Common sense. You demand some mathematical criteria for who is and who is not a blue blood, as if you'll only accept the results based on some fucking algorithm. You're falsely framing the argument from the outset, and it's horseshit. What's the criteria? It's fucking common sense and a general knowledge of the sport.
Texas, Notre Dame, Ohio State, Alabama, Oklahoma, Nebraska, USC, Michigan.
If Nebraska disappears for another fucking 15 years, maybe they fall the way of the dodo like Minnesota. Honestly, that'll probably happen. Georgia wins at the rate they're winning, maybe in 15 more years they can take that spot. There's a reason Miami isn't on that list, a 10 year elite level run of elite-ness and 20 damn good years, and five national titles didn't get it done, but people here stanning Georgia. Georgia has had a great decade. Hell, LSU has a pretty good run for 20 years, they're not on the list either.
Most of us recognize a blowjob when we see and feel it, but you'd sit around arguing if it qualifies as one because of the ratio of mouth versus hand technique before zipping up your pants in frustration and scratching your head as you pondered what you were actually receiving.