3.93 to 3.3 wins per team, not as big of gap when looking at the big picture. It's just easy to say top 5 of Big 10 to make them look better than add in all the **** at the bottom of the conference. Gotta love cherry picking.
Top 5 teams of each conference is 47 to 31. Just to help you out I'm dropping off all the really bad teams for the Big12 as the bottom 5 only contributed 2 wins. Plus only about 5-7 teams go a year from the conference anyway. So that is 9.4 WPY to 6.2 WPY for the top 5 of each conference.
Everyone knows the Big12 is really bad in the NCAA tournament over the last 5 years. I just didn't realize it was this bad.