How Brock Osweiler's Proneness to Sacks Impacts Denver
Some time in the third quarterback of the Denver Broncos’ Week 14 game against the Oakland Raiders, the Denver offensive line forgot Oakland's defensive end Khalil Mack existed.
That, or they knew he was there and couldn’t do anything about it.
Mack had five sacks, all in the second half of the game and all while getting a one-on-one matchup off the line of scrimmage. Of his five sacks, three came on second down to set up a third and long and two came on third down, one of which resulted in a strip sack and safety in the Denver end zone.
By our Net Expected Points (NEP) metric, Mack was the second most valuable Oakland player from just his five sacks alone. NEP measures the value of each play on the field based on how an average team would be expected to score in each scenario using historical data. Mack’s sacks took away 5.57 NEP from Denver on offense, which was just below the 5.80 NEP tight end Mychal Rivera was worth on offense for Oakland, the highest for any player in the game.
Using win probability, no player had a bigger impact on the game than Mack. His five sacks netted a 50.07 percent swing in win probability throughout the game, per the metrics from numberFire Live.
While Mack single-handedly took over the game on Sunday, his performance only added to a growing concern for the Broncos team, which has been the offensive line.
After the game, Mack didn’t talk about his ability to get past the tackles, though. He suggested it had more to do with the quarterback.
Raiders OLB Khalil Mack on his big day: "(Brock) held the ball a lot longer than Peyton did."
— Cameron Wolfe (@CameronWolfe) December 14, 2015
Keep Holding On
Mack might not be wrong here.
While offensive linemen can greatly influence how much pressure can get to a quarterback, there is some evidence the sacks themselves are more of a quarterback stat than a line stat. To Mack’s point, just this year there’s been a considerable difference between Peyton Manning and Brock Osweiler after the snap.
Even before Sunday’s game against Oakland, Osweiler had been sacked at a much higher rate than Manning. Osweiler had been sacked on 9.2 percent of his drop backs this year, while Manning had been dropped on 4.5 percent. After getting sacked five times on Sunday but dropping back 56 times, Osweiler actually decreased his sack rate to 9.1 percent.
Clearly, there is offensive line influence on sacks. It’s a reason why Manning was getting dropped at a near-career-high rate. Manning’s sack rate hasn’t been above four percent for a season since 2001 when it hit five percent during the fourth season of his career.
Manning, over his career, has been one of the best quarterbacks at getting the ball out quickly to avoid getting hit for a loss.
Osweiler, in his first turn as a starting quarterback, hasn’t gotten there yet.
The question here remains: how much of that really matters? During their time under center -- in Manning’s case more pistol and shotgun -- the two have lost almost exactly the same value on sacks taken.
On plays when Manning has been sacked, the Broncos have lost 28.23 NEP and on plays when Osweiler has been sacked the Broncos have lost 23.90 NEP. On a per drop back basis, that gives Manning a slight edge on those plays, but across all drop backs, Osweiler has still been much better statistically.
Manning’s Passing NEP per drop back is still among the league’s worst at quarterback, and despite not playing since Week 9, he still leads the league in interceptions with 17 -- Matt Ryan is second with 14.
Osweiler has measured much better in his appearances, with a Passing NEP per drop back of 0.06, though that is still below the league average among quarterbacks with at least 100 drop backs this season of 0.12. Much of that value has been driven by Osweiler’s ability to avoid interceptions. He’s thrown a pick on just 1.8 percent of his attempts, a much better figure than Manning’s 5.3 percent.
Staying away from interceptions with safe throws has been a popular way to break in new quarterbacks over the past few seasons, and it’s very the much route Gary Kubiak is taking with Osweiler under center. The problem there, though, can lead to a much lower ceiling for the offense, and in games like Sunday when the quarterback is asked to throw often, it can lead to little reward.
On Sunday, Osweiler finished the game with zero touchdown passes on 51 pass attempts, the 52nd time a quarterback has thrown at least 50 passes and no touchdowns since 1965, and he’s just the sixth member of that group to do so without also throwing an interception.
Osweiler’s Passing NEP for the day was -5.57, the exact NEP taken away from Mack’s five second half sacks. That also means he provided zero value over his 51 pass attempts.
But zero value does not mean average (again, the average Passing NEP per drop back of quarterbacks with at least 100 drop backs is 0.12).
Games like this, when little value is added in the passing game, are when those sacks are going to matter most.
In this version of the Denver offense, one more like the ideal Kubiak system, Osweiler is waiting for receivers to get open before he throws the ball. Based on the results so far, he’s not yet a good enough quarterback to throw some of these receivers open and create bigger plays on his own.
That’s caused him to hold the ball longer and, as Mack pointed out, made him more vulnerable to hits. On top of some missed throws and dropped interceptions during his starting gig so far, that value could go downhill quickly.
Denver’s next three games come against the Pittsburgh Steelers, Cincinnati Bengals and San Diego Chargers. Pittsburgh ranks 8th in defensive sack rate, and Cincinnati ranks 12th. The Chargers are 24th, and haven’t done much of anything on defense for most of the season.
Some of these concerns can be counteracted with a better run game, one that was nonexistent against Oakland but had been better against the opponents in Osweiler’s first three starts. It’s expected Osweiler will start next week against the Steelers, but it’s still up in the air if Manning could return afterwards.
Sacks might not be the biggest reason the Broncos turn back to a healthy Manning -- if they do -- but they’re exposing part of what could be a bigger problem in an Osweiler-led offense.