FanPost

From the Fan Posts: Mythbusters: D-Line or Bust!

In examining the “D-Line or Bust!” philosophy, the most critical assumption it contains is the belief that the game of football is won and lost in the trenches.  The idea is that if you do not have a high-quality front line you are doomed.  Specifically, the argument this year is that you build a defense from the line up.  This has been worded in various ways, but the thrust of it is that picking a player like Patrick Peterson, even if he is a true once-in-a-generation player, will mean almost nothing if we cannot also consistently pressure the quarterback.  This approach has several factors to recommend it.   It has a sort of blue-collar mentality that meshes rather well with the game of football itself as well as the personality of many of its fans.  It has some prima facie evidence to support it -- all of the final four teams in this year’s playoffs have at least a respectable front line.  It also has the support of several incredibly bright and successful football minds.  Despite all this, I do not believe that the statistics support it.

What I hope to do in the discussion following is present a wide-ranging picture, using several statistical measures, of what a good passing defense looks like.  I will then attempt to separate out (as much as is possible) the effects of the secondary vs. the effects of the defensive line.  It will be of special interest to see if the adage "Show me a good secondary, and I'll show you a good D-line" is true.

There are at least two factors to consider when looking at the phrase “pressuring the QB”.  The most obvious (and most easily obtainable) is number of sacks.  The other is QB hurries.  We could also look at QB hits, or maybe even number of holding calls on the offensive line.  Unfortunately, neither hits nor hurries are official statistics compiled by the NFL, so we have to make do with what we can.  The best I could find was QB hurries through Week 14 of the 2010 season.  The following chart looks at all team sacks and adds to that number the amount of hurries generated by individual players (with at least one per game).  This result is called "Number of pressures", which is divided by total number of pass attempts for the year, to reach a percentage of passes that were attempted while under pressure.

Side by side with those standard statistics I also place the pass defense ranking of each team according to Football Outsiders' advanced statistics.  The name of each team on the chart will be coded one of three colors: red for bottom third of the NFL , yellow for middle third, and green for the top third.  In essence, a green team means a good secondary while a red team means a poor secondary.  Finally, I have ranked the chart by percent of passes pressured and separated it out by thirds, delineated by the black horizontal lines

 (EDIT: The horizontal lines didn't format out.  The top tier ends with Dallas and the middle tier ends with Baltimore)

# of pass attempts

# of pressures

% of passes pressured

team name

FO's pass ranking

547

87

16%

HOU

32

518

81.5

16%

DET

20

593

92

16%

PIT

2

502

68.5

14%

MIA

23

529

71.5

14%

MIN

19

570

77

14%

STL

21

470

63

13%

OAK

16

535

69.5

13%

IND

26

560

69

12%

ATL

10

527

62.5

12%

GB

1

540

64

12%

DAL

28

536

61.5

11%

PHI

11

526

57

11%

CAR

8

581

62

11%

KC

18

585

59

10%

SEA

29

550

53

10%

SF

24

488

47

10%

SD

4

582

54.5

9%

CHI

5

611

57

9%

NE

17

625

58

9%

TEN

12

507

47

9%

CLE

15

596

52

9%

BAL

6

539

46

9%

NYG

3

514

43

8%

CIN

14

578

47

8%

WAS

27

531

40

8%

NYJ

7

494

33

7%

NO

9

533

33

6%

ARI

22

473

27

6%

BUF

25

506

26

5%

JAC

30

521

26

5%

TB

13

502

23

5%

DEN

31

So if the D-Line argument holds any weight, we should find a strong correlation between the top pressuring defenses and the top passing defenses.  If it is difficult to read this chart, let me simplify it: there exists no such correlation.

First of all, the team with the highest percentage of QB pressures (i.e., Houston Texans) is also the worst-rated pass defense in the NFL.  This in and of itself, even as an outlier, would be problem for the D-line argument.  However, the problem persists: there are just as many bad pass defenses in the top tier of QB pressures as there are in the bottom tier (i.e., 4).  The same goes for good pass defenses: there are just as many in the top pressure tier as there are in the bottom pressure tier (i.e., 3).  In the top tier of QB pressures, there are only two top-5 passing defenses (i.e., Green Bay and Pittsburgh).  If I were to chart these statistics graphically, it would look like a random scatterplot with no line of symmetry.  Put simply, while it sounds reasonable to say that a good secondary is meaningless without a good front line, it is simply not supported by the evidence.

