From 2000–01 through 2002–03, regional rankings were the sole method for determining ACHA National Tournament bids. The inaugural 2000–01 season featured teams divided into East and West Regions (Michigan was sorted into the East), with the top four from each in February's final ranking invited to nationals. For 2001–02 and 2002–03, the setup was expanded to include East, Central and West Regions, with U-M moved to the Central Region that it would occupy through 2009–10. Under that system, the top two from each region were invited to nationals, along with two wild card teams. In 2003–04, the tournament field was expanded to 12 teams, and a national ranking was introduced. The latter development diminished the importance of the regional rankings, as the national rankings were used to determine nationals bids. Regional champions were still awarded an autobid, however, even if ranked outside of the top 12 nationally. In 2004–05, growth in the number of ACHA women's teams resulted in an increase to four regions - Northeast, Southeast, Central and West - although things reverted to East, Central and West in 2007–08. The 2009–10 season was notable both for the fact that the tournament field was reduced back to eight teams and as the final year of the regional system, which had become largely antiquated as regional champions generally had little issue placing highly in the national rankings.
