To explain the columns below, Median is a median point spread, and can be used to get a feel for how good a team is without overly weighting a blowout win or blowout loss. HS is Brian Burke’s Homemade Sagarin, as implemented in Maggie Xiong’s PDL::Stats. Pred is the predicted Pythagorean expectation. The exponent for this measure is fitted to the data set itself. SOS, SRS, and MOV are the simple ranking components. MOV is margin of victory, or point spread divided by games played. SOS is strength of schedule. SRS is the simple ranking.
At this juncture, Baltimore was upset by Jacksonville 12-7, and consequently, there are changes at the top of the various stats. New Orleans sits atop the HS rankings, while Baltimore still has edges in median point spread and Pythagorean expectation. But I suspect for many the statistical darling of the moment is San Francisco, with solid Pythagoreans, a good record, and the best simple ranking of them all.
October 25, 2011 at 11:41 am
Glad I found your blog. I’ve been dabbling in NFL ratings the last few days. Today I put up ridge-regressed ratings through yesterday:
http://thecity2.com/2011/10/25/ridge-regressed-nfl-ratings-through-week-7/
A regression of Sagarin’s rating on RR gives R^2=0.88, which seems pretty good. Anyway, thought you might be interested.
October 25, 2011 at 1:18 pm
I am. But if the best you can do is a copy of Sagarin’s methods, you’ll never achieve more than he has. I’m not terribly enchanted with MOV derived stats, because I think they’ve been exhaustively mined.
How can you make a better stat? How would you go about it? What measurement is most important, point spreads or wins?
A lot of the best improvements in football analytics over the last 5 years have come from logistic regressions of stats, looking for those factors that win games.
And I’ve yet to see an offensive stat that can reliably predict playoff wins.
But don’t stop, keep looking and thinking..
David.
October 25, 2011 at 11:43 am
Oh, and thanks for putting up the median stats. That’s specifically what brought me to your post.