Will the Bears Defense Regress in 2019?

[soulman]

Will the Bears Defense Regress in 2019? History Tells Us…Not So Much.

Johnathan Wood | July 15th, 2019

https://dabearsblog.com/2019/should-we-expect-chicagos-defense-to-regress

Chicago’s defense was really, really good in 2018. They led the NFL in points allowed, turnovers forced, touchdowns scored, and passer rating against, and finished 3rd in both yards and sacks. They finished as the runaway best defense in Football Outsiders’ DVOA, which is intended to be an all-encompassing metric, and even finished as the 8th best defense ever in DVOA’s database, which runs back to 1986.

Now as we head into 2019, fans are rightly wondering if Chicago’s defense can repeat that performance. While I won’t pretend to be able to predict the future, I can look at the past to see what it might have to tell us. So I looked at top defenses in recent NFL history and measured, through a variety of metrics, where the 2018 Bears excelled. Then I looked to see how they followed that up in the next season. Full data collected can be viewed here for transparency’s sake.

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DVOA

The DVOA system is set up such that an average defense gets a score of 0, with negative numbers indicating you are better than average (the farther from 0 the better). The Bears finished with a final score of -26.0, so I looked at other teams in the last decade (2008-17) who finished at -20 or better. This was quite a small list, as it featured only 10 teams. Here’s how they fared in the season following that dominant performance:

• Average DVOA: -25.1%
• Average following DVOA: -8.8% (8th in NFL)
• Change: 16.4%
• # teams with better DVOA following year: 0
• # teams top 5 in DVOA following year: 5
• # teams top 10 in DVOA following year: 8
• # teams below average in DVOA following year: 1

First, notice that none of these defenses were as good the following year. This isn’t surprising; there were only 10 teams in 10 years who achieved this caliber of DVOA. The odds of doing that twice in a row are very low.

 

But that doesn’t mean the defenses were bad. Half of them were among the top 5 in the NFL the following year, and 80% of them were top 10. Only one ended up being below average, and that one should be very familiar to Bears fans, as it’s the 2013 squad that completely fell apart after Lovie Smith left and Brian Urlacher retired. That defense lost 3 starters (Urlacher, Nick Roach, Israel Idonije) and had a host of other players on the tail ends of their career who fell apart following 2012. The current Bears are not remotely in that same situation.

If you want to get even more narrowed down, only 5 of these 10 teams had a DVOA of at least -25, which the Bears did in 2018. Every single one of them finished as a top 10 defense the next year, with an average of being around the 5th best defense in the NFL. It turns out that historically good defenses remain good the next year. Shocking, right?

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Points Allowed

Now let’s look at teams who finished similar to the Bears in points allowed. Chicago gave up 17.7 points/game (PPG) last year, so I looked at all teams who gave up less than 18 PPG from 2008-17. This is a bit more difficult of a stat to compare across time since scoring has generally gone up over the last decade, but it’s at least some way to narrow it down, and the sample size here was 33 teams.

• Average PPG : 16.2
• Average following PPG: 20.1 (10th in NFL)
• Change: 3.9
• # teams with better PPG following year: 4
• # teams top 5 in PPG following year: 13
• # teams top 10 in PPG following year: 22
• # teams below average in PPG following year: 7

Here we see similar trends to DVOA. Most – but not all – of the teams fared worse the next year, but they were still generally pretty good. The average defense finished around 10th in points allowed the following year, but that was a lopsided distribution, as 2/3 of the teams finished within the top 10, and over 1/3 of them in the top 5. There were a few bad apples (including the 2013 Bears) who were just really bad the next year that dragged the overall average down.

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Turnovers

Finally, let’s look at teams who forced a similar number of turnovers as the 2018 Bears, who had 36. This was actually the first time since 2015 that anybody in the NFL forced 35 or more, but 16 teams overall reached that mark between 2008 and 2014.

• Average turnovers: 38.2
• Average following turnovers: 26.9
• Change: 11.3
• # teams with more turnovers following year: 0
• # teams top 5 in turnovers following year: 4
• # teams top 10 in turnovers following year: 8
• # teams below average in turnovers following year: 5

Here we see a bit more of a drop-off. Fewer teams remained at or near the top of the league – though 1/4 were still top 5 and 1/2 top 10 – and the overall average rank the next year was 13th, which isn’t that far from the NFL average (16th-17th for a 32 team league). It makes sense that turnover numbers would fluctuate more than other statistics, as we’re talking smaller sample sizes with fewer turnover plays than points scored or total plays (which all factor into DVOA).

