a few last minute thoughts on filling out a perfect bracket

Yesterday, I was on Madison’s CBS affiliate WISC-TV to talk about March Madness and filling out a bracket.

I was also on NBC15 in Madison to talk about the probability of filling out a perfect bracket.

Here is one data point from 2015:

Out of more than 11.57 million brackets entered in ESPN’s Tournament Challenge, one bracket emerged from the round of 64 of the NCAA tournament with a perfect 32-0 record. This is the first time there was a perfect first round in ESPN’s Tournament Challenge since at least 2010 (we’re still trying to find out exactly the last time it happened, but it’s been a number of years).

A little research uncovers 1 perfect bracket after the first 32 games in 54.85 million brackets at ESPN.

Last year, 25,704 of 13 million brackets (0.2%) remained perfect after the first 16 games and none were perfect after the first 32 games. None of those correctly picked the next 16 games.

The probability of a perfect bracket depends on the upsets in any given year. We can see that by observing the number of brackets that correctly selected all Final Four teams:

• 1140 of 13 million brackets correctly picked all Final Four teams in 2016
• 182,709 of 11.57 million brackets correctly picked all Final Four teams in 2015. This year stands out because the Final four was composed of #1 Wisconsin, #1 Kentucky, #1 Duke and #7 Michigan State.
• 612 of 11 million brackets correctly picked all Final Four teams in 2014
• 47 of 8.15 million brackets correctly picked all Final Four teams in 2013
• 23,304 of 6.45 million brackets correctly picked all Final Four teams in 2012
• 2 of 5.9 million brackets correctly picked all Final Four teams in 2011

Of course, these brackets missed several games along the way so none are perfect, but from these data points we can see that it’s inherently more difficult to pick a correct bracket when there are more upsets in any give year or unlikely teams in the Final Four.