Need more proof?  The following are the top 5 passing defenses in the NFL, when measured by standard statistics.  They are grouped under the statistic in question; all ties are kept intact.  Since these measure events that occur primarily in the defensive backfield (i.e., yards, completions, TDs, INTs), they will be ideal for measuring which are the best secondaries in the NFL.

YPA COMP % TDS INTS QB RTG
Steelers Jets Saints Patriots Packers
Ravens Raiders Bears Packers Steelers
Chargers Chiefs Steelers Eagles Bears
Buccaneers Packers Packers Falcons Chargers
Packers Giants Chargers Bears Ravens
Chiefs Steelers  
Jets        

First of all, in case you are inclined to doubt the validity of Football Outsider's statistics or question whether a good passing defense for them is due more to the line than the secondary, I will note that the names which appear most frequently in the NFL's official statistics (i.e., Packers, Steelers, Chargers, Bears, Ravens, Jets, Chiefs) are all but one contained within the top third of Football Outsider's statistics -- in other words, they are almost all green teams.

The statistical dice roll continues in standard NFL stats.  Of those seven teams listed most frequently, two are in the top tier of pressure defenses (Packers and Steelers).  Four are in the middle tier (Chiefs, Chargers, Bears, Ravens); one is in the bottom tier (Jets).  Since 32 teams do not split into thirds evenly, it turns out that you could even count Baltimore in the bottom tier, further muddling the results.  In any case, there certainly does not exist the strong correlation you would expect if the D-line argument is true.

One quick note before I conclude: I will admit that these statistics are not comprehensive or perfect.  However, they are the best that is available, and they present a very clear picture that is unlikely to change with a bit more information.  If it seems unusual that a certain team is ranked low on the pressure scale, I would remind the reader that simply because a team attempts pressure (i.e., blitzes or brings four rushers) does not mean a team actually succeeds in creating pressure.  The actual number of sacks and hurries is far more reliable than the eye test or general media consensus.

What can be ascertained from all this?  I will concede one point: the most consistent teams are, interestingly enough, the two in the Super Bowl.  In order to win the Lombardi trophy, it does in fact seem as though a solid D-line is very important.  However, only four of the top tier of pressure teams (i.e., Packers, Colts, Falcons Packers) were playoff teams, lending no support to the claim that you have to have a high-pressure line to get into the playoffs.  In fact, there were two playoff teams (Jets and Saints) who had low pressure ratings.  There is little question that the amount of QB pressure brought by a team does not have the intrinsically necessary relationship to secondary success that is often claimed.

I'll disclose and state that I am on the Patrick Peterson at #2 bandwagon -- perhaps even driving it.  So I have an ulterior motive for compiling these statistics.  Without a doubt, our D-line is a major priority in the offseason and should be fixed as soon as possible.  However, it is not the earth-shattering all-or-nothing need that it is usually proclaimed to be.

This is a Fan-Created Comment on MileHighReport.com. The opinion here is not necessarily shared by the editorial staff of MHR

X
Log In Sign Up

forgot?
Log In Sign Up

Forgot password?

We'll email you a reset link.

If you signed up using a 3rd party account like Facebook or Twitter, please login with it instead.

Forgot password?

Try another email?

Almost done,

By becoming a registered user, you are also agreeing to our Terms and confirming that you have read our Privacy Policy.

Join Mile High Report

You must be a member of Mile High Report to participate.

We have our own Community Guidelines at Mile High Report. You should read them.

Join Mile High Report

You must be a member of Mile High Report to participate.

We have our own Community Guidelines at Mile High Report. You should read them.

Spinner.vc97ec6e

Authenticating

Great!

Choose an available username to complete sign up.

In order to provide our users with a better overall experience, we ask for more information from Facebook when using it to login so that we can learn more about our audience and provide you with the best possible experience. We do not store specific user data and the sharing of it is not required to login with Facebook.

tracking_pixel_9341_tracker