The two exceptions are Baltimore, which is second in the NFL in sacks, and Dallas, which is 26th in the NFL in sacks. Both of these teams average under 70%.
Pittsburgh, by the way, gets 65% of its sacks from non-blitzing personnel (23rd in the NFL) and is ranked 20th in the NFL in pass defense.
Furthermore, of those four top 10 passing defenses that are not among the NFL's top 10 sack leaders, three are among the top 10 in not letting up big plays (over 25 yards).
Pittsburgh is ranked 23rd in the NFL in big plays allowed.
Of the ten teams that get the highest percentage of their sacks from blitzing, all but one (Baltimore) are in the bottom 10 of NFL teams in pass defense, and seven of those teams are among the top 10 in the NFL in big plays allowed.
Tying together all of the data, it shows a strong correlation between the success of a passing defense and the frequency in which that defense relies on the blitz to apply pressure on opposing teams quarterbacks.
It further shows that the root of the problem often lies in the fact that those blitzing defenses are leaders in big plays allowed.
In fact, the top 10 pass defenses sport a sack to big-play allowed ratio as follows:
Baltimore – 1.86 Jacksonville – .9 Chicago – 1.3 Dallas - .82 Miami – 1.27 Cleveland - .72 New England - .89 New Orleans – 1.1 San Diego – 1.33 Philadelphia - .91
The bottom ten pass defenses sport a sack to big-play allowed ratios as follows:
Detroit - .65 Indianapolis - .86 Buffalo – 1.1 San Francisco – .73 Tennessee - .46 Houston - .70 Tampa Bay - .50 Denver - .89 Kansas City - .66 Cincinnati - .65
The issue is clear that teams who blitz often get beaten for big plays when the blitz fails – when the players removed from coverage don't reach the quarterback before he releases the ball, thus allowing for bigger plays to occur in a now depleted coverage unit.
But, what is the answer? What does a coach do when he cannot muster enough pressure on opposing quarterbacks without blitzing?
The answer may be found in teams like Cleveland, Dallas and St. Louis, who are in the top 15 in pass defense despite being ranked 24th, 26th and 15th respectively in the NFL in sacks.
What are they doing right?
Cleveland, Dallas and St Louis are forcing teams into long drives by not blitzing and not letting up big plays. Despite the low sack numbers (or perhaps in part because of them) they are ranked 12th, 4th and 10th respectively in big plays allowed.
While their third-down defenses are all among the bottom 10 in the NFL, they still manage to maintain solid pass defenses by requiring that opposing offenses consistently make shorter plays, rather than getting big chunks of yardage with big pass plays.
2005 Versus 2006 – What has Changed for Pittsburgh?
In 2005, Pittsburgh allowed 38 plays of 20+ yards – 14th in the NFL and had 47 sacks. Their sack to big-play allowed ratio was 1.24 (that would have been fourth in the NFL in 2006). Furthermore, 70% of those sacks came from non-blitzing personnel compared to 65% in 2006.
In 2006, Pittsburgh has allowed 46 plays of 20 yards or more, and their sack to big-play allowed ratio has dropped to .91 – down 25% from 2005. 46 plays of 20+ yards is an 18% increase over prior year, while their 42 sacks are five less than the prior year.
Simply stated, as the Pittsburgh Steelers are forced to blitz more to apply pressure on opposing quarterbacks, they are suffering for those more aggressive, risky strategies by allowing more big plays to occur.