This is something that I've noticed for a while, and for some reason, have not really told anyone else until now. This fanpost really is just to point out a very interesting stat.
I'll cut to the chase. Here's the trend.
For the last 6 straight years, EXACTLY ONE defending Final Four team has returned to the Final Four the following year, and never was it the defending national champion.
2007: Florida, Ohio State, UCLA, Georgetown
Florida wins, UCLA returns
2008: UCLA, Kansas, Memphis, North Carolina
Kansas wins, North Carolina returns
2009: North Carolina, Michigan State, Villanova, Connecticut
North Carolina wins, Michigan State returns
2010: Michigan State, Duke, Butler, West Virginia
Duke wins, Butler returns
2011: Butler, Kentucky, Connecticut, VCU
Connecticut wins, Kentucky returns
2012: Kentucky, Kansas, Ohio State, Louisville
Kentucky wins, Louisville returns
2013: Louisville, Syracuse, Wichita State, Michigan
So if it continues, it means Louisville will not repeat as a defending Final Four team and exactly one of Syracuse, Wichita State or Michigan will be back.
Is it just a coincidence or something more?