Meaning that say a #15 seed knocking off a #2 seed in the first round would be a bigger upset than say a #8 over a #1 seed in the second round? Technically by the numbers that is true, but to be the biggest upset ever to me would mean that the top team or maybe one of the top 4 went down before the Elite 8, as happened to Baylor. And if Baylor had lost in the Elite 8 it might well still qualify for me as the biggest upset. The fact is, Stanford was not really a #1 seed in 1998 after losing its top two players just prior to the tourney, so the seeds in a sense do lie there. Nothing lies about Griner and Sims and company going down. They just lost in a big way, in the third round, as reigning champ, and as the big favorite.
When the Bears lost by 12 in 2011 to Texas A&M it was in the 4th round as is not included on the list above. The big surprise there was that the Bears had beaten the Aggies three times already, but we have since learned how tough it is to beat a team 4 times in a season. Not looking too far ahead, but hopefully that trend of the previous winner losing game 4 will continue if it by any chance crops up (cross fingers).
And maybe it was an earth shaker when #1 seed Iowa lost in the 1992 without winning a game, I just can't remember that now, and when BC knocked off OSU in 2006, I don't recall it being that huge a surprise.