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Bears Must Address Imbalanced Roster Construction

| November 20th, 2020


Yet again in 2020, we see that the Bears have one of the best defenses in the NF,L coupled with one of the worst offenses. This combines to give them a team that is not good enough. It’s Groundhog Day all over again, a continuation of 2018-19, all of the Lovie years, and the 1980s after Jim McMahon got hurt.

Normally I’d use the bye week to do an in-depth look at the numbers for Chicago’s offense and defense, but honestly I don’t see the point. Their defense is really good, their offense is really bad, and you don’t need advanced stats to tell you more than that. I’m sure I’ll still do some of that analysis in the offseason but for right now I want to focus on a bigger question: WHY is the defense so much better than their offense?

The answer here is really not that surprising: the Bears are investing more in the defense. The table below shows how much money they have invested in the defense compared to the offense, as measured in 3 ways:

  • 2020 cap dollars. How much current money is being spent.
  • Average yearly salary. This accounts for the fact that contracts don’t have even distribution of cap hits every year. For instance, Robert Quinn has an average salary of $14M per year in his contract, but only has a 2020 cap hit of $6M. This will give a better picture of true spending.
  • % of salary. This looks at how much of your total spending is focused on one side of the ball, based on the average annual salary of players. It’s a good measure of how lopsided your investment is on offense vs. defense.

The table below shows the Bears’ values for offense and defense in each category, as well as the NFL average and where the Bears rank. All data is from Spotrac.

A few thoughts:

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Bears at the Mini-Bye Volume III: Defense & Playoff Odds

| October 15th, 2020

I already looked at a variety of statistics for the offense, including QB performance, run game woes, and explosive plays, and explored how Chicago has deployed their skill position players. Today I want to look at advanced defensive statistics from Pro Football Reference and think about Chicago’s playoff odds.


Missed Tackles

I highlighted missed tackles as a concern in the secondary heading into the season. As a team, the Bears are actually doing quite well with missed tackles right now; they rank 7th in the NFL with 22 through 5 weeks. The table below shows missed tackle stats (from Pro Football Reference) for all players with at least 10 tackle attempts, as well as cumulative totals for each position group.

For context, here’s how the positional averages compare to NFL peers over the last 2 years:

  • The median starting NFL DB misses right around 11% of their tackles, so Chicago’s secondary is about average here so far. That’s actually pretty good for them given the tackling concerns heading into the season with Kyle Fuller, Buster Skrine, and Eddie Jackson. Fuller in particular has struggled so far this year, but everybody else has been ok.

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Bears at the Mini-Bye Volume II: Offensive Personnel Usage

| October 14th, 2020


I already looked at a variety of statistics for the offense, including QB performance, run game woes, and explosive plays. Today I want to explore how the Bears are deploying their skill position players, using lineup data from the NFL Game Statistics Information System. This tracks how many plays the Bears have played with different combination of 11 offensive players, and splits the data into runs and passes, with yards gained for each. Combing through this data can provide valuable insights into how the Bears are deploying their personnel, and what packages have been most and least effective.


Tight Ends

The Bears completely overhauled this position in the offseason, following a disastrous 2019 campaign in which no player even hit 100 receiving yards. They gave Jimmy Graham a big contract, spent their 1st pick (43rd overall) on Cole Kmet, and brought in veteran journeyman Demetrius Harris.

I want to start by looking at Cole Kmet, who has been very quiet so far as a rookie despite receiving a good bit of training camp hype. Through five games, Kmet has played 102 snaps, seen 3 pass targets, and caught 1 ball for 12 yards. This is hugely disappointing, and worrisome for his future; when I looked at rookie seasons for TEs drafted in the 2nd round this offseason, I found that tight ends who are going to be good are typically involved in the offense right away. The only tight ends drafted in the 2nd round over the last 10 years to receive fewer than 30 targets in their rookie seasons are Vance McDonald, Adam Shaheen, Gavin Escobar, Drew Sample, and Troy Niklas. Of those, only Vance McDonald has done anything in the NFL. Kmet is currently on pace for 10 targets.

It’s fair to argue a rookie should see their production increase as the season wears on, so I looked at all 19 players in that study through the first five games of their rookie season. You can see the full list here, but Kmet has the 3rd fewest targets, least amount of catches, and the least number of yards through that time period. And for all of those categories, the bottom four (not including Kmet) are from the list of five names above. It’s early, but right now Kmet most closely resembles Troy Niklas and Adam Shaheen, which is very not good.

