I consider Duke, UNC, KY, Kansas, and UCLA as blue bloods. UCLA built up a lot of equity in the 60s and 70s. Georgetown was nearly a blue blood but couldn't keep up their status. UConn needs another natty or 2 to join the club. Indiana was there and kind of dropped out. After the 5 blue bloods the next group includes Indiana, Gonzaga, Arizona, Louisville, UConn, Memphis, Florida, NC State, and a handful of Big 10s and maybe another B12 or two. Ohio State, Michigan, Michigan State, and maybe Purdue since they have a winning record versus all others in the B10 teams iirc. There's a log jam after the top 8 or so. Also the time frame matters since Gonzaga is a new blood and Indiana had it rolling 30-40 years ago. San Francisco was once a power as well. Florida's success doesn't go back very far.