I've talked on here before about the limitations of discrete ranking systems—that is, ones where teams are simply ordered as No. 1, No. 2, No. 3, and so on. Everyone intuitively knows that they can be deceiving, and we hear about it whether it's announcers saying things like, "there's a bigger gap between No. 4 and No. 5 than between No. 5 and No. 10" or AP voters complaining that there are about 15 teams they could put in the Nos. 21-25 spots on their ballots.
While thinking along these lines again recently, I got the idea of figuring out how many peers each SEC team will have in 2016. By that, I mean how big is the group of programs in which each team is roughly equal.
To this end, I used the early 2016 S&P+ projections. The standard disclaimer that goes here is that no one knows anything in the preseason—to say nothing of the fact that the final preseason S&P+ projections don't come until August—but they're good enough for an estimate.
We often will refer to S&P+ rankings around here, but the actual measure is termed in points. Alabama is the top team in the projections, and its S&P+ number is 26.8. What that number means is that the Tide would be expected to be about 26.8 points better than a purely average team. Ole Miss is at No. 7 with an S&P+ of 18.9, so it implies that Bama is about 7.9 points better than the Rebels. Obviously actual events have variance, so these are general expectations.
What counts as "equivalent teams" is entirely subjective, but the measure I used is being within a touchdown's worth of points. In the example above, Ole Miss is just outside of being a peer to Alabama. No. 2 LSU, with its S&P+ of 24.4, would be a peer of Alabama (and also of the Rebels, incidentally).
Enough setup. Here is how everything turned out:
|Team||S&P+ Rank||S&P+||Highest Peer||Lowest Peer||Total Peers|
|Alabama||1||26.8||-||No. 4 Oklahoma||3|
|LSU||2||24.4||No. 1 Alabama||No. 7 Ole Miss||6|
|Ole Miss||7||18.9||No. 1 Alabama||No. 25 Texas A&M||23|
|Tennessee||9||17.0||No. 4 Oklahoma||No. 30 Miami (FL)||25|
|Georgia||15||16.2||No. 4 Oklahoma||No. 34 Texas||30|
|Arkansas||17||15.2||No. 4 Oklahoma||No. 38 Iowa||33|
|Florida||19||14.5||No. 5 Florida State||No. 39 Utah||34|
|Mississippi State||21||13.6||No. 5 Florida State||No. 42 Minnesota||37|
|Auburn||24||12.5||No. 6 Michigan||No. 45 WKU||37|
|Texas A&M||25||12.5||No. 6 Michigan||No. 45 WKU||37|
|Missouri||47||5.1||No. 26 Nebraska||No. 80 Air Force||54|
|South Carolina||63||2.8||No. 31 TCU||No. 90 MTSU||59|
|Vanderbilt||69||1.8||No. 35 BYU||No. 95 Ohio||61|
|Kentucky||83||-2.4||No. 51 Duke||No. 105 Georgia State||54|
For the most part, this seems about right to me. I can see most of these teams hanging with whoever their highest peer is and getting a challenge from whoever their lowest peer is.
The one that sticks out the most is South Carolina, as I don't think the Gamecocks could give TCU a good game. Along those lines, Bill Connelly thinks his S&P+ numbers have the Frogs wrong and expects TCU to move up in the August projections. Those projections will include things that the early ones do not like players coming back from injury and transfers.
Anyway, it goes to show that there really is a big separation at the top followed by a ton of teams bunched up together. Vandy is projected to be within a touchdown of nearly half of all FBS teams, whereas only three other teams figure to be within a touchdown of Alabama if everything plays out as expected.
Looking at peer programs doesn't just illustrate the stratification of the distribution of teams. It can also serve as a way to analyze a schedule, and that is coming in the not-too-distant future.