Because I was curious about Kmet, I split out lineups involving him vs. those who don’t, and also sorted by the number of tight ends on the field. The results, as you can see below, are certainly illuminating.

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Bears at the Mini-Bye Volume I: Offense

| October 13th, 2020

We’re five weeks in to a wild season in which we’ve already seen the Bears make a quarterback change and post three comeback wins from 13 or more points down. Since they’re on a mini-bye following their Thursday night victory over Tampa Bay, now is a good time to take a step back and see what we’ve learned so far.

Obligatory warnings:

  • These are still small sample sizes, especially given that each QB basically played 2.5 games. So think of any lessons learned here more as observations that are worth monitoring going forward than hard and fast conclusions.
  • Statistics for Bears are updated through 5 games, but all other teams only have 4 at the time of this writing, so NFL ranks may have changed a bit by the time this is published.

I have a lot I want to get to, so let’s dive right in.


Better Lucky Than Good

The Bears may be 4-1, but I don’t think anybody would argue they have played well so far this year (including Matt Nagy). As you can see from the pie chart below, which shows the % of offensive snaps the Bears have taken in a variety of score situations, they have actually spent the majority of the season trailing.

They’ve taken 2/3 of their offensive snaps while trailing (33% by 2 or more scores) and only 19% with a lead. To somehow go from that to 4 wins in 5 games is remarkable, but it should not be expected to continue going forward. The Bears need to play better if they want to keep winning games. The good news is that they started to look better in week 5; the defense in the 2nd half looked the best it had since week 4 of the 2019 season, and the offense was something approaching competent for the last 40 or so minutes of the game.


QB Comparison

The Bears switched from Mitchell Trubisky to Nick Foles in the 2nd half of week 3, which means both QBs have actually played a similar amount of snaps so far this year (Foles is at 168, Trubisky 169). Let’s see how each performed. The table below shows stats for each passer, as well as the average for the entire NFL this year, broken up into deep and short throws (anything that travels 15+ yards in the air past the line of scrimmage is considered deep). YPA = yards per attempt.

A few thoughts:

  • Keep in mind that Nick Foles has played 2 of the best defenses in the NFL the last 2 weeks, while Trubisky played all of his snaps against 3 of the worst defenses in the league. Still, it’s hard to argue Foles has been better so far, at least on a statistical basis. He needs to play better going forward.

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Trubisky Will Start. So What Do the Bears Need From Him?

| September 6th, 2020

Friday night, news leaked that Mitchell Trubisky would be the Bears’ week 1 starting QB. While this is a decision that greatly surprises me, I want to explore what the Bears need from Trubisky in order to make it work.

This immediately led me to look for what he has done differently when he has been the most successful in his Bears career. There was actually a stretch in 2018 when he performed pretty well, starting with his breakout game against Tampa Bay in week 4 and continuing until he hurt his shoulder against the Vikings in week 11. In that 7 game stretch, Trubisky was 138 of 217 for 18 TD, 6 INT, and a 107.3 passer rating. Not every game in there was good – he had 3 games with a passer rating below 80 – but overall it was easily the most impressive stretch of his career, as you can see below (note: I’m ignoring his rookie season in 2017 and focusing solely on what he has done in this offense the last 2 years).

Three things stand out to me here:

  1. He moved the ball efficiently. Look at that yards/attempt; it’s beautiful. For context, the average NFL pass gained 6.7 yards in 2019. Trubisky was well above that for one magical seven game stretch, but has been below it for the rest of his career. And this isn’t just a one-game outlier; Trubisky was above 10 yards/attempt in three of the 7 games, and only below 6.5 in one of them. For a little more context, 8.7 yards/attempt would have ranked 2nd in the NFL last year, while Trubisky’s 6.1 yards/attempt was last in the NFL among qualified quarterbacks.
  2. He threw touchdowns. 4.5% of all passes thrown in the NFL in 2019 went for touchdowns. In that seven game stretch, Trubisky was nearly double that. Even if you remove the Tampa Bay game as an outlier, he’s still at 6.3% for the other 6 games, which is well above league average. For the rest of his career, he has struggled mightily to throw touchdowns.
  3. His legs were a weapon. This has more to do with running efficiency than volume, though you can see he also ran more often when he was at his best. From weeks 4-11 of 2018, Trubisky averaged over 8 yards/carry, while he was around 4 yards/carry in the other samples.

