Sunday, March 11, 2012

Bracket Advice #2: Lucky vs Overrated

One of the most controversial things that I hammer home here is the concept of "luck". It's controversial for readers, at least. It's not really controversial in the statistical community. It's simply a reality that once a game is decided by five or six points or less then luck plays a large role. Clutch play exists, but it's a small factor. Even the most un-clutch team in the country is still going to win very close to 50% of their close games.

Results in close games have been studied repeatedly in basketball, football and baseball, and all have found that results in future close games are not in any way correlated to results in previous close games. Teams that win a bunch of close games in a row are like people flipping a coin and getting a bunch of heads in a row - your next flip is still 50/50. You're welcome to read this post that I wrote on this topic during the peak of Tebow-mania.

There's a myth that great teams "just find a way to win", but that's garbage. What great teams do is they blow out opponents so that luck can't play a role.

As a rule of thumb, you want to bet on teams that have been unlucky this season. Teams are seeded by resume strength, and a team that's been unlucky has played better than their seed, and therefore is a better team than their seed would indicate.

An easy way to see which teams have been lucky or unlucky is to look at their Sagarin ratings. The Sagarin ELO_CHESS is a measure of resume strength while the Sagarin PREDICTOR is a measure of team strength. A team with a better PREDICTOR than ELO_CHESS was unlucky, and vice versa.

This year I wanted a second, more objective measure of luck, so I decided to just rank all 68 teams by Pomeroy Luck factor. The Pomeroy Luck rating is a measure of the difference between team quality and resume quality. The team ranked #1 was the luckiest team in the country. Avoid them.

The full list is below (click on the image to zoom in):


Obviously we've known all season that St. Louis and Memphis are way underrated. Stat-heads have been screaming for those teams all season long. I (kind of) believe that the Selection Committee forcing those two teams to play against each other in the Round of 64 was their way to stick it to the young bloggers sitting in their pajamas, to do the thing that would piss them off most. I feel the same way every time baseball gives a Gold Glove to Derek Jeter.

Obviously Texas is another team much better than their resume. Ken Pomeroy calls them the most underrated team in the country, and I agree. Ohio State is another team that has been unlucky in conference play. Keep in mind that these numbers are only through Saturday's games, so the impact of the Big Ten title game is not felt in these numbers.

1 comment:

Anonymous said...

are you going to put up your bracket?