Decided to dust off the ol’ blog for the new College Football Playoff system. I’m simply going to apply my Achievement S-Curve [see here] to college football to see who should be selected for the inaugural CFB Playoff this year.
Quick summary of what the Achievement Rankings are doing: determine the most deserving teams based on on-field accomplishments. From each team’s perspective all that matters is whether they won or lost, and how difficult the game was (opponent strength, home/away, etc.). For opponent strength, however, we are free to use a more predictive rating, or true strength. Simple example: the Arizona Cardinals at 8-1 against a tough schedule would come out on top of a most deserving ranking in the NFL and if they season ended today, they certainly deserve the #1 seed. However, the Broncos or Packers or maybe even Seahawks may be the best team and would come out on top of a predictive system (say, Inpredictable‘s, which has DEN #1, GB #2, NE #3, SEA #4…and ARZ #14).
There are two choices to make to utilize my system: you need a rating system to determine the difficulty of the game (mostly the strength of each opponent, but also home-field advantage, etc.) and you need to choose a baseline team to compare against. I’m going to use Sagarin‘s Predictor rating to determine opponent strength and for now, I’ll use the equivalent of the #10 team in the country as our baseline team since we are trying to determine the top 4 teams. So for each team I’ll find what record we’d expect the #10 team in the nation (think Ohio State or Oklahoma) to have had they played their schedule, and we’ll use Sagarin to determine that.
Let’s take Florida State as an example. Here’s their schedule with how often both the #10 team and the #25 team would be expected to win each game:
| Loc | Opponent | #10 Team | #25 Team |
| N- | Oklahoma St | 98% | 83% |
| vs | Citadel | 100% | 100% |
| vs | Clemson | 73% | 58% |
| @ | NC State | 94% | 79% |
| vs | Wake Forest | 100% | 100% |
| @ | Syracuse | 93% | 77% |
| vs | Notre Dame | 73% | 58% |
| @ | Louisville | 58% | 43% |
| vs | Virginia | 98% | 82% |
| @ | Miami FL | 60% | 45% |
On average, we’d expect the #10 team to win about 8.5 games against this schedule, and the #25 team would win 7.25 on average. Since Florida State is 10-0, their score is +1.5 or +2.75, depending on the baseline team you choose.
Achievement Rankings
Here are the rankings with a #10 team as the baseline:
| Rk | Team | ExpW | ExpL | W | L | Score | Score/G |
| 1 | Alabama | 6.49 | 3.51 | 9 | 1 | 2.51 | 0.251 |
| 2 | Mississippi St | 7.43 | 2.57 | 9 | 1 | 1.57 | 0.157 |
| 3 | Florida St | 8.46 | 1.54 | 10 | 0 | 1.54 | 0.154 |
| 4 | Oregon | 7.71 | 2.29 | 9 | 1 | 1.29 | 0.129 |
| 5 | TCU | 7.93 | 2.07 | 9 | 1 | 1.07 | 0.107 |
| 6 | Baylor | 7.14 | 1.86 | 8 | 1 | 0.86 | 0.095 |
| 7 | Auburn | 6.19 | 3.81 | 7 | 3 | 0.81 | 0.081 |
| 8 | Mississippi | 7.30 | 2.70 | 8 | 2 | 0.70 | 0.070 |
| 9 | Georgia | 7.32 | 2.68 | 8 | 2 | 0.68 | 0.068 |
| 10 | UCLA | 7.45 | 2.55 | 8 | 2 | 0.55 | 0.055 |
| 11 | Ohio St | 8.57 | 1.43 | 9 | 1 | 0.43 | 0.043 |
| 12 | Arizona St | 7.91 | 2.09 | 8 | 2 | 0.09 | 0.009 |
And if we lower the baseline to the #25 team, we get:
| Rk | Team | ExpW | ExpL | W | L | Score | Score/G |
| 1 | Alabama | 5.28 | 4.72 | 9 | 1 | 3.72 | 0.372 |
| 2 | Florida St | 7.25 | 2.75 | 10 | 0 | 2.75 | 0.275 |
| 3 | Oregon | 6.49 | 3.51 | 9 | 1 | 2.51 | 0.251 |
| 4 | Mississippi St | 6.52 | 3.48 | 9 | 1 | 2.48 | 0.248 |
| 5 | Auburn | 4.82 | 5.18 | 7 | 3 | 2.18 | 0.218 |
| 6 | UCLA | 5.93 | 4.07 | 8 | 2 | 2.07 | 0.207 |
| 7 | TCU | 6.98 | 3.02 | 9 | 1 | 2.02 | 0.202 |
| 8 | Georgia | 6.11 | 3.89 | 8 | 2 | 1.89 | 0.189 |
| 9 | Baylor | 6.38 | 2.62 | 8 | 1 | 1.62 | 0.180 |
| 10 | Mississippi | 6.23 | 3.77 | 8 | 2 | 1.77 | 0.177 |
| 11 | Ohio St | 7.49 | 2.51 | 9 | 1 | 1.51 | 0.151 |
| 12 | Arizona St | 6.69 | 3.31 | 8 | 2 | 1.31 | 0.131 |
I prefer the higher baseline, which gives more credit to top wins and less to middle tier wins. In either system, the top 4 are Alabama, Florida State, Oregon and Mississippi State, albeit in different orders. TCU, Baylor, and Auburn are next in line in the #10 version. UCLA climbs up to #6 in the #25 version, as they have a bunch of middle-tier wins (Virginia, Memphis, Texas, Washington, etc.). It’s up to you what type of resume you want to reward.
A couple quick notes:
- College football teams play so few “connecting” games (i.e. non-conference games) that team strength ratings (like Sagarin) are very sensitive to these and conferences as a whole can move up or down the ratings based on just a handful of out of conference matchups. The SEC is certainly very strong this year, but it’s possible they as a conference are overrated due to this phenomenon.
- This system does not incorporate certain things that others may thing they should. Some of these I’m okay with: conference championships, for instance, or recent performance. Others, I am strongly against: head-to-head and especially the dreaded “eye” test.
In any case, I’m excited to see how the whole thing plays out. College Football finally has a Playoff.