|No. of teams||8|
|Long Island Ducks (2019)|
|Most titles||Somerset Patriots (6)|
The Atlantic League of Professional Baseball (ALPB) is a professional baseball league based in the United States. It is an official Partner League of Major League Baseball. It is located in the Mid-Atlantic and Southeastern United States, especially the greater metropolitan areas of the Northeast megalopolis and the Piedmont Triad and Charlotte Metrolina regions of North Carolina. League offices are located in Lancaster, Pennsylvania.
The Atlantic League operates in cities not served by Major League Baseball (MLB) or Minor League Baseball (MiLB) teams; most of its teams are within suburbs and exurbs too close to other teams in the organized baseball system to have minor league franchises of their own. The Atlantic League requires cities to have the market for a 4,000 to 7,500-seat ballpark and for the facility to be maintained at or above Triple-A standards. When Atlantic League professionals are signed by MLB clubs, they usually start in their Double-A or Triple-A affiliates.
The league uses a pitch clock and limits the time between innings in an effort to speed up the game. In 2019, the Atlantic League began a three-year partnership with Major League Baseball allowing MLB to implement changes to Atlantic League playing rules, in order to observe the effects of potential future rule changes and equipment. In 2020, the Atlantic League, together with the American Association, the Frontier League, and the Pioneer League, expanded this agreement to become an official MLB Partner League.
In 1998, the Atlantic League of Professional Baseball played its inaugural season, with teams in Bridgewater, Newark, and Atlantic City, New Jersey; Nashua, New Hampshire; Newburgh, New York; and Bridgeport, Connecticut. The creation of the league was the result of the New York Mets' objection to Frank Boulton's proposal to move the former Albany-Colonie Yankees because of its territorial rights to the region. Boulton, a Long Island native, decided to create a new league that would have a higher salary cap for its players and a longer season than most of the other independent baseball organizations. He modeled the Atlantic League after the older Pacific Coast League, with facilities that exceed AAA-level standards. Boulton also emphasized signing players of Major League Baseball experience for all Atlantic League teams, raising the level of play above other independent leagues.
In 2010, the league announced that it would be expanding to Sugar Land, Texas and adding its first franchise not located in an Atlantic coast state. The Sugar Land Skeeters began play in 2012. In 2010, amid financial struggles, the Newark Bears moved from the Atlantic League to the Can-Am League, leaving the Bridgeport Bluefish and Somerset Patriots as the only teams remaining from the league's inaugural season. In the summer of 2013, then-ALPB President Frank Boulton announced that he would be resigning so that he could devote more time to operating the Long Island Ducks. He was replaced by longtime high-ranking Major League Baseball executive Rick White. On July 8, 2015, the Atlantic League began using Rawlings baseballs with red and blue seams, virtually unused in the sport since the American League swapped the blue in their seams for red in 1934.
On September 1, 2015, the Atlantic League announced conditional approval for an expansion team or a relocated team to play in New Britain, Connecticut for the 2016 season. On October 21, 2015, the Camden Riversharks announced they would cease operations immediately due to the inability to reach an agreement on lease terms with the owner of Campbell's Field, the Camden County Improvement Authority. The team was replaced by the New Britain Bees for the 2016 season. On May 29, 2016, Jennie Finch was the guest manager for the league's Bridgeport Bluefish, thus becoming the first woman to manage a professional baseball team.
Shortly before the conclusion of the 2017 season, the city of Bridgeport, Connecticut voted to not continue with professional baseball in the city and announced plans to convert The Ballpark at Harbor Yard into a music amphitheater; the Bridgeport Bluefish announced plans to relocate to High Point, North Carolina in 2019 when the construction of a new multipurpose facility in High Point is completed. League officials announced the return of the Pennsylvania Road Warriors, an all road game team, to keep the league at an even eight teams while the Bluefish go inactive for the 2018 season.
The Atlantic League is generally regarded as the most successful and highest level of baseball among independent leagues. Two former Atlantic League players have been inducted into the Baseball Hall of Fame: Tim Raines and Rickey Henderson. Other notable former and future Major League ballplayers who have played in the league include Roger Clemens, Scott Kazmir, Dontrelle Willis, Juan González, Francisco Rodríguez, John Rocker and José Canseco, and several others have coached or managed, including Gary Carter, Tommy John, Bud Harrelson, Gary Gaetti and Sparky Lyle. The Atlantic League has consistently posted higher per game and per season attendance numbers than other independent circuits including the American Association, Can-Am League, and Frontier League.
In 2015, the Atlantic League experienced a watershed moment for independent baseball when it signed a formal agreement with Major League Baseball which put into writing the rules which the ALPB would follow in selling its players' contracts to MLB clubs and their affiliates. This marked the first time that MLB, which has enjoyed a U.S. Supreme Court-granted antitrust exemption since 1922, had made any formal agreement with or acknowledgment of an independent baseball league.
