FanPost

How important is the Offensive Line in the NFL passing game? A look at the numbers

Rich Barnes-USA TODAY Sports

Many Dolphins fans believe that Offensive Line play has dragged the team performance over the last 7 years. And just as many believe that the Offensive Line has been used as a scapegoat for poor QB play.

I thought it would be interesting to look at the factors that influenced the passing results in the NFL in general in 2018 and see what the numbers say. This post looks at the NFL as whole with brief references to the Dolphins.

The Importance of a Clean Pocket.

Usually great QBs are great because of what they do when the pocket is clean. Performance under pressure varies year by year and results under pressure are affected by factors unrelated to the QB.

https://www.pff.com/news/pro-pff-forecast-the-stability-of-play-from-a-clean-pocket-by-nfl-qbs

Here is the performance of the top ten QBs in the NFL in 2018 and their ratings with a clean pocket and under pressure. Grades and data obtained from PFF Premium Stats (subscription required).

Sample includes the 39 QB who took at least 20% of the snaps in the 2018 season.

Top 10 QBs by PFF passing grade

QB

Pass Grade

Rank

Rate Clean

Rank

Rate Press

Rank

Brees

94.0

1

125.6

2

79.5

11

Mahomes

92.7

2

134.2

1

70.4

22

Rivers

90.3

3

115.1

6

83.8

7

Luck

88.8

4

108.0

14

73.4

19

Brady

88.6

5

105.3

16

71.2

21

Rodgers

87.0

6

109.0

12

66.1

25

Wilson

84.6

7

122.1

3

86.2

5

Goff

84.3

8

117.1

4

59.8

29

Fitzpatrick

82.9

9

110.2

10

77.6

13

Mayfield

81.2

10

100.2

22

73.5

18

NFL Median

71.9

100.7

71.3

Notes:

Please note that the medians are measured against the whole 39 QBs in the sample and not just the 10 QBs above.

Passer Rating measures team efficiency more closely than it measures QB performance. But generally good QB have high passer rating. But Pro Football Focus has found that ratings with a clean pocket are more consistent than Ratings under Pressure.

In the NFL last year, the median rating with a clean pocket was 30 points over the rate under pressure.

Of the 10 QBs, nine of them were above average in passer rating with a clean pocket. But four QB were under the average in rating under pressure. That included the two QBs who played in the SB and 3 of the four QBs who played in the AFC and NFC Championships. (Brady, Goff and Mahomes were under the 71.2 average under pressure)

It is reasonable to assume that any QB would benefit from throwing the great majority of the snaps with a clean pocket.

The average QB in 2018 saw pressure on 34% of the snaps. Thought it would be interesting to see how much pressure the top QBs (ranked by passer rating) saw in 2018.

Top 12 QBs in Passer Rating-Pressure Rates

Quarterback

Passer Rating- All

% Pressure

Brees

115.7

25.69%

Mahomes

113.1

35.8%

Wilson

110.9

39.7%

Ryan

107.9

32.8%

Rivers

105.5

33.4%

Watson

103.1

44.8%

Wentz

102.2

31.3%

Goff

101.1

32.3%

Fitzpatrick

100.4

35.4%

Cousins

99.7

38.9%

Luck

98.7

29.5%

Brady

97.7

25.4%

NFL Median

93.7

34.0%

Notes:

I used Passer Rating because it correlates well with wins and points scored. Nine of the QBs in the table played in teams which made the playoffs. Matt Ryan had a really good offense but the defense let him down.

The Standard Deviation on % Pressure was 5.06%. Seven of the QBs saw pressures rates that were within one standard deviation from the Median

The other five included Watson, who was the most pressured QB in the NFL, and Wilson, who saw the sixth most pressures. Not coincidentally the two are running QBs who were able to extend plays and had high ratings under pressure.

On the opposite side you have Brees and Brady. They were second and 3rd lowest in pressures. Brees had the highest Passer Rating this year and playing from a clean pocket probably helped him a lot.

Andrew Luck was the other QB who benefited from an above average OL. He saw the 8th fewest pressures last year and did really well.

The overall correlation of Passer Rating to % of snaps under pressure was -0.30.

