Why is the 5-12 upset so common in the NCAA Tournament?

I'm not a bracket junkie, but one theory might be that the 5-12 and 4-13 match ups are where the highly-motivated little conference teams end up against the slumping-down-the-stretch big conference teams.

my shoot-from-the-hip take on it. I believe this is because 12 is usually about where the last of the "at large" berth teams land (13-16 is where all of the auto bids for either teensy conference champions or those rare sub-.500 teams in larger conferences that win their conf. tourney). What you get in the last at large teams is often a say, 28-4 team from a mid-major conference that got upset in the first round of its conference tournament. Those teams are often better than the NCAA committee is willing to understand. Or to summarize: 12 seeds are more often, compared to 10 or 13 seeds, great teams from non-major conferences, and the NCAA committee is heavily biased to the big boys.

With no data to back me up, I'll say that I don't think 6-11 upsets are any less common than the 5-12. The 5-12 gets more hype because a 12 is usually a small conference team and a 5 a big conference team. This isn't always the case; I think recently Butler was a 5 matched up against a big conference 12 (illinois?) . I always think it's lame to put a big conference team in a 12 seed, because like it's way exciting when teams like western KY, Gonzaga (back in the day), Bucknell or Utah State beat a big name school. 13-4 is even more exciting, for the exact same reason, but it probably doesn't happen as much because the higher seed is usually stronger and the lower seed is weaker than in a 5-12 matchup.

oof, on proofread, where it says "because like" in my comment above, just pretend it only, like, says "because."

Do you have any stats to show that 12 beats 5 more often than 11 beats 6 or 10 beats 7?

I agree halfway with mcstayinskool. I don't really think that mid-major conference teams are too underrated but he points out that a great many of the 13-16 seed teams are automatic bid conference champions from weaker conferences that would never get an at-large bid. A lot of these teams might not really be in the top 64 in terms of talent. It's usually about the same number of these teams each year and they start to run out around the 12-13 seed. So it's more that the 12 seeds are significantly better than the 13-16 teams and the tournament starts to get more competitive at that point.

http://sports.yahoo.com/fantasy/nba/news?slug=be-tourney_primer_2010 I've definitely heard the 0-100 thing for 16 seeds other places this year. 11 is 31-69, 12 is 34-66, 13 is 21-79, 14 is 15-85, 15 is 4-96, and 16 is 0-100 Looking at those numbers, 3% better than the 11 seed isn't really that much (3 wins over 25 years). Maybe it's just luck combined with not-very-good minor conference champions taking up most of the 13-16 slots.

to provide some support for the argument a 12 seed is usually around where team quality starts to flatten out here is a http://www.basketballprospectus.com/article.php?articleid=993 from Basketball Prospectus they just put up today. Graph at the top make this point.

to provide some support for the argument a 12 seed is usually around where team quality starts to flatten out here is a post from Basketball Prospectus they just put up today. Dammit, I knew I should have checked Basketball Prospectus. That graph also indicates that 5 seeds are worse than 6 seeds, which might also be part of what's going on. I can see it being the case that, much like 12s are the last of the good teams, the 5 slot is where the committee stops being able to distinguish the relative qualities of the teams quite so easily, so they just throw in the 3rd best ACC team because they're familiar and have a good reputation.