Preseason rankings. Irrelevant in professional sports, but weirdly important in college basketball. I have shown in the past that rankings released before a single game has been played overvalue previous year’s NCAA Tournament success, so they clearly aren’t perfect. The odd wrinkle is that they also are just as predictive as pre-tournament rankings in determining who will make the Final Four. Given that the First Round starts tomorrow, I decided to look more closely into just how important preseason rankings are by looking at whether teams that outperform their preseason expectations regress in the NCAA Tournament. To do this, I reviewed all of the teams since 2007 that were unranked in the preseason and were ranked in the polls just before the NCAA Tournament (i.e., teams that performed better than expected during the regular season). In order to gauge how a team should do in the Big Dance, I borrowed Neil Payne’s win expectation chart by seed listed in this very interesting article. I then tested whether the teams that fit my definition for outperforming expectations did better or worse relative to win expectations than the rest of the field.
Here are the results.
|# of Teams||Expected Wins||Actual Wins|
The tested group of over-performers did in fact do worse in the NCAA Tournament than everyone else, and the difference is statistically significant. It should also be noted that an examination of the converse group — preseason ranked teams finishing the regular season unranked — produced no difference between win expectation by seed and actual wins. For some frame of reference, there are seven teams this year that have gone from unranked in the preseason to ranked now. That group is listed below. Read the rest of this entry »