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Conclusions

No matter how you look at it, the odds of Chicago’s 2019 defense being as good as their 2018 version are very slim. That’s what happens when you have a historically good year.

But that doesn’t mean their defense is going to be bad. The overwhelming majority of defenses in these samples remained very good the year after their dominant performance, especially when using more all-encompassing metrics like DVOA and points scored.

And here’s the other thing to keep in mind: Chicago’s defense was so much better than other groups in the league in 2018 that they can afford to regress some and still remain the best defense in the NFL. The difference between their DVOA and the 2nd best defense was greater than the difference between 2nd and 10th. The same is true for turnovers, where Chicago had 36 and then the next 11 teams were grouped between 26 and 31.

All of this is a long way to say that yes, the Bears’ 2019 defense is almost certainly not going to be as good as they were in 2018, but history suggests they are very likely still going to be one of the best defenses in the NFL. Which is good news when you consider that history also suggests Chicago’s offense is poised to be significantly better in 2019 than it was in 2018. I predicted after the Mack trade last fall that the Bears would have a top 5 unit on both sides of the ball in 2019, and I still believe that’s possible. My work this offseason has shown that both units are at least likely going to be top 10 if they follow historical trends.

[dll2000]

I think barring injury they are without question best D in NFL and I think they are a better unit than last year.

Whether that means they are statistically better, I don't know.  Probably not.

You can be better without having better stats.  A lot of other factors and variables involved.  Ball can bounce funny ways and opponents are different.  

Reasons I think they are better:

1) Roquan is a year older and will have a full camp.  He has a more aggressive coach which fits his strengths.  I think he has a break out year and improves over last year.

2) I do not think established stars of defense  - Eddie Jackson, Mack, Fuller, Goldman take a step back or will regress.  Mack I think is better with a full offseason and less worries about his situation.  Which is scary for the league.  

3) I think Nichols will be significantly improved this season and make more of a consistent impact.

4) I think HaHa C Dix is an underrated playmaker on ball that will thrive in this defense away from deep middle safety role to which he wasn't as well suited.  Especially without help around him.  

5) I think Trevathan is an excellent ILB that is a bit underrated and lost amongst all these great players.  

Reasons they may not perform as well as last year:

1) Injuries of course.  If Mack goes down the whole defense goes down a peg.  

2) Schedule and division is brutal.

3) I have a feeling PI calls will be kind of ridiculous this year with new emphasis and presence of challenges.  Prince and Skrine may struggle in that environment as they are handsy players.   Defense in general may become difficult to play with giant penalties for head hits, QB hits of any kind, illegal contact and PI penalties.  May set more scoring records this season.  The officiating may make an '85 type season despite the amazing assembled talent near impossible.

 

[soulman]

What could possibly change statistically is we give up even fewer points.

If Mitch and the offense can get untracked earlier and we begin playing with significant leads a more well rested and more aggressive pass defense could feast on QBs playing catch up.  That's what made the '85 defense so tough to beat.  If you had to pass they had you.

[beardown3231]

The way I look at is this: even if they aren't as good, and odds are they may suffer more injuries thus they might be worse, the offense will undoubtedly be better and it'll even out. I'm not all that concerned. Losing Hicks, Mack, Jackson, Fuller, Trubisky, Robinson, Leno or Cohen would be the 4 worst injuries on each side of the ball imo.

[dll2000]

1 hour ago, beardown3231 said:

The way I look at is this: even if they aren't as good, and odds are they may suffer more injuries thus they might be worse, the offense will undoubtedly be better and it'll even out. I'm not all that concerned. Losing Hicks, Mack, Jackson, Fuller, Trubisky, Robinson, Leno or Cohen would be the 4 worst injuries on each side of the ball imo.

I think we couldn't survive loss of Mack or MT.   We could survive obviously and win some games, but it takes us out of championship contention.  Daniel is a really smart guy, but simply isn't athletic enough to be a good NFL qb consistently.

We don't have another player who makes close to domino impact that Mack does at OLB.  His dominance effects everything else on the field.  You have to game plan for him.  Aside from Mack we have a hybrid in Floyd and a bunch of average to below average guys backing them up.  

Leno would be pretty bad too because of lack of quality experienced depth to replace him.

 

 

[dll2000]

21 hours ago, soulman said:

What could possibly change statistically is we give up even fewer points.

If Mitch and the offense can get untracked earlier and we begin playing with significant leads a more well rested and more aggressive pass defense could feast on QBs playing catch up.  That's what made the '85 defense so tough to beat.  If you had to pass they had you.

I think on paper taking opponents out of it, the defense is better for reasons already stated.

I think there is no question offense will be better.   Funny how the general national assumption is offense will be same or perhaps worse.

