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Understanding the Role of Newly-Acquired Free Agents in 2019: Defense

| March 21st, 2019

The Bears have made a number of moves in free agency, and I want to use some advanced statistics to weigh in on their likely role on the roster and value to the team. We looked at the offense yesterday, and now will move to the defense, where the Bears will be replacing two starters.

Buster Skrine

Nickelback Bryce Callahan followed Vic Fangio to the Broncos, and the Bears replaced him with Buster Skrine, who was a bit cheaper ($5.5 million/year vs. $7 million/year) and has been a bit healthier (5 games missed vs. 12 games missed in last 3 years). According to The Quant Edge, both players have spent the majority of their time over the last three years at nickel, though Skrine has spent a bit more (roughly 30%, compared to 15%) playing outside.

The table below uses data from The Quant Edge to show how effective each player has been in coverage. In order to increase sample sizes, I looked at Skrine and Callahan cumulatively from 2016-18 (I’ll note this actually helped Callahan and hurt Skrine, lest I be accused of trying to skew the numbers in the Bears’ favor), and for context compared them to averaged 2018 stats from five other nickelbacks who are widely viewed as being quality players: Chris Harris, Aaron Colvin, Tavon Young, Nickell Robey-Coleman, and Justin Coleman.

Based on this data, it is pretty clear to see that Skrine is a downgrade from Callahan, but that is not to say he’s a bad player. Skrine gets targeted more frequently than other nickel CBs, but holds up to the targeting quite well. The only thing that really jumps out poorly there is the TD:INT ratio. Like Callahan, Skrine doesn’t really get many interceptions, and he has given up more scores than you would like to see.

Of course, these stats for Skrine were all playing on the Jets, who have ranked in the bottom 10 in points allowed each of the last 3 years. It is possible that Skrine will perform better in a better situation in Chicago. And don’t overlook the difference in availability either. Skrine has played about 2400 snaps over the last 3 years compared to 1600 for Callahan. As we saw in 2018, Callahan can’t help you in the playoffs if he’s not healthy.

If you want to see a good film breakdown of Skrine’s pros and cons, Robert Schmitz of Windy City Gridiron has you covered.

One final note: while Skrine has been healthier than Callahan, he does have a concussion history that is a bit troubling. He suffered three concussions between 2016 and 2017, and he had another in 2018. Here’s hoping that doesn’t become an issue in Chicago too, as concussion problems can really snowball once they start.


HaHa Clinton-Dix

And now we end with safety, where the Bears lost Adrian Amos to the Packers and replaced him with former GB safety HaHa Clinton-Dix.

I don’t really have many stats to present here, because in my opinion advanced statistics don’t really evaluate safety play very effectively. If you look at coverage stats for Adrian Amos and Eddie Jackson in 2018, you’d come to the conclusion that Adrian Amos is a better player – he was targeted less often and gave up fewer yards/target and a lower passer rating on passes targeted to him – and there is simply no way you will ever convince me that is anywhere close to true. My belief is that a lot of what safeties provide in coverage doesn’t directly show up in their stats, since they are often giving support to cornerbacks and not the direct target of passes they have a chance to make a play on. Safety roles also vary tremendously, so it’s difficult to compare coverage stats for players like Eddie Jackson and Adrian Amos because Jackson is asked to do so much more.

So with that said, I’m not going to try to argue who out of Amos and Clinton-Dix are better, because I honestly don’t know. Having watched the Bears closely in Amos’ four years here, I can tell you exactly what he provides: he’s a solid, reliable safety who does his job well and doesn’t give up big plays, but he also is not a playmaker. That has value, but the Bears simply couldn’t afford to pay him $9 million a year to be one of their worst defenders (this is not a knock on Amos, but more a testament to how good the rest of their defense is). Paying that position $3.5 million – the amount they paid Clinton-Dix – is a lot more manageable.

I do have a few basic stats to compare between the two players, focusing on the last 3 years, when they were both firmly established as starters and not learning the ropes as rookies.

  • Games missed: 0 for Clinton-Dix, 4 for Amos
  • Tackles: 251 (202 solo) for Clinton-Dix, 206 (173 solo) for Amos
  • Missed tackles: 21 for Clinton-Dix, 25 for Amos (per Pro Football Focus)
  • Interceptions: 11 for Clinton-Dix, 3 for Amos

Again, these statistics aren’t to say that Clinton-Dix is better than Amos. Safety play is really difficult to quantify with statistics. I just don’t think there’s a statistical argument to be made that Clinton-Dix is any worse, and he’s less than half of the price. Clinton-Dix is consistently available, doesn’t miss a lot of tackles, and certainly makes more big plays than Amos does. He said he took less money to try and win a ring with Chicago, so Bears fans should be grateful they got a quality player for so cheap.

If you’re curious for more of an Xs and Os breakdown of what Clinton-Dix does and doesn’t do well, then you should check out this great film thread by Brandon Robinson.

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