 2021 – via
  2. ^ "Lynx are outta here: Team sold, will move to U.S." Ottawa Citizen. April 13, 2016. Archived from the original on November 19, 2014. Retrieved September 20, 2014.
  3. ^ "National Commission Grants Minor Leaguers Everything Asked For: Big Moguls of Baseball...Establish Much Wanted Class AA". The Philadelphia Inquirer. January 5, 1912. p. 10. Retrieved April 14, 2021 – via
  4. ^ a b c d e f g h Johnson, Lloyd; Wolff, Miles, eds. (2007). The Encyclopedia of Minor League Baseball (Third ed.). Baseball America. ISBN 978-1932391176.
  5. ^ "Notable Events in American Association History". Triple-A Baseball. Retrieved October 22, 2019.
  6. ^ "Historical league names to return in 2022". Minor League Baseball. March 16, 2022. Retrieved March 29, 2022.
  7. ^ a b c Shelburne, Ramona (September 1, 2010). "John Lindsey waits for his chance". ESPN. Archived from the original on September 6, 2010. Retrieved September 28, 2010.
  8. ^ Stoltz, Nathaniel (April 2, 2008). "Quadruple-A and the Garbage Player Phenomenon: An Exercise in Futility". Bleacher Report. Retrieved April 30, 2022.
  9. ^ Yellon, Al (January 12, 2012). "The Top Ten Quad-A Hitters". Retrieved April 30, 2022.
  10. ^ Goldstein, Kevin (January 11, 2012). "Future Shock: Do Quad-A Players Exist?". Baseball Prospectus. Retrieved April 30, 2022.
  11. ^ Wild, Danny (May 30, 2014). "Voting begins for Triple-A All-Star Game". Minor League Baseball. Archived from the original on August 25, 2014. Retrieved August 19, 2014.
  12. ^ "Omaha Storm Chasers and Werner Park to Host 2015 Triple-A Baseball All-Star Game". Omaha Storm Chasers. Minor League Baseball. March 5, 2014. Archived from the original on March 15, 2014. Retrieved August 19, 2014.
  13. ^ "Durham Lands 2014 Triple-A ASG". Minor League Baseball. February 20, 2013. Archived from the original on March 22, 2014. Retrieved August 19, 2014.
  14. ^ "Bisons Unveil 2021 Playing Schedule, Opening Day Set for April 6 at Sahlen Field". Buffalo Bisons. Minor League Baseball. February 18, 2021. Retrieved February 18, 2021.
  15. ^ Harrigan, Thomas (March 2, 2021). "Triple-A Start Delayed; Alternate Sites to Return". Major League Baseball. Retrieved March 3, 2021.
  16. ^ "Printable Schedule". Worcester Red Sox. Retrieved May 5, 2021.
  17. ^ "Bricktown Showdown To Determine Triple-A Baseball Champion" (PDF). Triple-A Baseball. July 12, 2006. Archived (PDF) from the original on March 4, 2016. Retrieved August 17, 2014.
  18. ^ Hill, Benjamin (February 8, 2011). "Isotopes to Host Triple-A Championship". Minor League Baseball. Archived from the original on August 19, 2014. Retrieved August 17, 2014.
  19. ^ Heneghan, Kelsie (July 1, 2021). "Playoffs return to the Minor Leagues". Retrieved July 1, 2021.
  20. ^ a b Richard, Kevin (July 14, 2021). "MiLB turns Triple-A extended season to tourney–kinda". Retrieved July 15, 2021.
  21. ^ "Durham claims Triple-A Final Stretch championship". October 4, 2021. Retrieved October 4, 2021.
  22. ^ "Las Vegas to Host Inaugural Triple-A Triple Championship Weekend". Minor League Baseball. May 3, 2022. Retrieved May 3, 2022.
  23. ^ Jackson, Josh (January 15, 2015). "Triple-A, Double-A to Implement Pitch Clock". Archived from the original on April 17, 2015. Retrieved April 20, 2015.
  24. ^ "MiLB announces pace-of-play rules for 2018". March 14, 2018. Archived from the original on March 15, 2018. Retrieved March 15, 2018.
  25. ^ "MiLB announces pace-of-play rules for 2019". March 29, 2019. Archived from the original on March 29, 2019. Retrieved March 29, 2019.