Case Keenum was good at avoiding sacks in 2017

Pro Football Focus provides advanced quarterback metrics that tracks pressure percentage. Simply put, it is the percentage of times that a quarterback is pressured when he is throwing the ball.

Offensive coordinators can change this some by calling quicker passes that get the ball out of the quarterback’s hand quickly even if the offensive line is terrible, but generally the quarterback does not have too much agency in this stat. It is a function of the plays that are being called for him (or by him), the quality of the offensive line (or lack thereof) and the ability of the opposing defense to rush the passer.

The sack % is the percentage of dropbacks on which the quarterback is actually sacked. The difference between the sack % and pressure % is what I like to call sack avoidance %.

I calculate it this way:

1 - (sack%/pressure%)

Hypothetically a quarterback who was sacked every time he was pressured would have a sack avoidance % of zero percent while a quarterback who was never sacked would have a sack avoidance % of 100%. Here is the data from the 29 qualifying quarterbacks in 2017.

Note the Case Keenum was the second best quarterback in the league at sack avoidance last season. His offensive line in Minnesota was as bad the Broncos 2017 OL (arguably worse) so he was under pressure quite a bit (third highest pressure % in the league). The best quarterback in the NFL in 2017 at sack avoidance was Philip Rivers (which is way he was so frustrating to face - even when pressured he would somehow get the ball away and avoid the sack). The worst quarterback of the 29 qualifiers at avoiding sacks last season was Andy Dalton. He was sacked almost 75% of the time that he was pressured compared to Rivers who avoided the sack 78% of the time when he was pressured.

A couple of other interesting tidbits from this data: the two quarterbacks who saw pressure on the highest % of their dropbacks were Russell Wilson and Jacoby Brissett; Drew Brees was not pressured very much (lowest pressure%), but when he was he was not very good at avoiding sacks (second lowest sack avoidance%). Trevor Siemian was not pressured as much as we might think he was in 2017 (13th highest pressure%), but he was pretty bad at sack avoidance (4th worst in the league) when he was pressured.

I’m pretty certain it has been discussed before, but I am going to bring it back it here since it is relevant. Case Keenum was not only good at avoiding sacks last season, but he was also good at completing throws when under pressure. His completion% on throws under pressure of 55.7% was tops in the league in 2017. Better than Tom Brady. Better than Drew Brees. Better than Ben Roethlisberger.

His accuracy (a stat that takes into account dropped passes, hit-as-throwing, spikes and intentional throw aways) under pressure (69.2%) was tied for 5th in league (with Matt Ryan) and only behind Brees, Brady and Marcus Mariotta. Proving yet again, that Case Keenum was very good in 2017 (and not just lucky as some would like to characterize him).

Of course this doesn’t mean that he is going to be as good in 2018 as he was in 2017, but in general quarterbacks who are good at throwing under pressure (and avoiding sacks) stay that way. For example, Philip Rivers was 11th in 2014, 7th in 2015 and 3rd in 2016 in sack avoidance. Similarly, Andrew Luck was 1st in 2014, 4th in 2015 (if he had qualified) and 2nd in 2016.

Another example shows that this is skill that can be learned; Blake Bortles was dead last in sack avoidance in 2014 (getting sacks 85% of the time when he was pressured). He improved to 3rd from the bottom in 2015, then to 16th of 29 in 2016 and finally to 3rd best in 2017. In 2017 Bortles avoided sacks two out of three times that he was pressured which is a stark contrast to the one out of seven he avoided in 2014.