I love it when he talks all statistic-y like that.

You readers know I’m a huge fan of Chris Brown’s Smart Football blog.  And you also know that “regression to the mean” is one of my big mantras for Georgia’s prospects this season.  So if Chris posts something on that subject, I’m gonna pay attention.

Linking to a WSJ piece, he references the following with regard to non-BCS bowl teams,

… The reason is a statistical principle called regression to the mean that is critical in sports, yet poorly understood. A player’s or team’s actual performance is an imperfect indicator of underlying ability. Luck — or statistical noise, if you prefer — also plays a role. Generally those who do well are better than average, but they’ve also probably had more luck than average. And the opposite is true of players or teams that do badly. SI . . . isn’t accounting for the underlying forces that are pushing these above-average teams — losing teams need not apply — back to average. After all, some of the teams that missed the bowl games this year are going to qualify next year…

and then adds this qualifier

I agree with this, but would only add that path dependence is likely a strong mitigant of mean regression when it comes to the biggest BCS teams, due to recruiting advantages and so on.

My first thought on reading that is well, dayum.  I don’t want to hear about strong mitigants after a season when Georgia finished minus-16 in turnover margin.  Then I clicked on his link to the definition of “path dependence” and got this:

Path dependence explains how the set of decisions one faces for any given circumstance is limited by the decisions one has made in the past, even though past circumstances may no longer be relevant.[1]

The phrase is regularly used to mean one of two things (Pierson 2004):

  • Some authors use path dependence to mean simply “history matters” – a broad concept;
  • Others use it to mean that institutions are self reinforcing – a narrow concept.

It is the narrow concept that has the most explanatory force and of which the discussions below are examples. The claim “history matters” is trivially true and reduces simply to “everything has causes”.

If I understand that correctly, Mark Richt’s decision to replace three members of his defensive staff ought to serve as a mitigant to the mitigant.  Particularly so, given the macro changes to the entire scheme, but also on the micro level in terms of changes in technique, like this:

… Rambo spoke excitedly about his off-season work and Georgia’s new defensive backs coach, Scott Lakatos.

“I take notes on everything he says, know[ing] it’ll help me out in the long run,” Rambo said. “It’s a whole lot different, especially with the footwork Coach Lakatos is teaching us. Most of the people in the NFL run the same thing Coach Lakatos is teaching us. . . . I’ll imagine myself making more plays this year.”

Am I reading too much into all of this and feeling more optimism than is justified?  What do you guys think?


Filed under Georgia Football, Stats Geek!

18 responses to “I love it when he talks all statistic-y like that.

  1. UFTimmy

    Isn’t Spring time the official time of optimism?


  2. This quote from Bobo in the AJC speaks to your point.
    “We’ve had change. We’ve had turnover. We struggled last year. Eight and five. But sometimes that’s good: You need to be on the fire. And I think it’s lit a fire in everybody.”
    Richt’s breaking away from the path dependance created by his reluctance in the past to make staff changes is significant.
    Both the staff and players sense the change. The atmosphere should b dramatically improved in 2010.
    Optimism warranted!


  3. Bulldog Bry

    The past two years, I’ve resided somewhere between a Gator-like arrogance of expecting to win it all and a Gamecock-like ‘this should be our year’.

    I know. It’s not healthy.


  4. The Realist

    You probably are reading too much into it, but nobody wants to begin the season with realistic expectations. That takes all the fun out of it.

    The turnover margin won’t repeat in 2010. It just can’t. Only changing that last year would have produced a 10-win season. So, it’s not too much to expect good things from this team considering the changes that have been made and the players that return.


  5. 69Dawg

    Last year was the perfect storm of turnovers. We were awful. The O giveth but the D didn’t taketh away. If that continues this year then we’re toast.


  6. Hogbody Spradlin

    Path dependence sounds like inertia. We were on path dependence through Auburn and WVU, 2005, UT 2007 and 2009, FL 2008 and 2009, Bama 2008, SC and ARK 2009, well you get the idea.


  7. 81Dog

    I’ll be glad to give you my opinion on this post as soon as I hire a consultant from the Economics Department and/or a professor with a doctorate in Statistics to explain all this to me in English.