 

[dll2000]

The addition of Patterson, Davis and Montgomery is completely overlooked and discounted or seen as a lateral move or perhaps even a downgrade from Howard.

 

 

 

[dll2000]

Sowell and/or Shaheen might provide a TE RB blocking presence we lacked last year as well.

 

[soulman]

But as it relates to both the media and any preseason analysis no one can contemplate injuries in the mix so none of that is in the mix.

Those media types who want to insist the Bears will regress would have to do it on the basis of the team remaining reasonably healthy.

What would GB's chances be if Rodgers was lost during the opener?  Or Cousins in Minny or Stafford in Detroit.

What would happen to any NFCN defense if it lost one or two of it's top players?

IMHO the thinking about a defensive regression is based on two things; 1) the loss of Vic Fangio, and 2) we can't possibly create as many turnovers in 2019 as we did in 2018.

Neither is extremely valid but since when have some media type ever been required to validate their opinions in the same way a stats/metrics analyst like Jonathan Woods does?

And when proven wrong, as many were last season, which one then writes a mea culpa column confessing it?  Crickets........

Didn't think so.

[soulman]

5 hours ago, dll2000 said:

I think on paper taking opponents out of it, the defense is better for reasons already stated.

I think there is no question offense will be better.   Funny how the general national assumption is offense will be same or perhaps worse.

 

As I've posted.  In some quarters the Bears are still a very disliked team many hope will fail.

Those who do write columns predicting it.

It's whistling past the graveyard kind of wishful thinking.

Let's see how correct they are come January.

[dll2000]

I had to post this somewhere else defending Pagano:

Pagano has been coaching since 1984, probably before a lot of you were born,  and is a well regarded defensive mind by anyone who knows anything.

He is best known for coaching DBs.

Yeah, he was only a DC in NFL for one year, but he did so well he got a HC job immediately.  Indy had some good years under him, problems can come for any NFL team.   System is designed that way and he was dealing with possible death.  

I am sure you all would do great at your job if you started getting those symptoms and later got that diagnosis.

[soulman]

20 hours ago, dll2000 said:

I had to post this somewhere else defending Pagano:

Pagano has been coaching since 1984, probably before a lot of you were born,  and is a well regarded defensive mind by anyone who knows anything.

He is best known for coaching DBs.

Yeah, he was only a DC in NFL for one year, but he did so well he got a HC job immediately.  Indy had some good years under him, problems can come for any NFL team.   System is designed that way and he was dealing with possible death.  

I am sure you all would do great at your job if you started getting those symptoms and later got that diagnosis.

Has a kinda familiar ring to it doesn't it?

Nagy's inexperience even as an OC/Playcaller was given as a reason we'd be lucky to go 8-8 in 2018.

Nagy got guys to buy into his schemes and they played their ***** off for him and will continue to.

Pagano is getting similar feedback and treatment by his unit.  He's also very well respected and can handle his players.

[dll2000]

3 hours ago, soulman said:

Has a kinda familiar ring to it doesn't it?

Nagy's inexperience even as an OC/Playcaller was given as a reason we'd be lucky to go 8-8 in 2018.

Nagy got guys to buy into his schemes and they played their ***** off for him and will continue to.

Pagano is getting similar feedback and treatment by his unit.  He's also very well respected and can handle his players.

yes, I agree, but Pagano isn't young and inexperienced.

This guy has been coaching at a high level since 80s. 

He knows what he is doing.  He will be fine as a DC.  

Being a HC is whole other ball of wax and even then he was dealing with post Peyton rebuilding and then deadly cancer in short order.  He did good to start and all things considered. Team didn't draft well after Luck, in fact they drafted horribly.  Beyond horribly.  That isn't on Pagano.  

This guy is a good coach and Bears are lucky to have him.  

Media is being stupid or perhaps coy and duplicitous.  They are simply playing regression odds to look smart.  Hard to make a public case that Bears will be worse because of dumb luck, so they say it's because of DC change.

 

 

 

[soulman]

4 hours ago, dll2000 said:

yes, I agree, but Pagano isn't young and inexperienced.

I meant before he got the HC spot at Indy.  That was how I was comparing him to Nagy.  And that after only one year as a DC he got his captains wings.

My belief is that we could not have done any better than Pagano to replace Fangio and his staff.  Pagano will engender that same trust and respect because like Fangio he's been a successful DC and he's also been a successful HC.

[BEAR FACE DOWN ARROW]

I think you're right that he was best option

 

However I still got a really loser vibe from him in his hiring conference. My prediction is he gets with zero sacks and zero interceptions. Hope I'm wrong.