Writers of Pro Football Prospectus 2008

30 Sep 2011

Under Pressure: The Meaning of Mobility

by J.J. Cooper

Do scrambling quarterbacks lose more yardage on their sacks then less mobile quarterbacks? The answer appears to be no.

In fact, the opposite appears to be true. In response to Eddo’s comment on the first Under Pressure, here’s a look at the average yards lost per sack from 2009-to-present for every quarterback with 20 or more sacks.

Yards Lost per Sack, 2009-Week 3, 2011
Quarterback Sacks Yards Lost Yards Lost per Sack Quarterback Sacks Yards Lost Yards Lost per Sack Quarterback Sacks Yards Lost Yards Lost per Sack
Jake Delhomme 29 229 7.89 Jimmy Clausen 33 222 6.72 David Garrard 75 469 6.25
Carson Palmer 52 405 7.78 Derek Anderson 36 240 6.66 Matt Cassel 68 423 6.22
Matt Stafford 33 249 7.54 Bruce Gradkowski 22 146 6.63 Matt Schaub 63 391 6.20
Kurt Warner 24 178 7.41 Jason Campbell 78 517 6.62 Mark Sanchez 62 383 6.17
Kerry Collins 24 177 7.37 Matt Hasselbeck 65 428 6.58 Ryan Fitzpatrick 46 280 6.08
Eli Manning 56 404 7.21 Shaun Hill 35 229 6.54 Alex Smith 58 348 6.00
Drew Brees 51 367 7.19 Jay Cutler 101 658 6.51 Tom Brady 44 264 6.00
Sam Bradford 45 321 7.13 Joe Flacco 83 538 6.48 Michael Vick 38 228 6.00
Donovan McNabb 80 569 7.11 Peyton Manning 26 167 6.42 JaMarcus Russell 33 198 6.00
Ben Roethlisberger 91 641 7.04 Josh Freeman 52 333 6.40 Colt McCoy 26 152 5.84
Matt Moore 22 153 6.95 Chad Henne 67 422 6.29 Philip Rivers 69 399 5.78
Trent Edwards 34 234 6.88 Kyle Orton 71 447 6.29 Tony Romo 47 263 5.59
Brett Favre 56 384 6.85 Aaron Rodgers 87 546 6.27 Jon Kitna 21 114 5.42
Kevin Kolb 26 176 6.76 Matt Ryan 55 344 6.25 Vince Young 22 118 5.36

What’s notable is that the the quarterbacks with the lowest yards per sack include many of the most agile quarterbacks in the league. Michael Vick, Vince Young,and Colt McCoy are all known for their agility.

At the other end of the spectrum, Carson Palmer, Kurt Warner and Kerry Collins all rank among the top 10 of most yards lost per sack. Apparently, slow feet bring longer sacks as part of the package. One of the best ways to explain it is that mobile quarterbacks often try to run when they are pressured -— sometimes that results in sacks at the line of scrimmage or just behind the line of scrimmage. Less mobile quarterbacks are less likely to try to run for positive yardage.

It’s also notable that the spread between the quarterbacks with the shortest average sack and the longest average sack is over three yards per sack.

Along those lines, it's worth looking at whether the time of a sack makes a difference in the yards lost. Looking at every sack since 2009, the answer is yes.

Yards Lost per Sack by Time Elapsed, 2009-Week 3, 2011
Time of Sack (Seconds) Average Yards Lost
0 to 1.5 5.87
1.6 to 2.0 7.52
2.1 to 2.5 7.27
2.6 to 3 6.92
3.1 to 3.5 6.21
3.6 to 4 5.41
4.1 and up 4.49

It's not surprising that extremely quick sacks result in less lost yardage -- most sacks that take place in 1.5 seconds or less come on three- and five-step drops or when the quarterback just falls down. But it's notable that the most yards lost comes when a quarterback is sacked in 1.6 to 2.5 seconds. Once we enter into the land of long-duration sacks, the yardage lost goes down the longer the quarterback holds the ball.

Anecdotally, after watching every sack since 2009, the best explanation I can come up with is that many of the longest sacks are on bootlegs where a quarterback runs out of bounds or is caught at the sideline close to the line of scrimmage. For some of the other long sacks, they come when a quarterback tries to scramble after being pressured, which again leads to shorter distance sacks.

