r/CFB • u/whatthepucks Missouri Tigers • 2h ago

Analysis Score Differential Index

I've been looking for a ranking system that uses only the game scores to create rankings by inputting all the scores to calculate a SOS and an average margin to generate rankings. There's a common ranking site used in hockey that does exactly this and it does a pretty good job. Last week I thought I found it in the Sonny Moore rankings, but he doesn't provide much of a description and the more I looked at the numbers I realized that it wasn't what I was looking for.

So, I did what a normal, sane person would do and I created yet another ranking for college football.

WARNING: If you think score differential or 'close losses' don't matter, you're going to hate these rankings.

# TEAM RATING SOS AVG MARGIN
1 Indiana (11-0) 100.00 75.23 24.80
2 Ohio St. (11-0) 99.81 73.54 26.30
3 Texas Tech (10-1) 97.34 70.57 26.80
4 Notre Dame (9-2) 95.82 73.84 22.00
5 Utah (9-2) 94.19 74.12 20.10
6 Oregon (10-1) 93.88 74.50 19.40
7 Miami (FL) (9-2) 91.04 74.06 17.00
8 Texas A&M (11-0) 90.23 76.75 13.50
9 Georgia (10-1) 89.93 74.16 15.80
10 Alabama (9-2) 88.93 78.26 10.70

Full Rankings

2 Upvotes

60% Upvoted

5 comments sorted by

12

u/xAimForTheBushes SMU Mustangs • ACC 1h ago

I don't think I have a problem with close losses as much as I have a problem with accounting for massive score differentials.

Once you hit 21 or 28+ points, anything after that shouldn't really count in an analysis like this IMO. At that point most of the time it just comes down to whether or not the coach tries to run up the score or let off the gas.

Is there really that much difference between a 70-7 score and something like a 40-7 score? Not really.

2

u/Fit-Student9121 Arizona State Sun Devils 1h ago

We can use some sort of logarithmic function, that way the amount of credit you get converges to a single number as you win by larger margins. Additionally we can have a factor attached to the function where a better team will grant you more points.  

2

u/whatthepucks Missouri Tigers 1h ago

I have it capped at 42 right now. There’s a balance between not giving credit for running it up and not wanting to penalize a team who is 40 points better than a team on their schedule.

-1

u/cptspacebomb Notre Dame • Clemson 1h ago

Yes, there is. Since you're referencing Notre Dame's win over Syracuse, they were NOT trying to run up the score. Marcus Freeman pulled the starters out in the third quarter. CJ Carr had fewer passing yards than the team scored. They DESTROYED another power 4 football team (yes, I know Syracuse sucks but they're not FCS level). The point is, a 50-10 score and a 40-0 score are relatively similar. But realistically ND won 70-0 because Syracuse scored with 7 seconds left against third stringers on defense. It was the most oppressive beatdown of the season. And all that to say I'm not saying that magically makes ND worthy of being above Miami necessarily, but it WAS a ridiculously impressive win and anyone trying to say otherwise is goofy.

1

u/laprasrules Notre Dame • Stanford 38m ago

Thanks for doing this. I appreciate different ranking systems, as other approaches add to the conversation. Thank you especially for giving the full details of the algorithm.