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Don’t Blame Defense for Offensive Regression

| January 13th, 2020

Chicago scored only 17.5 points per game in 2018, the 4th worst mark in the NFL. This was a significant drop from 2018, when they were 9th best in the NFL at 26.3 points per game. I’ve seen some people argue that this is mainly due to Chicago’s defense, which scored 5 fewer touchdowns and forced 17 fewer turnovers in 2019. The logic then was that the offense in 2018 was just as bad, but it was overshadowed by a dominant defense that handed them points on a regular basis.

This argument made me curious, so I dug into the numbers to see if it held up.


Non-Offensive Points

The 2018 Bears had 44 points that were scored by their defense and special teams, while the 2019 version had 16*. If you remove those from the season totals, the 2018 offense scored 277 points (23.6 per game) while the 2019 version scored 264 (16.5 per game).

That means Chicago’s offense scored 7.1 points per game more in 2018 than 2019. The total points scored dropped by 8.8 per game, so clearly the bulk of that was from offensive points, not defense/special teams.

*Quick disclaimer: I tallied touchdowns, field goals and safeties, and applied values of 7, 3, and 2, respectively, for each. These numbers might be a little off because not all touchdowns result in exactly 7 points due to missed extra points or going for 2.


Points Off Turnovers

Of course, points directly scored by the defense is only half of the original argument. The 2018 defense also forced far more turnovers, in theory setting the offense up in better field position for more easy points. In order to see what effect this had, I looked at points scored off turnovers for each team using Pro Football Reference’s Drive Finder. The table below shows the data.

Despite forcing far more turnovers, the Bears didn’t actually get many more points from them. Part of this may because of where the turnovers happened; the average starting field position for these drives was the Chicago 42 in 2018 and the opponent 47 in 2019. Accordingly, the Bears got 2.4 points per drive off turnovers in 2018 and 3.3 in 2019. Because of this, offensive scoring following a defensive turnover changed by only 0.7 points per game from 2018 to 2019.

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Data Entry: Turning Over the Turnover Problem

| March 13th, 2017

This is the 3rd installment of a monthly offseason piece I’ll be doing here at DaBearsBlog, helping fill the content void of the long offseason. Each one will be a numbers-crunching look at something Bears related in which I attempt to earn the “Data” moniker so kindly bestowed on me by the comments section regulars and, more importantly, answer a Bears question that I’ve been wondering about. If you have anything you’d like me to look into, let me know in the comments or email me at woodjohnathan1@gmail.com and I’ll see what I can do.


Chicago’s defense has significantly improved in the last two years from the disaster that was the Mel Tucker era, but there is one area where they have actually regressed: forcing turnovers.

Tucker’s defenses in 2013 and 2014 actually forced turnovers at a slightly-above average rate (Tucker can probably thank the leftover Lovie Smith-trained players for that), while Vic Fangio’s defenses have forced fewer turnovers in the last 2 years than any other NFL defense. In fact, 13 defenses have forced as many turnovers in one season (28) as the Bears’ defense has the last two seasons combined.

The problem was particularly pronounced last year, when the Bears forced a measly 11 turnovers, tied for the fewest by any defense in the NFL in the last 10 years.

Given the strong and well-established relationship between winning the turnover battle and winning football games, this is a real problem for Chicago. All of this research looks at turnover differential, not just turnovers forced. But forcing turnovers is half of turnover differential and it’s the part I want to focus on today. Avoiding turnovers is largely a product of your quarterback (and luck for fumbles/fumble recoveries). That’s a separate issue that has already been discussed on here at length.

Setting it up

Here’s my question: What is the history for teams the year after they have forced as few turnovers as the Bears have recently? Does the defense continue to struggle generating turnovers, or does it improve quickly?

Here’s how I approached the study:

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