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Justin Fields Under Pressure: Reality vs Perception

Green Bay was far too successful in disrupting the Chicago Bears’ offense. As the team pivots to facing Tampa Bay, however, it’s worth taking popular metrics with a grain of salt.

Green Bay Packers v Chicago Bears Photo by Michael Reaves/Getty Images

Supposedly, according to Pro Football Focus, the Green Bay Packers managed 35 pressures against the Chicago Bears in their opening matchup, the second-highest number in the NFL (behind the Cowboys vs the Giants). This total suggests that the Bears allowed pressure on just under half of all offensive snaps, and emotionally that feels accurate.

PFF specifically listed Nate Davis as surrendering 9 pressures, Braxton Jones as surrendering 1, and the other members of the offensive line as giving up 5 apiece (for 25 total, with the other ten not being charged against the line). That breakdown should raise a few eyebrows, because almost anyone who has watched any tape breakdown should be curious how Lucas Patrick and Darnell Wright ended up being assigned the same number of pressures allowed. Of course, they also ranked Wright as the highest rookie tackle to play last week, so there might be some nuance involved.

However, there’s a number right there and so it has to be accurate, right? Well…maybe. While Pro Football Focus is usually the “first” name in the business when it comes to evaluating offensive line play, it’s sometimes worth looking around the other third-party evaluations in the business. This is especially true since PFF is a closed system unwilling to share their proprietary grading rubrics.

Meanwhile, my preferred database for football metrics is Pro Football Reference, and they use Sportradar game charting for their advanced statistics. Instead of listing 35 pressures (presumably mixed between passing attempts and running plays), Pro Football Reference lists nine for passing plays alone. In order for both of the totals to be consistent, then, the Bears need to have allowed 26 pressures on their 29 rushing attempts (7 of which were designated as scrambles off of pass plays by PFR). In other words, pressures allowed (or generated) are really not consistent between raters. They are frequently open to interpretation.

Pro Football Reference’s charting actually says that the Bears’ offensive line created an average of 2.8 seconds of pocket time, which is tied for the second-most in the league. Of note, the Bears faced 14 blitzes against a mix of 37 pass attempts, 4 sacks, and 7 scrambles (in other words, they were blitzed on 29% of plays that were likely designed as passes). That’s the 12th-highest rate in the league. However, they only allowed pressure on 18.8% of drop backs, which is the 20th-highest rate in the league. In other words, these numbers suggest that both in terms of how long the pocket held up and whether or not the line surrendered pressures, the crew led by Braxton Jones and Darnell Wright actually did fairly well. Not “good” well, but thoroughly middling well. Despite facing more pressure than average, they were 13th in the league in terms of preventing that pressure from reaching the quarterback. That’s far from the second-worst in the league claimed by Pro Football Focus.

Despite this, only five teams allowed more sacks, and the conventional sack rate was just below 10% (the tenth-highest in the league). In simple terms, while the line did not allow an unusual amount of pressure, more of those pressures turned to sacks than normal (44%, or the eighth-highest rate in the league). This is not good, and it suggests that a factor besides the overall play of the line is at work.

ESPN also has their own metric based on NFL Next Gen Stats, “Our pass rush win rate metric tells us how often a pass-rusher is able to beat his block within 2.5 seconds.” This statistic can be problematic at times, because it needs to record the pass-rusher as engaged in the play, and so it is possible for it to give inaccurate readings. That said, Braxton Jones was listed as winning his own blocks 97% of the time while being double-teamed on 30% of passing plays, good for 8th among tackles. Additionally, they had the Bears as a whole winning 61% of their pass-blocking assignments, which is good for 14th in the league. That number is consistent with the ranking suggested by Pro Football Reference’s numbers. Additionally, the Bears also were given the 5th-best win rate for run blocking, suggesting that the offensive line was not profoundly lopsided in its ability.

Why, then, does Pro Football Focus disagree? A number of reasons present themselves. One obvious answer is that it is possible that Justin Fields is making his line look better by staying alive in the pocket longer and avoiding pressure. However, PFR at least claims to track times “when the QB is forced to throw the ball earlier than intended or is chased around/out of the pocket as the result of defensive pressure” with its hurried measure. That explanation also does not account for the high number of pressures that are turning into sacks.

Another answer is that Justin Fields is taking longer than 2.5 seconds to catch the snap, drop back, read the defense, and throw the ball. That would mean that his blockers are “winning” for the average circumstance, but not for the ones they find themselves in. In fact, NextGen Stats reports that Fields averaged 2.95 seconds to throw on all pass attempts exclusive of sacks (7th-highest in the league). Thus, his offensive line might be “winning” per NextGen Stats’ instruments, and they might even be allowing the 2.8 seconds that nearly leads the league according to PFR, but the defenders are still reaching him. It might be telling that Pro Football Reference only lists one throwaway for Fields on 37 pass attempts.

So far, it’s only one game. However, when the difference between success and failure takes place in tenths of a second, and the total span of time to throw between the quickest and slowest passers is less than a whole second, the eye test likely fails when used by itself. Likewise, using a single closed-box evaluation (that also relies on a rater’s judgment) is not going to offer as much insight as looking at more of the available data.

One way or another, the offensive line is not good enough for the task that it has been given. It is certainly responsible for much of the pressure that Fields is facing. However, it is also accurate to say that as a whole, it is up for debate as to how much pressure it is allowing outside of the norm and whose fault it is for the rate at which that pressure is resulting in sacks. At least two independent sources claim that the line is no worse than average, and all three sources seem to be in agreement that the interior positions are weaker than the tackles.

It will be interesting to see how this next week plays out, because no matter whose fault it is, the offensive line and Justin Fields need a better performance.