Factors that affect Pressure. It is not all on the Offensive Line.

Not all Pressures are the responsibility of the Offensive Line. Coaches and QB can limit the amount of pressures by protection adjustments and getting rid of the ball fast before pressures develop.

Protection adjustments are tough to quantify but ProFootball Focus measures the average time to throw and the % of throws made under 2.5 seconds. The latter measurement is the most important because sacks under 2.5 seconds are rare.

Trying to throw the ball fast requires more than a good QB as you need WR to get open quickly. Almost of the throws under 2.5 seconds will be made to the first read.

The Ten QBs who threw most often under 2.5 seconds.

Quarterback

Att under 25

% Under 2.5 sec

Rat under 2.5 sec

Sacks u 2.5 sec

Big Ben

428

60.3%

99.5

2

Flacco

223

56.9%

91.8

2

Beathard

105

56.1%

72.8

6

Foles

114

55.9%

109.0

3

Dalton

220

55.7%

99.3

5

Brees

282

55.3%

120.3

3

Rivers

299

55.0%

113.2

10

Manning

342

54.6%

98.0

14

Carr

330

54.5%

99.9

8

Driskel

110

54.2%

98.3

5

NFL Median

50.0

99.5

5

There were five QBs on the list above who played on teams that made the playoffs. Only three of them were above the Median Passer Rating under 2.5 seconds.

Interestingly Tom Brady, who has a reputation for throwing the ball fast, did not make the list. He ranked 12th at 53 with a 102 rating and five sacks.

Tannehill ranked really low on this list. He made 48.9% of the throws under 2.5 which ranked 26th.

He was sacked 11 times under 2.5 seconds. However, when he was able to throw under 2.5 seconds, he has the 7th highest rating at 109.4. It did not help the team too much.

For the NFL as a whole here is how throwing fast correlated with other factors

Corr % under 2.5 sec/Passer Rating

0.22

Corr % under 2.5 sec/Pressure Rate

-0.55

Corr % under 2.5 sec/Wins

-0.07

Teams who tried to mask the deficiencies in the OL by throwing fast a lot saw that they were able to reduce the pressure rates but that did not affect their win %. In many cases defenses were able to generate pressure and sacks even under 2.5 seconds.

How important is the Offensive Line?

Pro Football Focus ranks the Offensive Lines by Pass Blocking Efficiency. This takes into account Sacks, Hits and Hurries. Sacks are more heavily weighted than hits or hurries.

However. PFF does not attribute all sacks or hurries to the OL. For example, Big Ben was sacked 24 times and pressured 172 times. The Pittsburgh OL was charged with only 13 sacks and 134 pressures. Other sacks and pressures were attributed to other players. Big Ben was charged with 2 sacks and 24 pressures presumably because he took too long to get rid of the ball.

Teams with Highest PBE in 2018

Team

Pass Blocking Eff

Team Pass Rating

Pit

89.7

95.5

Chi

89.1

95.4

Bal

88.7

84

Cle

88.5

88.8

Atl

88.1

108

KC

88.0

113

NE

87.8

97.8

Phi

87.7

100.7

NO

87.4

112.3

Ind

87.2

98.2

LAR

86.5

100.7

Buf

85.7

62.6

Eight of the 12 teams with the highest PBE made the playoffs. Atlanta had a high PBE and a great offense that scored over 400 points but missed the playoffs because of the defense. The correlation between Team Pass Blocking Efficiency and Team Wins was 0.499. This was very significant.

Conclusions.

It is not all on the offensive line. There are a few QBs that have survived and thrived with poor pass protection. And good OL protection will not turn a poor QB into a good one.

Dolphins last year had a really bad Offensive Line which ranked 7th worst in Pass Blocking Efficiency. But that was far from the only problem as both of their QBs were below average when provided with a clean pocket.

But there is no question that good Offensive Line Play is an important ingredient of an NFL passing offense.

Comments and Questions about the article are welcome.

This is a FanPost and does not necessarily reflect the views of The Phinsider's writers or editors. It does reflect the views of this particular fan though, which is as important as the views of The Phinsider writers or editors.