Preseason polls are worth exactly what you pay for them

It’s college football season again, and I am excited about the possibilities. Week one brings an excellent out-of-conference matchup between Alabama and Michigan played at a neutral site in Dallas that, according to preseason polls, features two of the top ten teams in the country. But are Alabama and Michigan really in the top ten, or are they coasting on their considerable reputations?

Methodology

In evaluating whether teams are properly rated, the first thing that comes to mind is to simply compare preseason and postseason polls. The difference in rankings would show up as a positive (underrated) or negative (overrated) change from preseason to postseason. The weakness with this method is that it treats all spots as the same. A team rated 20^th going into the season that finishes 24^th would be a -4, just like a team that rated 1^st going into the season and finished 5^th. To me, the second miss should be more significant because the gap between the 1^st and 5^th best team in the country should be much larger than that between the 20^th and 24^th best teams (think of the far right of a bell curve vs. the area closer to the middle). Because of the system that adds weight to movements at the top it will be extremely hard for a team to show up as overrated without being in the top portion of the polls, but that seems like a reasonable proposition as a team starting in the high teens cannot be considered highly rated. Now we just have to think about the best way to systematically account for errors in different ranges of the poll.

In a previous post, I used the average postseason Sagarin points to account for the varying differences between teams from the top (larger gaps) to the bottom of the poll (smaller gaps). While using votes for each team is another option, it relies on the polls themselves – which we are examining for flaws – rather than a reasonably reliable third party. The Sagarin rankings are postseason but, in theory, that’s what the preseason rankings are striving for. Check out the demonstration of the dropoff in points from 1 through 25 displayed nearby (this will help provide context for the numbers in the tables below). Now that we have a methodology, let’s put it to work.

College Football History 102: Effects of Conference Realignment

This is the second in a series on college football history. Read the first one here.

Conference realignment has been one of the major stories in college football since December 2009, when the Big Ten publicly announced that it was considering expansion. I found the Frank the Tank blog relatively soon after and enjoyed keeping up with things through his perspective, which emphasized the College Presidents’ point of view rather than sports fans. The story seemed to pull in fans and many prominent writers have been overwhelmed by their readers’ interest in the issue.

I think that conference realignment is an interesting topic not just because of the regional groupings of schools, the money at stake or the effect on classic rivalries, but because it is a chance for fantasy sports to move up a level. No longer are fans just picking players, their favorite team’s conference is now picking (or defending) top teams to make or break future power conferences.

Not only do I want to look at who won or lost the most recent realignment, I want to look at the significantly less important question of who won or lost previous realignments!