    Regression to the mean? Macro changes? Path dependance? Fabulous!

    here’s my analysis for our defensive problems from last season, expressed in a formula:

    a/(bc) – (x) + 1 = W

    In other words, a represents the number of opposing team offensive plays, divided by b (the number of agile, hostile and mobile defenders we deploy) times c (the number of times said defenders knock the snot out of opposing ballcarriers and/or QBs) minus x (the number of times Bryan Evans, errrrr, a defensive back gets torched for an easy score) plus 1 (because based on historical analysis, we can almost always chalk up Tech as a win) equals W (the number of wins).

    Reduced to a simpler equation, if we knock the crap out of the other offense and quit giving up easy scores, we’ll win more. Now I know how that math whiz in A Beautiful Mind felt.


  8. Scorpio Jones, III

    I are a jounalism major, but I think 81Dog gets a big +

    Of course all this improvement is predicated on having some extremely loud music playing as we enter the stadium.


  9. Chuck

    If for you “realistic expectations” means “MNC, here we come”, then, no, you don’t have realistic expectations. On the other hand, if you mean “we are going to be significantly better and play to our potential”, I would say your expectations are realistic.

    Our basketball team is a good example. This is basically the same team as last years, but look completely different. They have 3-4 really solid players and a lot of youth. IMO, they play to their potential, but that hasn’t translated to a lot of wins. In fact, from a fan’s standpoint it is sometimes hard to watch because they seem to be soooo close to winning and then have it slip through their fingers.

    Back to football: I think we will be better, and will play much closer to our potential, but it is too early to start penciling in ‘Ws’.


  10. This whole “path dependence” thing totally bunks everything I learned at the Tull Accounting School regarding “sunk costs” (i.e. any costs that are going to be incurred no matter shouldn’t influence future decision making). More proof that the real world does not exist in the vacuum that academia likes to.


    • MT

      Path dependence and sunk costs are two different ideas.

      Sunk costs are, like you said, investments that have been made already and shouldn’t influence future decision making.

      Path dependence is saying that, because we have made a prior choice, our future options are limited because of that prior choice.

      For instance, if I have already bought a luxury box in Sanford for the 2010 season, at this point it’s a sunk cost. I shouldn’t evaluate my decision on going to the game based on what I’ve already purchased.

      However, my options for buying a luxury box for the Braves, Falcons, etc. have been limited somewhat, since I won’t have as much $ to committ.


  11. Mayor of Dawgtown

    I’m optimistic. I’ll go out on a limb and say we beat FLA and win the SEC East in ’10. I also like our chances a lot in ’11. Look at the UGA schedules, then look at FLA’s and UT’s schedules.


  12. thewhiteshark

    Statistical noise (or luck) should change (hopefully) with the new defensive staff in place. Georgia fans do have some reason to be optimistic. There is a lot of talent on this team. The difference between 8-4 and 10-2 or 10-2 and 12-0 is razor thin. Every turnover is a potential swing play in a game. The turnover margin against Florida the last two years has been 0-8. You would be hard pressed to beat a bad team turning the ball over 4 times while getting nothing back. Blogs and posts across the Bulldog world have covered Georgia’s defensive woes ad nauseum but, it does seem to me that you create your own statistical noise. Hopefully, under Coach Grantham, Georgia will do just that –something we haven’t seen much of in a long time.

    Find a quarterback and fix the defense and these Dawgs should be dangerous. But we shall see.


  13. As Usual, I agree with the Mayor Of Dawgtown. Maybe we are eternal optomists (or realists).


  14. Tommy

    When you read these pieces in the abstract, without any specific context to your team, you’re likely to find whatever you want to be there.

    I think turnover margin falls into the “we are what we do repeatedly” category. It’s not statistical noise (like, say, every opponent on your schedule getting an off-week before they play you), and it’s not something we should automatically assume will go away by trading a fifth-year senior QB for a redshirt freshman QB.

    Since we have nothing resembling empirical data going into 2010 (no spring practice, two-a-days or a home opener cupcake), the only reason I have to think turnover margin will get better is that, my God, how could it get much worse? -16 is a staggering number, and one you’d assume would at least be mitigated by Grantham’s attacking defense. That said, there’s a high beta with the first year of a move to a 3-4: we may get more turnovers, but we may give up more big plays.

    Our W/L ledger will get the most help from the weaker schedule. Are we better positioned in the make-or-break games (Tennessee, Florida, Auburn and Tech)? Hell, I have no idea.


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