I think there is some overall achievement required and some recency bias (what have you done for me lately?).
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There are 6 Blue Bloods in the Modern Era. Only UNC, Duke, UConn, Ville, Kentucky, & Nova have won 3 or more titles in this era.
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Indiana, Kansas, and UCLA are historical blue bloods but have paled in the modern era with less than 3 titles. Florida and Michigan State are also Pale Blue.
There are 4 other programs with 2 titles, but not considered Blue: NC State, Cincy, OK State, and San Francisco.
The “Honorable Mention” list is at least 1 title and 4 final fours: Michigan, Arkansas, Cuse, Georgetown, Arizona, UNLV, Ohio State, and Wisconsin.
It’s all up for debate, of course.