A regular season and post season championship for a conference with six teams. Weak
The IAC has always tried to mimic what the Ivy League does. They don't even have a post season 4 team play-off for the football season.
I tried to dig up some findings from the old laxpower website. Personally I don't care who win the regular season "paper" championship, I think most players, coaches and parents are about who wins at the end of May.
2010: Landon IAC outright champion
2011: Prep IAC outright champion
2012: Landon IAC outright champion (side note it was after the 2012 season the IAC headmasters brought back the co championship no-sense "everyone is a winner mentality)
2013: Georgetown Prep regular season champion / St. Stephens IAC playoffs
2014: Landon and Georgetown prep tied for the regular season championship / Georgetown Prep wins IAC playoffs (Coach Giblin retires from Prep after this season)
2015: Landon outright regular season and IAC playoff champion
2016: Bullis outright regular season and IAC playoff champion
2017: Landon outright regular season and IAC playoff champion
2018: Landon wins regular season paper championship / Bullis wins the IAC playoff championship
2019: Prep wins regular season paper championship / Bullis wins the IAC playoff championship (Prep doesn't even make it to the IAC finals in 2019)
2020: NO SEASON
2021: fingers crossed there is some type of season in April and May for the kids and players.
Hope this gives some perspective.