History
When the American Indoor Soccer Association (AISA) began operating in 1984, it was thought of as a minor league, and seemed to think of itself that way.
There were only six teams, all in the Midwest: the Canton Invaders, Chicago Vultures, Columbus Capitals, Kalamazoo Kangaroos, Louisville Thunder, and Milwaukee Wave. The league's season ran from late fall into the winter, avoiding a direct confrontation with the better-established Major Indoor Soccer League (MISL), which played during the late winter and the spring.
Although its lineup of teams was changing constantly, the AISA became the National Professional Soccer League (NPSL) in 1990, signaling a switch to major-league status, leading to direct competition with the MISL for players. At that time, the league had eight franchises: the Atlanta Attack, Canton Invaders, Chicago Power, Dayton Dynamo, Detroit Rockers, Hershey Impact, Illinois Thunder, Milwaukee Wave, and New York Kick.
The MISL, already over-extended, suddenly became the Major Soccer League and moved outdoors. That left the indoor soccer market to the NPSL and, after the Major Soccer League went out of business in 1992, the NPSL was the only top-level professional soccer league, indoor or outdoor, remaining in the country.
The league grew to 15 teams in 1996, but the American appetite for indoor soccer was fading. The 1994 World Cup tournament, held in the United States, moved fans toward outdoor soccer. And soccer purists disliked the NPSL because of the unorthodox scoring system the league had adopted in 1988, awarding 1, 2, or 3 points per goal, depending on the distance of the scoring shot.
In 2001, the NPSL took the name of its former rival, the Major Indoor Soccer League, and basically started over again as a six-team league. The new MISL in 2002 expanded by absorbing two teams from the World Indoor Soccer League, which had gone out of business.
The 2002-2003 season runs from late September through late March.