Did the Broncos offensive line improve in 2019 relative to 2018?

The 2018 Denver Broncs offensive line had six different starting line-ups with the one line-up being employed four times at the start of the season and then another being employed seven times at the end of the season.

The 2019 offensive line was much more stable with one line-up starting 10 games and the most any other staring combination was used was two games.

You should notice that our LT-LG-C trio made every start together and played almost every snap on offense. So if nothing else, the 2019 OL was more stable than the 2018 OL with only five variations being employed. If you combine Garett Bolles, Dalton Risner, Connor McGovern and Elijah Wilkinson you find that they played 95% of the possible snaps at their four positions on the offensive line. If you remember that Ja’Wuan James did not play much in his three starts, we essentially had the same offensive line for the first twelve games. It was only the last four games where thinks got crazy with the injuries to Ron Leary and Elijah Wilkinson. That is good insofar as playing next to someone on the OL can help communication on double teams in the run game and switching on twists in pass protection.

So let’s turn to the rankings. First we will focus on the footballoutsiders.com run game rankings. I find their whole OL rankings to be the most thorough. Note that this analysis of the running game does NOT look at average yards per carry since that is skewed heavily by the running back’s ability to gain yards in the second level and beyond which has very little to do with the offensive line. Football outsiders take that into account in these rankings - in adjusted line yards, ALY, particularly.

You can see that the 2018 OL and the 2019 OL were both good at run blocking. The 2018 OL was better in terms of ALY while the 2019 OL was significantly better at not having runs get stuffed. Only the Dallas and Baltimore offensive lines were better at avoiding stuffed runs. League average was 19 percent. Miami was league worst at 26 percent in 2019.

So how did the 2019 OL compare to the 2018 OL in terms of pass protection? According to FO, the 2018 OL was 11th in adjusted sack rate (which gives sacks [plus intentional grounding penalties] per pass attempt adjusted for down, distance, and opponent). The 2018 adjusted sack rate was 6.3 percent. The 2019 OL was much worse with an adjusted sack rate of 8.1 percent which was 25th in the NFL. Part of this increase in adjusted sack rate could be blamed on Joe Flacco, who was holding onto the ball too long and took sacks as a result, and Brandon Allen, who didn’t seem to have much of a feel for the pocket. Drew Lock was actually the second hardest QB in the league to sack in 2019 (minimum 50 dropbacks). He was sacked on only 2.825 percent of his dropbacks. Only Matt Schaub was sacked at a lower rate 2.817 percent.

For comparison, Flacco was sacked on 8.15 percent of his dropbacks and Brandon Allen on 8.41 percent of his. Both Flacco and Allen were near the bottom of the league in sacked percentage while Lock was almost at the top of the league and all three ostensibly played behind the same offensive line (see above for who was starting in the games where each QB started - Flacco 1-8, Allen 9-11, Lock 12-16).

In terms of pressure percentage allowed, the 2018 Bronco OL allowed 162 pressures on 632 dropbacks (586 passing attempts, 12 scrambles and 34 sacks) - not counting the passing attempts from Emmanuel Sanders and Colby Wadman. That is pressure on 25.6 percent of dropbacks. The 2019 OL allowed pressure on 25.5 percent of dropbacks. So while the adjusted sack rate may have gotten worse year over year, the frequency with which the offensive line allowed pressure was almost unchanged. That value of 25.5 percent was 24th in the league in 2019. The Saints were the best OL allowing pressure on only 16.1 percent of dropbacks, while the Jets allowed pressure on 30.5% of their dropbacks. From an absolute numbers perspective the Dolphins allowed 203 QB pressures which was the highest value in the league while the Ravens allowed an astounding 84 total pressures in the regular season.

Comparing our three quarterbacks in 2019 you find that Flacco was pressured on 28.1, Allen on 19.4 and Lock on 24.2 percent of their respective dropbacks. So Allen was pressured the least frequently of our QBs, but sacked the most frequently. A full fifty percent of his pressures resulted in sacks. That was the worst figure in the league (minimum fifty dropbacks). For comparison 32.1 percent of the time that Flacco was pressured he was sacked, while only 12.8 percent of Lock’s pressures resulted in a sack. That 12.8 percent was second best in the league. Only Ben Roethlisberger was more difficult of sack when he was pressured (11.1 percent).

So it would appear that in the aggregate the offensive line in 2019 performed about the same as it did in 2019. The run blocking improved in some facets and regressed in others as did the pass protection. Drew Lock’s pocket awareness and mobility helped the offensive line during his five 2019 starts. I would expect that having him as the starter for (hopefully) 16+ games in 2020 should lead to significantly improved pass protection stats.

Teams can win while allowing frequent pressure on the QB, as you can see from the rankings of the Vikings (22nd), Titans (27th) and Seahawks (30th) in pressure percentage allowed. That being said, keeping your QB from getting pressured does not correlate with making the playoffs as the Rams (3rd), Cowboys (4th) and Bengals (6th) can attest. In fact only three of the top ten ranked teams in pressure percentage allowed made the playoffs - go figure.