Those are the differences. Trubisky didn’t throw it more or less often than in other times, he didn’t complete more passes, and he didn’t avoid interceptions. He just gained more yards, threw more touchdowns, and ran it more effectively.

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Grading the 2020 Chicago Bears Roster: Defense & Specials

| July 28th, 2020


Defensive Line: 7

Key Players: Akiem Hicks, Eddie Goldman, Bilal Nichols, Roy Robertson-Harris

Roster Depth: Brent Urban, Abdullah Anderson, John Jenkins, Trevon McSwain, Lee Autry

I went back and forth between a 7 and an 8 for this one. Akiem Hicks is a monster, assuming he can return to his pre-injury form in 2020. Eddie Goldman is a really good run-stuffing nose tackle, and Roy Robertson-Harris provides some nice juice as a situational pass rusher.

The wild card here is Bilal Nichols, who took a step back last year after a promising rookie season in 2018. If he can step up, this group should be really good. If he doesn’t, then they look a bit more like Hicks and a bunch of situational pieces. Brent Urban and Abdullah Anderson are both fine end of the roster players who won’t get pushed around too badly against the run but don’t offer much as pass rushers.


Edge rushers: 9

Key Players: Khalil Mack, Robert Quinn, Barkevious Mingo

Roster Depth: Trevis Gipson, Isaiah Irving, James Vaughters, LaCale London, Ledarius Mack

Mack and Quinn are the headliners here, as the duo might be the best pass-rushing tandem in the NFL. Just don’t look too closely at the depth behind them, because it’s ugly. Mingo is a suitable coverage player and run defender, but offers nothing in the way of pass rush. Nobody else has any notable NFL experience.

If Mack and Quinn stay healthy, this is one of the best groups in the NFL. If one (or God forbid both) of them gets hurt, the Bears are in trouble.


Inside linebackers: 7

Key Players: Danny Trevathan, Roquan Smith, Joel Iyiegbuniwe, Josh Woods

Roster Depth: Rashad Smith, KeAndre Jones

Stop me if you’ve heard this before: the starters are really good, but the depth is scary. Trevathan in particular is a really solid, smart player, while Roquan Smith has flashed all-pro ability through two years but needs to be more consistent. Both players ended 2019 on injured reserve and need to stay healthy this year, because the guys fighting for time behind them haven’t done much outside of special teams. Nick Kwiatkoski and Kevin Pierre-Louis, who both played very well for extended stretches in 2019, are gone.

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Grading the 2020 Chicago Bears Roster: Offense

| July 27th, 2020

Camp is here, which means it’s time for me to grade the roster. Like I did last year, I’ll grade on a 1-10 scale, with 1 being the worst in the NFL, 10 being the best, and 5 being an average NFL unit. Let’s get right down to it.


Quarterback: 3

Key Players: Mitchell Trubisky, Nick Foles

Roster Depth: Tyler Bray

Mitchell Trubisky was one of the 5 worst quarterbacks with significant playing time in the NFL last year. Nick Foles is on his 3rd team in 3 years and hasn’t started more than 5 games in a season since 2015. The Bears don’t have a good quarterback on the roster, which is a real problem in a quarterback-driven league.

If I were grading just on the starter, this would be a 2. But the Bears are probably going to end up with one of the worst starters and best backups in the NFL, so the better depth bumps it up slightly.


Running back: 3

Key Players: David Montgomery, Tarik Cohen

Roster Depth: Ryan Nall, Artavis Pierce, Napoleon Maxwell

David Montgomery struggled as a rookie, averaging only 3.7 yards/carry and failing to establish himself in the passing game, which was supposed to be the reason why the Bears traded up for him after getting rid of Jordan Howard. Tarik Cohen followed up a stellar 2018 with the worst season of his career. I think both of these players have the potential to be really good in 2020, but neither was last year, so it’s hard to be super confident in them right now.

Still, I might be willing to give them a 4 as the “starters,” but the atrocious roster depth knocks this down a peg. All 3 backups are undrafted players who have yet to show they can do anything in the NFL. If David Montgomery gets hurt, the Bears don’t have a runner on the roster who you can reasonably trust.