In 2020, due to the COVID-19 pandemic, the league announced that it would be unable to operate for the 2020 season with the current 8 member ballclubs, thereby canceling its season. Several teams (Somerset, York, and Lancaster) did not gain necessary approval from governmental and health officials to open their ballparks to the capacity level necessary for competition. They used their stadiums to host recreational and community-based events, as well as local baseball activities where allowed. Meanwhile, the Long Island Ducks, High Point Rockers, and Southern Maryland Blue Crabs initially attempted to partner with teams from other leagues in order to play a 70-game season from mid-July through the end of September. However, due to ongoing restrictions and capacity limitations, they ultimately decided to suspend all baseball activities for the 2020 season. The only teams that played in 2020 was the Sugar Land Skeeters, who would create a new 4-team independent league in Texas, with all 60 games played at Constellation Field, and the Somerset Patriots, who played weekend games with a second squad called the New Jersey Blasters.
In November 2020, the Atlantic League lost its last charter franchise and its westernmost franchise when both teams became official minor league affiliates. On November 7, the Somerset Patriots announced that they were leaving the league to join the MLB-affiliated Eastern League, where they will replace the Trenton Thunder as the Double-A affiliate of the New York Yankees. Approximately two weeks later, the Houston Astros announced that they had purchased a controlling stake in the Sugar Land Skeeters and, as a result, the Skeeters would become the Astros' Triple-A affiliate and join the Pacific Coast League.
On February 18, 2021, the league announced the addition of the Lexington Legends, previously the Class A South Atlantic League affiliate of the Kansas City Royals, for the 2021 season. The West Virginia Power, also formerly a member of the Class A South Atlantic League, announced their move to the league on February 24, 2021.
In March 2019, the Atlantic League and Major League Baseball reached agreement to test multiple rule changes during the 2019 Atlantic League season:
In April 2019, implementation of two of the changes was delayed:
The tracking system for calling balls and strikes was introduced at the league's all-star game on July 10. In addition to rule changes noted above, additional changes being implemented for the second half of the league's 2019 season are:
The Atlantic League and MLB jointly announced that the former would adopt several additional experimental rules for the 2021 season:
|Lancaster Barnstormers||2003||2005||Lancaster, Pennsylvania||Clipper Magazine Stadium||6,000|||
|Long Island Ducks||1998||2000||Central Islip, New York||Fairfield Properties Ballpark||6,002|||
|Southern Maryland Blue Crabs||2006||2008||Waldorf, Maryland||Regency Furniture Stadium||4,200|||
|York Revolution||2006||2007||York, Pennsylvania||PeoplesBank Park||5,200|||
|Gastonia Honey Hunters||2020||2021||Gastonia, North Carolina||FUSE District Stadium||5,000|||
|High Point Rockers||2018||2019||High Point, North Carolina||Truist Point||4,500|||
|Lexington Legends||2001||2021||Lexington, Kentucky||Whitaker Bank Ballpark||6,994|||
|West Virginia Power||1987||2021||Charleston, West Virginia||Appalachian Power Park||4,500|||
League members Moved to another league
|Aberdeen Arsenal||Bel Air, Maryland||Thomas Run Park||2000||Replaced by the Aberdeen IronBirds (Orioles Class-A affiliate)|
|Atlantic City Surf||Atlantic City, New Jersey||The Sandcastle||1998-2006||Moved to Can-Am League, folded prior to the 2009 season|
|Bridgeport Bluefish||Bridgeport, Connecticut||The Ballpark at Harbor Yard||1998-2017||Folded when they lost the lease on their ballpark; replaced by the High Point Rockers|
|Camden Riversharks||Camden, New Jersey||Campbell's Field||2001-2015||Replaced by the New Britain Bees|
|Lehigh Valley Black Diamonds||Quakertown, Pennsylvania||Quakertown Memorial Stadium||1999-2001||Formerly the Newburgh Black Diamonds (1998), became the first Pennsylvania Road Warriors|
|Nashua Pride||Nashua, New Hampshire||Holman Stadium||1998-2005||Moved to Can-Am League, later relocated to Pittsfield, Massachusetts, folded at the end of the 2011 season|
|Newark Bears||Newark, New Jersey||Bears & Eagles Riverfront Stadium||1998-2010||Moved to Can-Am League, folded prior to the 2014 season|
|Newburgh Black Diamonds||Newburgh, New York||Delano-Hitch Stadium||1998||Became the Lehigh Valley Black Diamonds (1999-2001), which became the first Pennsylvania Road Warriors (2002-2004)|
|New Britain Bees||New Britain, Connecticut||New Britain Stadium||2016-2019||Moved to Futures Collegiate Baseball League; Replaced by the Road Warriors for the 2020 season|
|Somerset Patriots||Bridgewater Township, New Jersey||TD Bank Ballpark||1998-2020||Moved to Minor League Baseball as part of MiLB realignment; became New York Yankees Double-A affiliate.|
|Sugar Land Skeeters||Sugar Land, Texas||Constellation Field||2012-2020||Moved to Minor League Baseball as part of MiLB realignment; became Houston Astros Triple-A affiliate.|
|Bergen Cliff Hawks||East Rutherford, New Jersey||Bergen Ballpark||2000-2011|
|Hammonton Blueberries||Hammonton, New Jersey||Blueberry Field||1998-2000|
|Loudoun Hounds||Ashburn, Virginia||Edelman Financial Field||2012-2016|
|Virginia Beach Neptunes||Virginia Beach, Virginia||Wheeler Field||2016-2017|
The ALPB Championship Series is played as a best-of-five. Numbers in parenthesis denote the number of championships won by a team to that point, when more than one.
