Football Outsiders Q&A, Part 3: On Packers RBs’ receiving stats & new key defenders

n 2020, SB Nation and Football Outsiders have partnered once again to take a deep dive into the analytics and numbers of football. This year, Bryan Knowles from FO answered a series of questions from Acme Packing Company about the Green Bay Packers with a stat-heavy focus.

Check out their work at FootballOutsiders.com, where the 2020 Football Outsiders Almanac is now available.

Last week, we discussed a few interesting topics in our Q&A with Football Outsiders’ Bryan Knowles, touching on arguably the two biggest playmakers on the Green Bay Packers’ offense. Today we will wrap up our Q&A with a grab bag of questions, one on another set of playmakers on that side of the football and two discussing defensive contributors who are either new to the Packers or new to their expected roles in 2020.

Without further ado, here are those exchanges. Thanks as always to the FO team and to Bryan Knowles in particular for answering our questions.

Acme Packing Company: Aaron Jones and Jamaal Williams both seem to be relatively effective receiving backs, but Williams’ DVOA was a whopping +27.4% compared to Jones -5.1% despite Jones having a much better yards per target and per catch average. Was this largely due to Williams’ five touchdown catches, a difference in catch rate (87% to Jones’ 72%), or something else?

Not all yards are created equal! The missing variables here are success rate and failed completions. A five-yard reception on 3rd-and-10 is a negative play; a five-yard reception on 3rd-and-4 is a positive one. Aaron Jones was targeted 68 times, and only 30 of them ended up as successful plays — plays which pick up 45% of the yards to go on first down, 60% on second down, or 100% on third and fourth down. That’s a success rate of 44%. Jamaal Williams, on the other hand, had 45 targets and 24 successes, or a 53% success rate. Jones had more negative plays than Williams did, in other words, but that’s more a matter of usage than of skill — Jones isn’t the one calling for screens on 3rd-and-18 or 3rd-and-27, and it’s probably unfair to expect him to convert those. If it wasn’t for Jones’ one fumble, he’d have a better DVOA than Williams on both successful targets and unsuccessful targets; he just suffered from a higher rate of those incompletions and failed completions than Williams.

This is interesting; it actually sounds like how Jones is used as a receiver hurts him here. Splitting him out wide and sending him deep naturally will lead to more incompletions, whereas Williams seems to be almost exclusively a dump-off, safety-valve option whose receptions come in high-probability scenarios where he can pick up useful yardage. It’s something we noticed a few weeks ago: Jones’ average depth of target was 2.7 yards past the line of scrimmage, while Williams’ was 0.8 yards behind the line. And Jones is a better threat to actually make people miss once he does get the ball as well, averaging more than a yard over expected after the catch while Williams was 0.3 yards below expected.

This is a reminder — to this writer in particular — that scheme and usage play a significant role in DVOA, and combined with Adams’ numbers it helps underscore that it is not necessarily a reflection on talent, just on results.

APC: He doesn’t have a ton of snaps to project from, but Chandon Sullivan appears set to take over from Tramon Williams as the Packers’ nickel cornerback. His success rate and passer rating against numbers look great in that small sample size, though — do you see enough there to justify the Packers keeping him over the aging Williams?

I like the gamble of Sullivan over Williams. Williams can’t have much left in the tank at age 37, though he was still a good player a year ago. You’re right in that Sullivan only has a small sample size to work from, but a 76% success rate last season isn’t anything to scoff at — that was the best for any player with at least 20 targets last season. There’s always worries about the transition from special teamer and depth corner to starter, but there’s been nothing to dislike about Sullivan’s game to this point. Roll the dice with the younger (and cheaper!) option!

Sullivan is a top performer in another stat? We already knew that he led the team in passer rating allowed into his coverage; this seems like another stellar number to point to as why the Packers are confident in him taking over in the slot this fall.

APC: The one major turnover spot on defense comes at linebacker with Christian Kirksey taking over for Blake Martinez, who notably said in his first press conference with the Giants that he was just the “clean-up guy” for Mike Pettine. Does Kirksey seem to bring more coverage ability than Martinez, or does he project to a similar run-focused role that Martinez played in 2019?

What the Packers will get out of Kirksey is anyone’s guess; he hasn’t managed a full season since 2017. When it comes to coverage, however, even a fully healthy Kirksey was never great shakes — he had a 47% success rate in 2017 and a 33% success rate in 2018. That still compares favorably to Martinez’s 38% success rate from last year, and early reports from training camp have been positive, but it’s not his primary selling point. I’d expect him to be primarily a run-thumper, and for the Packers to once again lead the league in dime packages this year.

This isn’t exactly a thrilling analysis of Kirksey, particularly since the team appears convinced that he’s going to be a significantly better coverage linebacker than Martinez was. We’ll have to see if that confidence bears out; if it does, perhaps that will indeed mean more Kamal Martin or Oren Burks at the Will spot next to him, but if not, Raven Greene may be in for a big role as a dime linebacker once again.