What Are The Odds: 1-2-3-1-2-3-1-2-3-1-2-3

For the seconds straight year we've seen an incredibly chalky quirk in the tournament. Last year it was all four #1 seeds reaching the Final Four, which I figured had about a 4.8% chance of happening given the top seeds' opponents (that takes into account things like Kansas' draw completely falling apart).

This year we've seen the chalkiest first weekend ever, with the average remaining seed being a ridiculous 3.06. A 12 and a 5 managed to sneak in there, but the top three lines all made it through unscathed. What were the odds of that?

In the table below are the money line odds for the top 12 teams in each of their first two games; using those, I derived their chances of making it out of the first weekend.

So it was 24 independent events, which had anywhere between a 98.1% (Carolina beating Radford) and 53.4% (Syracuse beating Arizona St.) chance of happening. Each higher seed was favored to win each game, but the odds of the faves winning all 24 were incredibly slim; 0.7%, or about 1 in 140. To put that in perspective, there was a better chance of ETSU reaching the Sweet 16 (0.9%) than nobody on the top three lines getting knocked out.

Sadly, I don't think 500-1 odds were available on the latter event happening.