Thursday, July 5, 2012

College Football History 101

Since it’s the middle of baseball season and the NBA draft just finished up, I decided to write about football. Actually, it was the announcement of a real playoff for college football that spurred me to take a look at the sport. Given the dominance of the SEC in the past several years – culminating in a title game that featured two SEC teams from the same division – I wanted to take a look back in history and see if any other conference had a similarly dominant run.

Because college football has never had an official championship we need to make some assumptions to be able to define dominance. I decided to go with the AP poll, since it has been around since 1936 and is one of the more-reputable ways for teams to claim national championships in the pre-BCS days.

Link between rank and points (linear and Sagarin)
Conference dominance, though, should look at more than just the number one team to see how an entire conference is performing. The polls can help with this too. By looking at the top 20 (top 25 since 1989) and assigning point values to each, we can give an overall value to the performance of all the top teams. While we miss out on valuing the lower-level teams, those teams are terrible and I don’t care about them.

Rather than just assigning points in a linear manner (i.e., 1st ranked team gets 25 points, 2nd ranked team gets 24 and so on), I wanted to dig a little deeper. I used the average Sagarin rankings for the past couple of years to determine what the curve looks like from 1 to 25. I took the value above the 26th-ranked team and gave that to each team rather than 25-24-23 etc. The Sagarin-influenced chart looks like this:

This should better-capture the difference between truly elite teams at the very top and the merely good teams at the lower end.

Contemporary Membership

In case you haven’t noticed, conference membership is in flux right now. We’ll need to look at this both ways, but we’ll start with membership as it was in any given season.

Conference Performance - 4 yr average 1936-2011 (Contemporary Membership)
This figure shows the trailing four year average for percentage of total ranking points (according to the Sagarin scale above) going to each conference. Four years seemed right for college athletes and smooths out some of the noise. The table lists the top performance for each conference and the year in which it took place.

Peak Performance (Contemporary Membership)
The SEC peaks in the last year of the data, and the two “conferences” above them are not really conferences. ‘Others’ peaks in the mid-1940s because several WWII-era training bases featured teams that were ranked at the time. ‘Independent,’ at the time of their 1990 peak, included Notre Dame, Penn State, Miami and a number of other schools in the eastern US, but was not an organized conference. All this is telling us that, based on contemporary membership, the SEC really is at the pinnacle of any conference since the AP poll started.

Top SEC Seasons (4 yrs ending)

Looking at the SEC’s own top seasons, however, we can see that this pinnacle is only slightly above their peak of the early 1960s. The current peak is slightly higher, but the level of dominance has been done before from the late 50s through the mid-60s.

Current Membership

The data look somewhat different if we turn back the clock and realign teams to their current (or near-future) positions. For this perspective each team is placed in the conference they are currently committed to. That means Pittsburgh and Syracuse are considered ACC teams, Missouri and Texas A&M are in the SEC and all those wonderful Nebraska seasons move over to the Big Ten, where they bring the peak forward a bit from 1943 as it is based on contemporary membership.

Conference Performance - 4 yr average 1936-2011 (Current Membership)
Peak Performance (Current Membership)

The peak for the SEC is now 1962 rather than 2011. The entire 1970 to 2000 range for the SEC averages 23%, not too far off the 29% they would have had for 2011 based on current membership.

Of interest to me is that the ACC has improved its position the most when current teams are included looking backwards. This may simply be the combination of two historically good runs (Miami and Florida State) that are now included in the ACC’s tally, or it may be an indication that the ACC is actually capable of challenging the SEC for best football conference.

Not quite there

Considering the data, it looks like the SEC is on one of the better runs of all time, but not necessarily the best. Particularly considering where the current group of teams would have had them in the past I am not prepared to call them the best ever.

They are, however, by far the best conference right now, nearly doubling-up the second placed Big 12 if contemporary membership is considered (28% to 17%) and still comfortably ahead if changes are included (A&M and Mizzou to the SEC, WVU and TCU to the Big 12) at 29% to 21%.

Next Steps

Because I really like this data set, and I spent a bit of time getting it ready, I am going to dig deeper and pull out some interesting visualizations of the data over time. In particular, I will look at conference performance geographically and also take a peek at team performance. It should be equivalent fun to a barrel full of monkeys whenever I get around to writing some more of these things.

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