2011 Pressure Plays, Defense
by Danny Tuccitto
With training camps about to start, the 2012 season is just around the corner, so it's time to finish up our series of posts detailing noteworthy charting stats from 2011. This week's topic: pass pressure. We'll start with defenses, and look at quarterbacks in a few days. These and all the other stats we've discussed this offseason appear in the statistical appendix of Football Outsiders Almanac 2012, which is on sale both in print and as a PDF file.
In previous years, we made a weird error: When we talked about how teams did with pass pressure, we only looked at hurries, not scrambles. That's kind of silly, isn't it? So this year, we made sure that we marked every play as either "pressure" or "no pressure." All sacks were marked as "pressure" plays except those marked either "Coverage Sack" or "QB Fault." (QB Fault sacks are when a quarterback slips on the grass or drops the ball on his own.) We also marked a play with pressure if it was either a quarterback scramble or a pass attempt where we listed a defender with pass pressure, or we listed "overall pressure." Finally, keep in mind that the stats in the table below include yardage and DVOA from defensive pass interference penalties.
|Rk||with Pass Pressure||without Pass Pressure||Difference|
|Rk||with Pass Pressure||without Pass Pressure||Difference|
We've sorted the table by pressure percentage, so let's start the discussion there.
For the second year in a row, no defense pressured opposing quarterbacks as frequently as the Texans did. The fact that Houston repeated despite missing Mario Williams for most of the season is a testament to Wade Phillips and their pass-rushing depth: Four front-seven defenders not named Mario had at least 20 hurries and five hits on opposing quarterbacks. That, along with drafting Whitney Mercilus, should soften the blow of Williams' departure to Buffalo, where coincidentally the Bills also repeated their ranking from 2010.
Just below Buffalo is Green Bay in dead last, which might seem surprising until you remember -- it's been a while -- that the Packers defense also ranked dead last in Adjusted Sack Rate. What separated them from the Bills, however, was that the Packers better maximized their efficiency on the relatively rare pass plays in which they did get pressure. Perhaps that's one factor that explains how the 24th-ranked pass defense can go 15-1 in this day and age.
Speaking of just winning, NFL Network reran the episode of A Football Life featuring Al Davis yesterday, and showed a clip of him mentioning how his main emphasis on defense, as early as 1963, was putting pressure on the pocket. Presumably, coaching in the pass-happy AFL had something to do with it, but no doubt he was simply inferring its success from past experience. I bring this up not to name Davis as a pioneer of pressure, nor to lure Raiderjoe into the comment thread (OK, maybe there's a little of that), but simply to point out the following. If league-wide DVOA averages in the table are any indication, advanced statistics about today's NFL lend numerical support to what Davis (and others) opined 50 years ago: pocket pressure is paramount.
Of course, it's not just that the average defense was more efficient with pressure in 2011; every defense has been so for the two years we've been keeping track. Now, at this point you might be thinking, "Well, duh. Sacks are hugely positive plays for a defense, so of course a defense's DVOA with pressure is going to be awesome when sacks are included." And you'd be right. However, this phenomenon persists even if we remove sacks, intentional grounding calls (which are essentially sacks), and scrambles from the equation so as to focus solely on hurried throws. In that case, Cincinnati had the lone defense that was actually better without pressure last year (+1.4% DVOA difference), while only Jacksonville (+24.5%) and Seattle (+13.8%) bucked the trend in 2010. That's still 61 out of 64 possible teams that benefited from pressure having nothing to do with the yardage lost on sacks.
Almost all defenses are better with pass pressure than without, but the size and nature of the difference varies wildly from team to team. A handful in 2011 were like the '85 Bears (or '91 Eagles) when they got pressure, but like the '09 Lions when they didn't (e.g., Washington). This group included both Super Bowl participants, one of which was missing its best pass rusher in early February. The other happened to have their three Pro-Bowl pass rushers as healthy as they had been all season. And no, I was not contractually obligated to point that out.