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Advanced Defensive Stats: Pass Rush

| July 14th, 2020

I’m continuing to look at Chicago’s defense using advanced defensive statistics from Pro Football Reference (PFR). I already looked at missed tackles and coverage, and today I want to look at pass rush.


Expected Sacks

In general, sacks are fairly variable from year-to-year due to their small sample size. Accordingly, they are not a very good way to evaluate a pass rusher, just like rushing or receiving touchdowns (which also have a small sample size) are not the main way we evaluate skill position players.

This is where advanced statistics can give us a more helpful overall picture of a pass rusher’s performance. The PFR database tracks total QB pressures, which gives you a larger sample size and thus should be more reflective of the player’s performance.

I was curious about the relationship between total pressures and sacks, so I took the following steps to investigate:

  • I examined all rushers between 2018-19 (the only 2 years this database has) who had at least 15 pressures in a year; I chose this threshold to look only at full-time pass rushers. This gave me a data set of 215 seasons, or roughly 3.4 rushers per team per year.
  • I found that the typical ratio was 3.8 pressures per sack, though this had a very high standard deviation (4.0), highlighting how much it varies from person to person.
  • When I looked only at 30+ pressures in a season (63 samples, so roughly 1 player per team per season), the average stayed virtually identical at 3.7 pressures per sack, but the standard deviation dropped to 1.2. This suggested to me that the typical number of around 3.8 pressures/sack is legitimate, and the high standard deviation with the 15 pressure cutoff was largely due to small sample sizes; you get lots of fluctuation in pressure/sack ratio when the pressure number is small.

Using that 3.8 pressures/sack as the norm, then, you can come up with how many expected sacks a player has for a season. If a player has 38 pressures, they are expected to have 10 sacks (38/3.8). You can then easily get a sack differential; a player with 10 expected sacks who actually posted 7 would have a differential of -3, indicating they were 3 sacks below what they should have normally had.


2019 Bears

I included all DL and OLB who registered pressures in 2019, as well as Robert Quinn and Barkevious Mingo. Players with a sack differential of +1 or better are highlighted in green, while those with a sack differential of -1 or worse are highlighted in red. I also included 2018 data to give you an idea of whether 2019 results were consistent with the year before.

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Advanced Defensive Stats: Coverage

| July 9th, 2020

I’m continuing to look at Chicago’s defense using advanced defensive statistics from Pro Football Reference (PFR). I already looked at missed tackles, and today I want to look at coverage.


Baseline Rates

There are a whole host of advanced coverage stats available, including completion percentage, yards/target, target depth, yards after catch allowed, TDs, INTs, and passer rating. In order to keep it simple, I’m going to look only at yards/target, as that is a good baseline metric for how effective teams are when targeting a player. I’m intentionally not looking at passer rating because that gets skewed by touchdowns and interceptions, which are notoriously random statistics within a small sample size like this.

I compiled all yards/target stats from the PFR database for 2018 and 2019, the only 2 years it has, and sorted them by position. In order to compare starters to starters and avoid rates skewed by backups, I assumed a base nickel package of 4 defensive linemen (DL), 2 linebackers (LB), 3 cornerbacks (CB), and 2 safeties (S). For all 32 teams over a 2 year span, this would mean 128 LB, 192 CB, and 128 S. This gave thresholds of 30 targets for LB, 40 for CB, and 20 for S.

Looking at those sample sizes, you can see the spread of missed tackle rates in the table below for each position group.

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Advanced Defensive Stats: Missed Tackles

| July 1st, 2020

I’ve written quite a bit about Chicago’s offense so far this offseason, but not as much about the other side of the ball. I want to change that in the next series of articles, using advanced defensive statistics from Pro Football Reference (PFR). We’ll start today by looking at missed tackles.


Baseline Rates

Let’s start by establishing a baseline for what is a normal rate of missed tackles.

I compiled all missed tackle stats from the PFR database for 2018 and 2019 (the only 2 years it has) and sorted them by position. In order to compare starters to starters and avoid rates skewed by backups, I assumed a base nickel package of 4 defensive linemen (DL), 2 linebackers (LB), and 5 defensive backs (DB). For all 32 teams over a 2 year span, this would mean roughly 256 DL, 128 LB, and 320 DB. This gave thresholds of 20 tackles for DL, 60 for LB, and 40 for DB.

Looking at those sample sizes, you can see the spread of missed tackle rates in the table below for each position group.

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