Since we're talking about yards lost, it's worth noting that the longest sack in yardage lost this week was a 13-yard loss by Tavaris Jackson when Cardinals outside linebacker Joey Porter drove tackle Russell Okung back into Jackson.

GET RID OF THE BALL

It wasn’t the longest sack of the week, but it’s hard to find a more crucial one than Rex Grossman’s 4.1-second sack and fumble that clinched the Cowboys’ victory. Anthony Spencer did run Grossman down and force the sack, but it was DeMarcus Ware that actually causing the sack.

The Cowboys sent three, and right tackle Jammal Brown, who had been terrorized by DeMarcus Ware for most of the night, did a decent job blocking Anthony Spencer. Spencer showed a speed rush, and Brown routed him well past Grossman to the outside, although in doing so, he did lose contact with Spencer once Spencer had gotten past him.

But on the other side of the line, Ware used a speed move to split the double-team of Trent Williams and Kory Lichtensteiger. Although he didn’t get the sack, that pressure forced Grossman to roll out of the pocket.

Patriots coach Bill Belichick has described behind the quarterback as the worst place a pass rusher can be, but in this case, it was a great place to be. As Grossman rolled out, Spencer ran him down from behind and ripped out the football. The Cowboys recovered and the game was over.

Ware’s pressure came only 2.3 seconds after the snap, not enough time to really find someone open when there are eight men in coverage. Grossman did have time to get rid of the ball before Spencer ran him down, but he never saw Spencer coming from behind him.

CAUSE FOR CONCERN

The Lions are 3-0, which means that it’s hard to find any Lions fan complaining about anything these days -- if you’ve survived Matt Millen and 0-16, then 3-0 is a level of bliss you’ve never dreamed of seeing in person.

But in the Lions’ win over the Vikings on Sunday, there was a cause for concern when it came to pass protection. Detroit's tackles Gosder Cherilus and Jeff Backus simply couldn't handle the speed of Jared Allen and Brian Robison.

Allen picked up three sacks and Robison added two more. Forget about the number of sacks allowed for a second -- the time of the sacks should be disconcerting for the Lions. All five of those sacks came in 2.5 seconds or less. Cherlius and Backus were barely slowing Allen and Robison down.

LONGEST SACK OF THE WEEK

Before Vick left the game with a bruised hand, he was pulled down by Jason Pierre-Paul in one of the more impressive sacks of the week. At the snap, Pierre-Paul beat Jason Peters off the line, then also dodged the block of running back LeSean McCoy. By doing that, he managed to flush Vick out of the pocket. Vick still had time to get rid of the ball, but eventually Pierre-Paul ran Vick down from behind, 6.1 seconds after the snap.

Many times a great individual effort like Pierre-Paul's will end up ensuring someone else gets a sack. But in this case, the man who deserved the sack got the credit for it as well.

QUICKEST SACK OF THE WEEK:

The quickest sacks of the week are usually based on blown assignments or a tripping quarterback. This week, Bears guard Chris Williams seemed to fall into the first category.

Against the Packers, Williams blocked down, helping out the center. There was one problem: Jarius Wynn was lined up head up on him. No one else picked up Wynn, so he got the easiest sack he'll get all year, pulling down Jay Cutler only 1.7 seconds after the snap.

Posted by: J.J. Cooper on 30 Sep 2011

19 comments, Last at 03 Oct 2011, 9:59am by RichC

Comments

1
by Aaron Brooks Go... :: Fri, 09/30/2011 - 1:59pm

How many of those 1.6-2 second sacks at 7.5 yards occur to shotgun QBs? That long yardage sack list seems to include a lot of shotgunners, whether they scramble (Brees, McNabb) or not (Palmer, Warner, Collins).

2
by J.J. Cooper :: Fri, 09/30/2011 - 3:03pm

Just taking a quick glance at this year. 10 of the 19 sacks this season of 1.6 to 2.0 seconds have come when the quarterback lined up in shotgun. On those shotgun sacks, the average yards lost is 7.8 yards. It's 8.9 yards on average on non-shotgun snaps in the same timeframe. Granted that's a much smaller sample size, but it doesn't seem to indicate that the shotgun plays a large part in yardage lost. Overall, QBs taking the snap out of the shotgun are averaging 6.8 yards lost per sack this year. On non-shotgun snaps, they are averaging 6.3 yards lost per sack.