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Trolling aside, the member of that boom-or-bust group with the most misleading split is Minnesota. That's because the Vikings' stellar DVOA with pressure was almost entirely due to sacks, which were almost entirely due to Jared Allen. Focusing again only on throws with pressure, their DVOA inflates by 147.9 percentage points, and their ranking drops all the way from fourth to dead last. Those kinds of numbers make it almost masochistic to think about how spectacularly awful Minnesota's 32nd-ranked pass defense would have been if not for Allen narrowly missing out on Michael Strahan's NFL sack record.
On the other end of the spectrum were several defenses that got a smaller efficiency premium from pass pressure than other defenses did in 2011 (e.g., Atlanta). In this group, the Jets, 49ers, and Dolphins stand out as being the inverse of the Vikings. All three have bottom-tier DVOAs with pressure when we include sacks, intentional grounding calls, and scrambles, but ascend up the rankings when we focus only on thrown balls (e.g., Miami jumps all the way from 29th to sixth). What this trio had in common was a rusher who amassed a hurry total wildly disproportionate to his sack total. Calvin Pace had 20 hurries but only 4.5 sacks, Justin Smith had 28 hurries but only 7.5 sacks, and Cameron Wake had 39 hurries but only 8.5 sacks. On the other hand, Jared Allen actually had more sacks than hurries (21.5).
That's all for now. Stay tuned for Part 2 later this week, where stats will agree with another long-standing, pressure-related bit of NFL intuition. No Al Davis, though.
34 comments, Last at 26 Jul 2012, 6:53pm
#1 by mansteel (not verified) // Jul 24, 2012 - 2:13pm
I'd actually rather see the table that doesn't include sacks and grounding data--that gives us a better idea of how pressure affects each team's secondary.
Also, it would be fun to each QB's DVOA with and without pressure (Kolb is my guess for biggest discrepancy).
Also, it would be interesting to see these numbers per # of rushers. We all know that, all other things being equal, pressure is good. But is pressure bringing five (or more) rushers more effective than no pressure rushing three?
And while I'm at it, why don't you bring me some lunch, too :)
#3 by Danny Tuccitto // Jul 24, 2012 - 2:53pm
That QB-specific request is actually the focus of part 2. You're welcome.
#7 by Karl Cuba // Jul 24, 2012 - 3:46pm
I'll take some sort of chicken wrap and a sprite thanks.
#4 by jimbohead // Jul 24, 2012 - 2:54pm
QB DVOA with/out pressure is in FOA's statistical appendix (p 560). Kolb has the 5th largest discrepancy, and is also the 5th most pressured qb. That said, they eyeball test tells me that he's below average without pressure anyways.
#2 by CoachDave // Jul 24, 2012 - 2:50pm
I'll take "Reasons Why the Colts Fired Bill Polian" for $500 Alex.
#5 by theslothook // Jul 24, 2012 - 3:06pm
Firstly, I love what FO has done because if there were one stat i wish to god the nfl actually charted, it would be pressure. TO me, pressure is a better stat than ints, sacks, or whatever as most of us have to take raw sack numbers and pretend like they are indicators of commensurate pressure.
One issue or question i have is, is pressure talied the same way by the charters? by that i mean, consider two scenarios. Example A: the qb hikes the ball under center but the de end immediately beats the lt and rushes at the qb before he hits his back drop, forcing him to scramble and throw it away.
Example B: Same scenario but the o line holds up fine, the qb scans the field finds no one, about 2.5-3s later the line finally gets there and then the qb scrambles and throws it away.
Does the defense get credited with a pressure in both cases?
#25 by Aaron Schatz // Jul 25, 2012 - 10:25am
We certainly try to have charters all mark things the same. We work on the definitions so people will understand.
I would say that with your examples, in Example A of course yes, there is pressure. In Example B, it depends on the time. 2.5 seconds isn't enough to consider something a "coverage scramble" or "coverage sack," but 3.5 or 4.0 seconds is. There is a line at a certain point where you stop considering something to be pressure.
Also, a few people last year would mark both "coverage scramble" and a defender -- in other words, the scramble was caused by a quarterback looking for a receiver, but the throw away was caused by a defender finally tracking him down. We do mark that as pressure.
#6 by Karl Cuba // Jul 24, 2012 - 3:44pm
The table looks odd to me, none of the top ten teams in percentage of pressure are ranked in the top half of DVOA with pressure. Seems strange.
