|Founded||April 18, 1984|
|Country|| United States |
|Number of teams||15|
|Last champions||Milwaukee Wave |
The National Professional Soccer League was a professional indoor soccer league in the US and Canada. It was originally called the American Indoor Soccer Association.
In November 1983, a Kalamazoo, Michigan-based group called Soccer Leagues Unlimited unveiled a plan for an indoor league composed exclusively of American players. The group's president, Bob Lemieux (later AISA commissioner), announced that Kalamazoo, Fort Wayne, Indiana, and Springfield, Illinois, were on board in what was he said was intended to be a sort of farm system, or developmental league, for the well established Major Indoor Soccer League. He added that groups in Indianapolis, Peoria, and Michigan cities, Saginaw and Flint; Kentucky cities, Lexington and Louisville; Ohio cities, Columbus Toledo and Dayton; Erie, PA; and Green Bay, Wisconsin, were all interested in joining the league.
Officially starting on April 18, 1984, the American Indoor Soccer Association's charter franchises were Chicago, Milwaukee, Kalamazoo and Fort Wayne; however, a Fort Wayne team did not materialize until the league's third season. Three other teams, Louisville, Canton and Columbus, all joined the league before the first season began in November 1984.
In 1990, the league changed its name to the National Professional Soccer League. Over its 17 seasons, a total of 30 franchises in 32 cities were part of the league at one time or another. During the summer of 2001, the league disbanded and the six surviving teams formed the second incarnation of the Major Indoor Soccer League.
When the league began in 1984, game rules were almost identical compared to the larger and more popular Major Indoor Soccer League. Beginning with the 1988–89 season, the AISA changed their scoring system. Goals were now worth 1, 2, or 3 points depending upon distance or game situation. Basically, all non-power play goals scored from inside the yellow line were worth 2 points while non-powerplay goals from outside the yellow line (50 feet from the goal line) were worth 3 points. Any power play goal was worth 1 point, as was any goal scored during a penalty shootout. Before the 1994–1995 season, the three-point line was changed to a 45-foot arc. Eventually, power play goals were worth either two or three points, but penalty shootouts were still kept at one point.
Champions by season
|1984–85||Canton Invaders||Louisville Thunder||3–1|
|1985–86||Canton Invaders||Louisville Thunder||3–0|
|1986–87||Louisville Thunder||Canton Invaders||3–2|
|1987–88||Canton Invaders||Ft. Wayne Flames||(Challenge Cup)|
|1988–89||Canton Invaders||Chicago Power||3–2|
|1989–90||Canton Invaders||Dayton Dynamo||3–1|
|1990–91||Chicago Power||Dayton Dynamo||3–0|
|1991–92||Detroit Rockers||Canton Invaders||3–2|
|1992–93||Kansas City Attack||Cleveland Crunch||3–2|
|1993–94||Cleveland Crunch||St. Louis Ambush||3–1|
|1994–95||St. Louis Ambush||Harrisburg Heat||4–0|
|1995–96||Cleveland Crunch||Kansas City Attack||4–2|
|1996–97||Kansas City Attack||Cleveland Crunch||4–0|
|1997–98||Milwaukee Wave||St. Louis Ambush||4–1|
|1998–99||Cleveland Crunch||St. Louis Ambush||3–2|
|1999–2000||Milwaukee Wave||Cleveland Crunch||3–2|
|2000–01||Milwaukee Wave||Philadelphia KiXX||3–0|
|Canton Invaders → Columbus Invaders → Montreal Impact||5||84–85, 85–86, 87–88, 88–89, 89–90||86–87, 91–92|
|Cleveland Crunch||3||93–94, 95–96, 98–99||92–93, 96–97, 99–00|
|Milwaukee Wave||3||97–98, 99–00, 00–01||–|
|Atlanta Attack → Kansas City Attack||2||92–93, 96–97||95–96|
|Louisville Thunder||1||86–87||84–85, 85–86|
|Tulsa Ambush → St. Louis Ambush||1||94–95||93–94, 97–98, 98–99|
|Dayton Dynamo → Cincinnati Silverbacks||0||–||89–90, 90–91|
|Fort Wayne Flames||0||–||87–88|
- Slater, Jim (November 4, 1983). "Ft. Wayne Will Be Charter Member in New Professional Soccer League". The Star Press. p. 21. Retrieved 20 June 2017 – via newspapers.com.
- "Soccer league planned". Southern Illinoisan. April 19, 1984. p. 15. Retrieved 20 June 2017 – via newspapers.com.
- "Canton wins final AISA crown". Milwaukee Sentinel. April 27, 1990. p. 5B. Retrieved 2012-05-04.
- "SOCCER: ROUNDUP; Rivaldo Gets Hat Trick; Barcelona Earns Victory". New York Times. August 9, 2001. Retrieved 2012-04-29.
- Bunch, Ken (July 11, 1988). "AISA adds franchises, MISL groups may apply". Milwaukee Sentinel. p. B1. Retrieved 2012-05-04.
- Lewis, Michael (2017-04-11). "Dr Joe Machnik: American soccer's renaissance man". The Guardian. ISSN 0261-3077. Retrieved 2017-08-05.