7
by CaffeineMan :: Fri, 09/30/2011 - 3:36pm

This is an interesting question. It's always seemed to me that for pocket QB's, the longest sacks occur when an N step drop becomes an N+M step drop. The QB thinks that with just one more step backwards, they can get the pass off and they end up adding another M steps to the sack yardage before the sacker catches up. They'd actually be better off just eating the ball after the initial N steps if there's not enough time to throw it away.

Scrambling QB's don't seem to do this, they either throw it or start scrambling and actually have a chance to get away from the pursuit. Good pocket QB's don't seem to do it either. Any movement is sideways or up and they either get rid of the ball or eat it with minimal yardage loss. I have nothing to back this up, just my impression.

8
by Aaron Brooks Go... :: Fri, 09/30/2011 - 4:24pm

"It's not surprising that extremely quick sacks result in less lost yardage -- most sacks that take place in 1.5 seconds or less come on three- and five-step drops or when the quarterback just falls down. But it's notable that the most yards lost comes when a quarterback is sacked in 1.6 to 2.5 seconds."
----------

It's been commented that a freely-released defender will perform a sack right about the time a 5-step drop finishes, in the neighborhood of 1.5 seconds. (The quick sack)

My point was that for a shotgun QB, a quick sack will take somewhat longer, because the QB is further from the line. Shotgun QBs are nearly immune to the 1.5s sack as a matter of geometry, however, they suffer quick sacks in the 2-2.5 second window, whereas a drop-back passer has had time to step forward into the pocket for sacks in that time window.

Granted, you occasionally have given the Aaron Brookses of the world time to heave a fumble backwards 40 yards or so.

3
by zlionsfan :: Fri, 09/30/2011 - 3:06pm

meh. 3-0 is nice, but those of us in our 40s (or older) have seen 4-0; even Lions fans ten years younger have seen those "play-off" things to which other fans allude. (Trust me, 38-6 is something I'll remember my entire life.)

I haven't charted Vikings-Lions yet, but something to remember is not that we should be concerned about Backus and either Cherilus or Hilliard, but that we should already know their limitations. Backus has held down the left tackle spot for every game in his Detroit career, and while he's been serviceable, his physical peak has passed; Cherilus may have the potential to be a solid RT, but hasn't really shown it yet. Stafford had to get rid of the ball quickly on a number of plays in the first couple of games, and it's likely he'll have to keep that in mind the rest of the season ... Linehan will probably continue to use two-TE sets and keep Best and Morris in for pass protection from time to time as well.

9
by Aaron Brooks Go... :: Fri, 09/30/2011 - 4:25pm

Barry Sanders spraining a DB's ankle without touching him is something I'll always remember.

4
by Alexander :: Fri, 09/30/2011 - 3:06pm

Jay "The Sackmaster" Cutler deserves his own statistical analysis. From my experience he has learned to get sacked in every way possible: Sacked on the snap, sacked while still dropping back, sacked while scrambling, sacked from holding the ball too long, sacked during pregame warmups...

5
by hansen9j :: Fri, 09/30/2011 - 3:15pm
6
by J.J. Cooper :: Fri, 09/30/2011 - 3:16pm

That's my theory too...As mentioned in the story.
"One of the best ways to explain it is that mobile quarterbacks often try to run when they are pressured -— sometimes that results in sacks at the line of scrimmage or just behind the line of scrimmage. Less mobile quarterbacks are less likely to try to run for positive yardage."

10
by LionInAZ (not verified) :: Fri, 09/30/2011 - 7:12pm

I think this analysis runs roughshod over the data. Tom Brady is not considered particularly mobile, yet is on the low end. Donovan McNabb is supposedly mobile, yet loses yards with the worst. "Mobile" QBs such as Rodgers, Cutler, and Freeman are in the middle of the pack. Are Jon Kitna and Matt Cassel scramblers?

The author just cherry-picked QBs out of the bunch to prove a point.

11
by Mr Shush :: Fri, 09/30/2011 - 8:50pm

He would have done better to leave McCoy out of this; Vick and Young really do belong in a different category to every other player on the list. There are mobile quarterbacks, and there are QB/RB tweeners. It's a pretty major distinction.