|Year||Winner||Runner-up||Result||Championship Series MVP|
|1998||Atlantic City Surf||Bridgeport Bluefish||3-1||Chris Eddy|
|1999||Bridgeport Bluefish||Somerset Patriots||3-0||Duane Singleton|
|2000||Nashua Pride||Somerset Patriots||3-0||D.J. Boston|
|2001||Somerset Patriots||Newark Bears||3-2||Robert Dodd|
|2002||Newark Bears||Bridgeport Bluefish||3-0||Jimmy Hurst|
|2003||Somerset Patriots (2)||Nashua Pride||3-2||Jeff Nettles|
|2004||Long Island Ducks||Camden Riversharks||3-0||Justin Davies|
|2005||Somerset Patriots (3)||Nashua Pride||3-0||Mark DiFelice|
|2006||Lancaster Barnstormers||Bridgeport Bluefish||3-0||Jeremy Todd|
|2007||Newark Bears (2)||Somerset Patriots||3-1||José Herrera|
|2008||Somerset Patriots (4)||Camden Riversharks||3-1||Brandon Larson|
|2009||Somerset Patriots (5)||Southern Maryland Blue Crabs||3-1||Jeff Nettles|
|2010||York Revolution||Bridgeport Bluefish||3-0||Ramón Castro|
|2011||York Revolution (2)||Long Island Ducks||3-1||Vince Harrison|
|2012||Long Island Ducks (2)||Lancaster Barnstormers||3-2||Dan Lyons|
|2013||Long Island Ducks (3)||Somerset Patriots||3-2||John Brownell|
|2014||Lancaster Barnstormers (2)||Sugar Land Skeeters||3-0||Gabe Jacobo|
|2015||Somerset Patriots (6)||Southern Maryland Blue Crabs||3-1||Roy Merritt|
|2016||Sugar Land Skeeters||Long Island Ducks||3-0||Juan Martinez|
|2017||York Revolution (3)||Long Island Ducks||3-0||Telvin Nash / Chase Huchingson|
|2018||Sugar Land Skeeters (2)||Long Island Ducks||3-2||James Russell|
|2019||Long Island Ducks (4)||Sugar Land Skeeters||3-2||Deibinson Romero|
|2020||Season cancelled due to COVID-19 pandemic|
|1998||Atlantic City, New Jersey||The Sandcastle||Atlantic City||6-4|
|1999||Bridgeport, Connecticut||The Ballpark at Harbor Yard||South||8-3|
|2000||Bridgewater, New Jersey||Commerce Bank Ballpark||North||2-0|
|2001||Newark, New Jersey||Bears & Eagles Riverfront Stadium||North||10-0|
|2002||Central Islip, New York||Citibank Park||South||4-1|
|2003||Nashua, New Hampshire||Holman Stadium||South||2-1|
|2004||Camden, New Jersey||Campbell's Field||North||10-8|
|2005||Atlantic City, New Jersey||The Sandcastle||North||9-6|
|2006||Bridgeport, Connecticut||The Ballpark at Harbor Yard||North||4-1|
|2007||Lancaster, Pennsylvania||Clipper Magazine Stadium||North||8-6|
|2008||Bridgewater, New Jersey||Commerce Bank Ballpark||Freedom||8-6|
|2009||Newark, New Jersey||Bears & Eagles Riverfront Stadium||Liberty||7-5|
|2010||Central Islip, New York||Suffolk County Sports Park||Liberty||7-1|
|2011||York, Pennsylvania||Sovereign Bank Stadium||Freedom||7-0|
|2012||Camden, New Jersey||Campbell's Field||Freedom||9-5|
|2013||Waldorf, Maryland||Regency Furniture Stadium||Freedom||2-1|
|2014||Sugar Land, Texas||Constellation Field||Sugar Land||5-3|
|2015||Bridgeport, Connecticut||The Ballpark at Harbor Yard||Freedom||5-1|
|2016||Lancaster, Pennsylvania||Clipper Magazine Stadium||Freedom||3-1|
|2017||Bridgewater, New Jersey||TD Bank Ballpark||Freedom||10-3|
|2018||Central Islip, New York||Bethpage Ballpark||Liberty||4-3|
|2019||York, Pennsylvania||PeoplesBank Park||Freedom||3-3|
|2020||None (season cancelled due to COVID-19 pandemic)|
Freedom Division won the 2019 game in a "homer-off" after the teams were tied at the end of nine innings.
Some Atlantic League players have come from, or advanced to, the higher ranks of Major League Baseball. Some have resurrected their careers and returned to the majors, while others played in the independent league during the start or end of their careers.  The following is a list of some of those players: