Friday Figures: Blitzing Tony Romo (or Not)

Tony Romo Sacked Philadelphia Eagles Defense Sean Jones Trent Cole Juqua Parker

Just a quick stats post here for people to ruminate on over the weekend, before I hit you with some big news on Monday…

Today over at Iggles Blog, Derek has an insightful breakdown of the situational blitzing differences between the late Jim Johnson and rookie defensive coordinator Sean McDermott. His analysis led me to look back over the two sample game charts Football Outsiders released: the first halves of the two 2009 regular season Eagles-Cowboys games.

2009 Philadelphia Eagles Pass Rush Blitzers by DownFirst of all, let me just throw up the numbers for all of last year’s blitzing on the right. Overall, McDermott seems to have brought a few more blitzers on third down than JJ, but other than that the defensive playcalling was fairly consistent from 2008.

But were the game plans for the Cowboys games very different? Absolutely. In fact, the two were completely opposite. Here they are.

Eagles Blitzing against Dallas Cowboys Week 9 17 First Half by DownOn top you can see the differences in percentage from the season average for the first game. In this one the Eagles blitzed constantly, sending five, six, and seven guys after the quarterback way more than average. In fact, only on first down did McDermott blitz less than half the time.

Then a complete reversal for week seventeen. In every area where the defense had blitzed more than average in the first game, they did the opposite for the second meeting. Compared to 16 blitzes in the first half of week nine, come January the Eagles only blitzed four times! Perhaps the Eagles coaching staff thought that they had failed with the blitz in the first matchup, or they believed a coverage-based approach would surprise Dallas. Either way, the about-face is startling.

Eagles Blitz Effectiveness against Dallas Cowboys Week 9 17 First Half by DownOf course, we know that this change didn’t work too well. Which leads us to the final charts of the evening (at right), which shows the  effectiveness of the two game plans. I’m not sure that this can be extrapolated out for more than this particular case, but here the results suggest one thing.

Blitzing when the Cowboys didn’t expect it, i.e. on first and second down, was fairly successful. Outside of one long second down pass, the Eagles stifled Tony Romo with the blitz. But on third down, the roles were reversed. At least in these two halves, dropping players back into coverage was slightly more effective than blitzing.