Actually, Dallas at no. 10 are 14th in the DVOA with pressure ranking but the Jets at 11 are 31st so I still claim weirdness, or at least the lack of an intuitive correlation.
#8 by cstoos // Jul 24, 2012 - 3:55pm
There is an intuitive correlation. When facing teams that tend to pressure the QB more often, offenses plan for it. They expect the pressure and call plays in which the QB can get rid of the ball quickly if necessary.
When facing teams that hardly ever get pressure, well, they plan for that too. Longer routes. Deeper drops.
#9 by Thomas_beardown // Jul 24, 2012 - 4:19pm
Alternatively, teams invite some pressure to create more mismatches in the secondary when facing these teams.
In fact I wouldn't expect anything other than an inverse relationship between how often a team gets pressure and how good a defense it is when it gets pressure. Other than Mike Martz what OC would let a team that excels when it gets pressure, pressure his QB with frequency?
#14 by akn // Jul 24, 2012 - 7:32pm
I'm wondering if every screen play counts as a pressure play.
#10 by Joseph // Jul 24, 2012 - 5:00pm
Maybe I'm perceiving this wrong, but it seems from this chart, to have a great defense, get pressure on the QB as much as possible. I mean, the worst D while pressuring the QB (ATL) would be the 2nd or 3rd best D EVER in the DVOA era.
Me thinks that Bill Polian was on to something by keeping Freeney and Mathis as his DE's, and 1991 PHI's & 1991 NO's defenses rank as all time greats (in the DVOA era) because of killer pass rushes (White & Jerome Brown? for PHI, and OLB's Jackson & Swilling for NO).
#11 by Thomas_beardown // Jul 24, 2012 - 5:12pm
I think you have it right.
The thing to worry about is when you blitz and don't get there. Remember that the "no pressure" table includes blitzes that get picked up.
#12 by Danny Tuccitto // Jul 24, 2012 - 5:43pm
Pressure pct. isn't related to DVOA w/ pressure in any meaningful way. So, yeah, the table does scream out that, on average, it's waaaay better to get pressure than to not get pressure. However, it doesn't say that getting pressure more often is better than getting pressure less often. Or, to put it another way, it's not how much, but what you do with it.
#13 by BroncosGuyAgain // Jul 24, 2012 - 7:13pm
1. This is further evidence that the sack is the most over-emphasized stat in football. Yes, a sack is a very significant negative play, but it is relatively rare. Hurries are also highly significant (although not as much as a sack), but largely ignored in the popular discussion.
2. The data are derived independent of scheme. It would be easy to look at this and say "obviously, we should blitz more often". But game planning is an exercise in trade-offs. More pass rushers means fewer pass defenders; that successful pass-rushing defenses outperform does not suggest that sacrificing pass-defending is "worth it". The data does not measure the trade-off. It only suggests that those teams good at pass-rushing (however achieved) tend to outperform.
3. OK, a scramble is the same as a pressure. But what is a charter to do when Tim Tebow begins scrambling with nary a defender within a body's length because, that is what Tim does? Codification is a good and necessary endeavor, and it will always be unable to capture the broadest range of human expression.
Finally, good analysis FO. This is the sort of data worth looking at, and I thank you for bringing it out.
#15 by MJK // Jul 24, 2012 - 7:41pm
I wouldn't necessarily think this implies you should blitz more often. When you blitz, you leave a receiver uncovered. If the QB can identify that receiver (his "hot read", he will throw long before the blitz gets close to him, and it will look like "no pressure". Similarly if the blitz gets picked up, as you imply.
#24 by Aaron Schatz // Jul 25, 2012 - 10:22am
If Tebow starts scrambling with absolutely no pressure whatsoever, it will be marked by the charter as "coverage scramble" and then it won't be counted as pressure.
So I'm sure Tebow and Vick and guys like that end up with more pressures because of scrambling, but not as many more as you might think.
#16 by theslothook // Jul 24, 2012 - 10:11pm
I think this list is yet another screaming indicator for the value of good coverage. The table seems to say fairly definitively that pressure affects pass production(intuitively correct), but its not a panacea. In essence, good pass defense seems to be derived from good coverage which both affects how good your team does against no pressure and with pressure, while the reverse is less so true(at least from the table).
