Which College Teams are Over-Ranked in Pre-Season Polls?

As we near Thanksgiving, I like to look back on the college football pre-season rankings.  It always makes for good comedy.  One thing (maybe the only thing?) I admire about the BCS is that they wait until the teams have actually played some games to attempt to rank them.  Pre-season rankings tend to be based on a mix of historical success, recruiting strength, and public perception.  Here is where we stand as of week 13:

              2012 AP Poll
  PreSeason                 Week 13

1 USC 1 Notre Dame

2  Alabama   2 Alabama

3  LSU   3  Georgia

4  Oklahoma   4  Ohio State

5  Oregon   5  Oregon

6  Georgia   6  Florida

7  Florida State  7  Kansas State

8  Michigan   8  LSU

9  South Carolina  9  Texas A&M

10 Arkansas  10 Florida State

11  West Virginia  11  Stanford

12  Wisconsin  12  Clemson

13  Michigan State  13  South Carolina

14  Clemson   14  Oklahoma

15  Texas   15  UCLA

16  Virginia Tech  16  Oregon State

17  Nebraska  17  Nebraska

18  Ohio State  18  Texas

19  Oklahoma State  19  Louisville

20  TCU   20  Michigan

21  Stanford  21  Rutgers

22  Kansas State  22  Oklahoma State

23  Florida   23  Kent State

24  Boise State  24  Northern Illinois

25  Louisville  25  Mississippi State

Saturday brought a ton of action, as KSU and Oregon both fell from the ranks of the undefeated.  Now, for the first time this season, the #1 rank goes to a team that wasn't even mentioned in the preseason rankings (Notre Dame).  After a long stint at #1, Alabama has regained its preseason position (#2).  Many of the rest of the preseason darlings have fallen from grace - particularly USC (1st to unranked), Michigan (8th to 20th), and Arkansas (10th to unranked).

What I find interesting is that often times you see the same teams year after year with high preseason rankings.  Usually, it is the teams with a long winning history: Oklahoma, Notre Dame, Alabama, USC, Texas, etc.  

To see what this looks like over time, I pulled all the pre- and post-season AP rankings from 1980 through 2011.  Then I looked at how over- or under-ranked each team was for that season.  For instance, LSU was ranked #3 in this year's preseason poll, and now they sit at #8.  That would count as being over-ranked by 5 spots.  Before anyone accuses me of insulting their team - I am not using "over-ranked" to mean "over-rated," and I'm not accusing any team of being bad or good.  The main point is to show the bias in pre-season rankings.

Click here for a larger version that is easier to read.

The graph includes teams that have appeared on an AP pre/postseason poll at least 5 times, and each point on the plot is one season.  By taking the mean of these values, the red bars show teams that are historically over-ranked, and the green bars are for under-ranked teams.  The outer (light) bar is the standard deviation, and the inner (dark) bar is the 95% confidence interval of the mean.

What you may notice is that the top over-ranked teams are some of the most successful programs of all time - Notre Dame, Southern Cal, Oklahoma, Texas, Nebraska, Michigan, Ohio State, and many others.  Most of the national championships in recent memory have been won by the teams at the top of the list. And this, I think, reveals the bias in pre-season rankings.  In August, no one has any idea who will be the best team in college football when January rolls around.  So the voters tend to choose teams that have been good before, and this leads to a persistent bias in favor of bigger programs.

At this point, you may be saying, "Who cares? Everyone knows that pre-season polls are terrible."  The problem is that pre-season polls are terrible, but they aren't meaningless.  A team's ranking drives the narrative behind their game that weekend, and influences their ranking next week.  If a team loses, they move down; win, and they stay the same.  It becomes very difficult for a team to leap-frog a team that started the season higher than them.  Look at the rankings last week: Notre Dame, KSU, and Oregon were all undefeated, yet their relative AP rankings perfectly followed their preseason.

              2012 AP Poll
  PreSeason                 Week 12

5 Oregon 1 Oregon 

22 Kansas State 2 Kansas State 

Unr Notre Dame 3 Notre Dame 

In 2004, USC and Oklahoma started the season #1 and #2, while Auburn was #17.  Even though all three teams finished the season undefeated, Auburn could never crack the top 2, and got shut out of the national championship game.

Tomorrow, the #2 team in the BCS rankings will probably be Alabama, putting them in the driver's seat to play Notre Dame in the championship game.  Behind them will be 10 other one-loss teams arguing their case, and they probably won't be successful.

Anyone else excited for college football playoffs in 2014?