Comparative Quarterback Pass Distributions
Posted by Derek
Much of the commentary regarding the future shape of the Eagles' passing attack has focused on presumed playcalling changes in response to the accuracy advantage Kevin Kolb should offer in the short and medium passing zones over the departed Donovan McNabb.
To my mind, Brian provided the definitive statistical breakdown of what we might call the Kolb effect in this post back in May. Plenty of other folks have made the same points with far less statistical support.
Brian used PFF data for his analysis, which was great, because it was more than we had from any other source back in May. However, Football Outsiders finally released their 2009 game charting data this week, which means we no longer have to content ourselves with summary-level data provided by PFF. With these Excel sheets, we can be as happy as a pig in slop drill all the way down to the individual play level, and with far more information than is retrievable from the official play-by-play logs.
Quick commercial interlude: If you're a true Birds number geek, you should really consider getting these data, especially now that they've created the convenient divisional bundles that will give you four years of data for the price of one. Check out the sample sheet before you make your decision, though, to determine if you're willing to put in the time to deciper everything in there. They're not exactly user-friendly.
Using the game charting data, I've broken down the Eagles passing attacks under McNabb in 2009, Kolb in 2009, and Garcia in 2006, since he seems to be the archetype for everything people are expecting from Kolb this year. The mega chart is below in PDF form, since it's too big for the usual image posting.
A few words of commentary first:
- It's impossible for us to completely separate play-calling from playing style. If Marty's worried about the rush and calls nothing but short and intermediate routes, the quarterbacks are going to end up throwing a lot of short and intermediate passes.
- With that said, quarterback style matters a lot. Tony Romo and Drew Brees aren't just different in the sense that one is better than the other. They're also different in terms of how they play, and defenses need to adjust accordingly.
- Each one of those differences has a good side and a bad side. Brett Favre takes a lot of stupid chances. Brett Favre also makes a lot of amazing plays. Closer to home, Donovan McNabb regularly holds on to the ball too long in the pocket. McNabb also gives his guys plenty of time to get open, and will come off to his second, third and fourth reads looking for the receiver in the best position to make a play.
- Kolb isn't just more accurate than McNabb. He's also less experienced, has a weaker arm, trusts himself more to put balls into tight spaces, and looks to be far more prone to feed the ball to his initial read, the way it's diagrammed in the playbook.
- As this season advances, we'll see those things play themselves out. I'm not saying Kolb won't be good. Please, fanboys, hear me on this. I'm not knocking Kolb before we get a chance to see him on the field. What I am saying is that there will be differences in how the offense looks, and it won't just be because every perfectly-thrown 10-yard completion leads to a 40-yard gain.
So how different did the passing offense look last year under Kolb? Very.
The usual small sample size caveats apply, even more so because we're looking at a new player's first two starts and the coaches weren't totally sure how he would react. But the differences are still pretty striking.
Numbers that jump out immediately:
- Fully one-third of Kolb's pass attempts went to the right side at a distance of between 1 to 10 yards. Neither McNabb nor Garcia was anywhere close to that number. To me, this suggests a player who was coached to hit the first read if it was there and did exactly that.
- Less than 20 percent of Kolb's passes went over the middle. That's a more dangerous place on the field, with a lot more bodies moving around at a lot of different angles. Not sure the coaches wanted him poking that hornets nest too many times.
- The red boxes speak for themselves. Again, though, sample sizes. And who wants to bet me that the first pass play of the Eagles season is double streaks and a 40-yard throw, just to show everyone, "Yeah, we can still do that."
- The behind-the-LoS pass numbers are also somewhat interesting. I stripped out all the screens and shovel passes, because I only wanted to look at plays where the quarterback had to make a decision about where to go with the ball. I'm intrigued by Kolb's relatively low dumpoff percentage (9.0% vs. 11.4% vs. 15.5%) and how that might benefit us if it holds up this year.
Of course, the biggest takeaway is that Kolb needs to prove this year that he can threaten the whole field in order to back defenses off and not have it be open season on his speedy wide receivers.
Now about his offensive line ...