17
by Aaron Brooks Go... :: Sun, 10/02/2011 - 5:44pm

Kitna is a scrambler.

18
by RichC (not verified) :: Mon, 10/03/2011 - 9:57am

If you don't think Brady is mobile, you haven't watched him play.

He's not very fast, but there's no one who avoids pressure quite as well as he does. There's a huge difference in watching him "sit" in the pocket vs watching someone like Carson Palmer.

Sometimes a step sideways and a step forwards is more effective than trying to outrun the defender to the sideline.

12
by nat :: Fri, 09/30/2011 - 9:30pm

Yards per sack isn't that interesting in the end. You've got the wrong denominator in your ratio. Yards per sack doesn't tell us whether QBs are good at avoiding deep sacks or just "good" at not getting back to the line when they scramble.

We already have sacks per dropback. Actually, we have even better: adjusted sack rate. But you could have given us sack yardage per dropback. That would have been sweet. We could have looked at whether those mobile QBs are actually gaining or losing yards by scrambling rather than throwing the ball away. (To be even better, you would also consider positive scrambles in a separate combined ratio: non-throwing yards per dropback.)

13
by KK Probs (not verified) :: Fri, 09/30/2011 - 10:40pm

This is definitely worth measuring. Limiting the damage on a busted play is a skill set that a QB must have, and to some extent his entire offense must have it with him. The sack yardage averages above don't look terribly significant with a difference of 2.53 yards over the entire sample (consistently falling forwards when being sacked can account for most of 2.53 yards). But I suspect that these QBs would have larger differences if we sorted out short sacks, like under 2.5ish seconds where the QB doesn't have a chance, from long sacks, where scrambling skill comes into play.

In fact, it would be interesting to take it one step further and see what the results are for QBs on passing plays that go different lengths of time, whether they end in a sack or not. For instance, what is a QB's DVOA on all pass plays that don't end in a sack within the first 2.5 seconds. We could then not only measure instances where the QB got sacked, but what his overall ability was in busted plays, beyond just avoiding sacks. Brett Favre was a very good scrambler when it came to avoiding the pass rush on busted plays, but he always stayed behind the line of scrimmage and looked for receivers to get open, especially later in his career; he rarely ran the ball forward. I suspect Tom Brady possesses the same skill.

This brings up a number of strategic possibilities. When you're Payton Manning, you should probably throw the ball away when you're in trouble. But when you're Michael Vick, you should probably try to make something happen - which will result in more sacks, but less damage on the whole if some of those become big runs, and some of the sacks at least end up a couple of yards closer to the line of scrimmage than they would have for other QBs.

Where I really see this disparity in optimal QB strategies (besides for Young and Vick) is in college football, but let's not get too scattered.

This whole notion of adding analysis of time to specific plays is adding an extra dimension to football analysis that, as far as I can see, has never really been done before in the media. The interpretations are raw for everyone because the data is new, but this type of data is gold. It's sort of like a 40-yard dash time or counting bench press reps, but it's actual real football results. Good stuff, keep it coming.

16
by J.J. Cooper :: Sat, 10/01/2011 - 9:55pm

Thanks K.K.

19
by RichC (not verified) :: Mon, 10/03/2011 - 9:59am

"This is definitely worth measuring. Limiting the damage on a busted play is a skill set that a QB must have, and to some extent his entire offense must have it with him."

But it doesn't measure that. If a QB gets hit in the backfield, and manages to get back to the LOS, its no longer measured as a sack. IE, if he succeds in eliminating the damage, you're removing the result.

You could have a QB who is the best ever at turning a broken play into positive yardage, and he may still show up poorly in this metric.

14
by Jake (not verified) :: Sat, 10/01/2011 - 1:05pm

to me the sack thing sounds like play action passes where someone comes free from the blind side. the quarterback sees him just in time to panic into trying to run, as CaffeineMan said, and the linebacker ends up riding him down an extra few yards.

15
by Karl Cuba :: Sat, 10/01/2011 - 1:07pm

Good stuff but a graph of some kind would have been helpful for the "Yards Lost per Sack by Time Elapsed, 2009-Week 3, 2011" chart.