I wonder how much the whole, "rush the qb and good things happen" mantra is lazy analysis vs incomplete footage of the back 7. I imagine now that we have all 22 access, this might eventually change as we can finally be able to tell exactly how the back 7 are playing certain receivers and route combinations, even able to tell what schematic disguises and different coverage wrinkles were being utilized instead of all that being swept under the rug.
The next big project to come of this imo will be which positional groupings most effect pass defense and against which types of passing offenses. We all know linebackers, safeties and corners are all part of coverage but great passing defenses don't necessarily need good players at every level, maybe just 2 out of the 3 units. In time we'll know if it is indeed better to have good corners vs safeties vs linebackers; i hope anyway.
#17 by Saintsrolltoth… (not verified) // Jul 24, 2012 - 11:11pm
Thanks for the analysis.
I would like to see a breakdown of the
sacks and pressures by down. Third down, the sacks are far more critical
than a first down pressure or sack and the team goes on
to make a first down. Also by quarter.
A sack in the 1st quarter can be overcome, some teams start slower
than others and the first few games of a season are usually
not quite a real spectrum of what goes on throughout the season.
Last year with all the turmoil and shortened training for rookies
also skews the stats a bit.
#18 by Jim Z. (not verified) // Jul 24, 2012 - 11:21pm
After correlating the teams with the best 2011 pass defense DVOA (BAL,NYJ,PIT,DET,JAC,SF) to their corresponding entries in this chart, I've come to the conclusion that the key to fielding a top passing defense in the NFL is being able to minimize the impact of pass plays when your defense is either slow to generate or unable to generate pressure on the QB.
- Two of the top six teams in pressure % generated finished #23 (OAK) and #31 (TB) in passing defense DVOA. The Rams, another one of those six, finished #14. Each of these three teams did extremely poorly when their defense did not pressure the QB (#20, #27 and #30). So despite generating a high rate of pressure, these teams' secondaries completely folded when the defense did not generate pressure.
- The top six teams in passing defense DVOA in 2011 (BAL, NYJ, PIT, DET, JAC, SF) have the following rankings in the "DVOA without pressure" section of the above chart: #2, #1, #6, #4, #7, #10. Their overall pressure % generated frequency ranking varies a bit more, however: #2, #11, #9, #14, #24, #3.
So it appears that while generating a high rate of pressure is important - and most of the top passing defenses do so - being able to maintain defensive composure when pressure is *not* generated is even more important.
#19 by Jim Z. (not verified) // Jul 24, 2012 - 11:36pm
Because the very nature of pressure dictates that its presence cannot be assumed in more than 4 out of 10 snaps, at most. The best team last year at pressuring the QB (Houston) only did so at 33% rate.
So for the bulk (at least 65-70%) of its snaps, a defense has to deal with an unmolested QB making his reads and progressions. It figures, therefore, that the ability to deal with an opposing offense when pressure cannot be relied upon is the key to successful NFL defense.
Any defense can be successful when pressure is generated, as shown by this chart. What they do when pressure is not available separates the top defenses from the mediocre defenses.
#20 by Aaron Brooks G… // Jul 25, 2012 - 12:18am
My gast is flabbered that the Lions had the 4th best non-pressure pass defense. My concept of reality does not allow for such an occurence. I can only posit that I am living in an artificial dream world, or the Lions headquarters has been taken over by pod people with advanced zone coverage skills.
#21 by theslothook // Jul 25, 2012 - 1:22am
its possible that the lions flameouts were just more publicized than their overall seasonal body of work. Both packer games really stand out in addition to that game against the saints.
Still... i have to agree that my impression of the lions was a defense highly dependent on pressure, but that could be because the myth and storyline have been ingrained that its hard to break free(or maybe i just keep taking that stupid blue pill).
ON the other hand, it could just be that for better part of a decade, the one constant for every one of those lions teams has been an abysmal secondary that its hard to break from that reality.
#27 by chemical burn // Jul 25, 2012 - 12:30pm
It's also possible that their pressure caused QB's to get jumpy even when it didn't make it to them - that they rushed throws out of fear. That's one way in which a reputation can help a team or a unit. I know with the 1991 Eagles, opposing QB's would panic before anything even happened to them (because it was very likely to happen in that case and be just brutal when it did come.) I think there's something reasonable (if easy to overstate) to the idea that opposing QB's and o-lines can get rattled.
