Friday, August 5, 2011

Thoughts on ESPN's New Qb Rating QBR

The whole Chinese calendar thing never really made sense to me.  I think I was born in the year of the rooster, or maybe the year of the rat?  ESPN apparently has no love for it either, they've recently proclaimed 2011 as...


As far as ESPN promotional campaigns go, this one is relatively innocuous.  Whether it's the year of the quarterback for any kind of clear reason would be debatable, but at least it isn't the absolute travesty that was the absurd 'Who's More Now?' campaign.

Anyway, ESPN has opened the Year of the Quarterback (which was almost called the Year of Boring CBA Negotiations), with the debut of a new statistic, conceived to take the current QB rating and advance it.

They're calling it QBR, which somehow is short for Total Quarterback Rating.  I guess it's technically TQBR, or Total QBR.  I guess that part needs work.

But ESPN is trying to give us a better QB Rating, and it's hard to argue with their logic.  The current standard for QB Rating is a relatively straightforward formula, but no one remembers it offhand or can easily calculate it.  It also can yield a perfect score of 158.3, which doesn't have the same ring to it as a perfect 10, or even bowling a 300.

So they want to replace it.  Cool. 

From their description, it seems like ESPN is trying to keep pace in the stats arms race, the one that gave us the MIT Sloan Sports Conference, Moneyball, and dozens and dozens of eager young quant jocks trying to break into the business.

Again, makes sense to me.  Anything that gets more analysis into the public consciousness is fine.  Then maybe we'd get some more insights from our broadcast announcers.

But I wonder to what extent this new Total QBR is going to seep into the public.  Most specifically, I wonder about this because I can't seem to find any details on how the formula itself is even calculated.

It spits out a number for each QB between 0 and 100, that's a good idea.

And a review of it's results over the last three seasons pass the initial smell test.

Peyton Manning has the top two slots with his 2009 and 2008 seasons, the middle rankings have QBs like Matt Cassel and David Garrard, and Jamarcus Russell comes in dead last.

And I also get the logic behind including the win probability via expected points per play.  That's a reasonable approach to me, based on my understanding of what they've done.

But the inclusion of 'Dividing Credit' and a 'Clutch Index,' give me some pause.

In terms of 'Dividing Credit', this is what they say about the formula:

On a pass play, for instance, there are a few basic components:
• The pass protection
• The throw
• The catch
• The run after the catch

In the first segment, the blockers and the quarterback have responsibility for keeping the play alive, and the receivers have to get open for a QB to avoid a sack or having to throw the ball away. On the throw itself, a quarterback has to throw an accurate ball to the intended receiver. Certain receivers might run better or worse routes, so the ability of a QB to be on target also relates somewhat to the receivers. For the catch, it might be a very easy one where the QB laid it in right in stride and no defenders were there to distract the receiver. Or it could be that the QB threaded a needle and defenders absolutely hammered the receiver as he caught the ball, making it difficult to hold on. So even the catch is about both the receiver and the QB. Finally, the run after the catch depends on whether a QB hit the receiver in stride beyond the defense and on the ability of a receiver to be elusive. Whatever credit we give to the blockers, receivers and quarterback in these situations is designed to sum to the team expected points added.

The ESPN video tracking has been useful in helping to separate credit in plays like these. We track overthrows, underthrows, dropped passes, defended passes and yards after the catch. The big part was taking this information and analyzing how much of it was related to the QB, the receivers and the blockers. Not surprisingly, pass protection is related mostly to the QB and the offensive line, but yards after the catch is more about what the receiver does. Statistical analysis was able to show this, and we divided credit based on those things.

In an earlier post where I discussed why the NFL doesn't lend itself to statistical analysis as easily as baseball, I talked a lot about the difficulty of measuring intent and assigning value to different teammates coordinating the activity.

It's clear the ESPN stat gurus have also thought about this, and apparently have developed some solution.

But they don't describe how exactly they did it, which has me quite curious, because it seems like that would be by far the greatest challenge in building this metric.  Who's responsible for the success of the pass?  And how would you even start to divvy that up amongst the players?  Because if you could do that accurately, you'd be in a whole new world in terms of attributing the reasons for victory, which would have dramatic implications for players and their earnings potential (by this I mean, if we could suddenly say the right guard drove a significant proportion of his team's offensive success, and could somehow measure that with objective data, suddenly that guard might argue he should get paid more than the right tackle)

I'm pretty confident the guys at ESPN haven't gotten that far deep into details, but without knowing it just has me wondering how they got to where they are.  Maybe they're talking about it in their TV debut tonight, but I would assume not.

That brings me to the larger question of how broadly this will be adopted.

If you want a metric to become the standard for everybody, it sure as heck helps if you tell us all how to calculate it.  Even if we can't do the math ourselves, showing it removes the black box 'trust us' element from the equation.

They can integrate it into Monday Night Football all they want, but until I see a little more under the curtain (or skirt for a more adult analogy), I'm withholding judgement.

Even if I agree with it about Manning and Russell.

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