#22 by peterplaysbass // Jul 25, 2012 - 7:21am
"Those kinds of numbers make it almost masochistic to think about how spectacularly awful Minnesota's 32nd-ranked pass defense would have been if not for Allen narrowly missing out on Michael Strahan's NFL sack record."
Alternately, imagine how many sacks Allen may have gotten if QBs under pressure didn't have such a porous opposing secondary to bail them out. Poor Allen.
#26 by Will Allen // Jul 25, 2012 - 11:49am
I think the game the Vikings secondary had, against the Tebow led Broncos offense last season, may have been the worst game any secondary has had since the '78 rule changes, especially once one considers that it occured on a home field which greatly favors pass defense, given good to excellent pass rushers.
#29 by jmaron // Jul 25, 2012 - 1:19pm
I've watched every Vikings game since 1998 and that was without a doubt the worst secondary play in any single game by a Viking team since that time....and that is really saying something because they have had some God awful defensive back play in that time period.
In games that actually mattered in that period...2000 NFC Championship against the Giants and 2001 vs the Rams...
Other than Winfield - have the Vikings had an above average db in the last 15 years?
#30 by Thomas_beardown // Jul 25, 2012 - 1:23pm
Darren Sharper was still pretty good when the Vikings got him.
#31 by Will Allen // Jul 25, 2012 - 4:16pm
At least that Giants game and Rams game were on the road, against an above average NFL qb who played more than 15 years, and a borderline HOF qb in a MVP type season. In contrast, the disaster last season came at home, against a qb who may not throw better than half the qbs in the MAC. It was truly stunning to watch, and I was looking for a report the next day that the Vikings secondary was seen doing jello shots at a local strip joint at 5 AM on game day.
#32 by GMan (not verified) // Jul 25, 2012 - 7:53pm
You are wrong. Tebow's will to win, character, and integrity caused the defense to play bad. You obviously don't get football and don't get why Tebow is great.
On a more serious note, this is the first Tebow game I watched, and if someone told me a rumor that Tebow paid the Vikings secondary to lay down for him, I would believe it without any further evidence. There were multiple plays where the DBs literally just let the WRs run past them.
I knew it was going to happen as I watched the game, but I loved how the narrative afterwards was this is the game where Tebow proved he can throw the ball. The game had the exact opposite affect on me. It solidified my complete skepticism on Tebow because against a secondary that bad, an even semi-competent QB should pass for more than 200 yards. I also liked how Tebow was credited with leading his team to a game winning drive when said drive begin at the Vikings 15 yard line.
#23 by slipknottin // Jul 25, 2012 - 9:00am
Giants are interesting. 3rd in the league in sacks, but 25th in pressure. #2 ranked pass defense with pressure.
Shows they did not get pressure often, but when they did it almost always resulted in a sack.
#28 by FrontRunningPhinsFan // Jul 25, 2012 - 12:44pm
When I first saw Al Davis' name, my first thought was: Seems like everyone's been missing RJ lately, not just me.
When I first saw you saying it wasn't to lure him into commenting I thought: Liar.
Then you admitted it. Great article.
Fire Jeff Ireland.
#33 by Kyle Williams (not verified) // Jul 25, 2012 - 10:24pm
So I muff a few punts, and you still can't say it:
NEW YORK GIANTS, SUPERBOWL CHAMPIONS
Stats show both the 49ers and the Pats are clearly better, so can't we just be happy with that?
#34 by zenbitz // Jul 26, 2012 - 6:53pm
Without rigorous analysis - it's my suspicion that the difference in "Pressure" DVOA is just noise. What is really the difference between a -70% and -110%?
Pressure rate seems more critical is more critical (and as others have pointed out - non pressure DVOA), although you would want to see year-to-year correlations.
Another thing to look at... how does pressure DVOA change with down/distance. If my defense forces a lot of 3rd-longs (easier to get pressure) does that mean they will have a lower pressure DVOA? Because, essentialy, the degree of difficulty for the offense is harder?