Charted NFL Waters: 2021 NFL Draft’s shallow defensive line class

Charted NFL Waters takes a closer look at the defensive lineman class in the 2021 NFL Draft, which appears to be the shallowest of all the position groups this year.

As we build up to the 2021 NFL Draft on Thursday night, it felt prudent to take a look at one of the classes that has been slightly overlooked this year, that of the interior defensive lineman.

Almost every single mock draft you look at will have Christian Barmore as the unanimous IDL1 and many will feature him as the only player at the position taken in the first round. The other name that is mentioned early is Levi Onwuzurike, a highly touted prospect from Washington who opted out last year.

I wanted to take a look at some of the other big names entering the draft this year to observe two things. 1. how can we effectively compare stats of all these players, and 2. Are there any guys from a statistical point of view that could be bargains when taken on Day 2 or even Day 3?

You can check out the full thread of my visualizations on Twitter.

To start, we have the 15 big names from the Power 5 conferences and their measurables. Two things stand out here. The first is weight. Compared to the NFL average for a defensive lineman, we have a huge number of guys that are considerably “underweight”.

This definitely isn’t a huge red flag, some of the best defensive linemen in the league are below the NFL average (Grady Jarrett clocks in at 290, Aaron Donald at 283). What Jarrett and Donald don’t have in weight, however, is outstanding technique and ridiculous strength.

Part of the lack of noise surrounding this IDL class is that no one has leaped off the page physically like Aaron Donald did in 2014 and that’s why there may still be questions whether the guys hovering around 280/290-pound mark can still pack a significant first punch to consistently get past offensive lineman.

The second aspect we notice is the opt-outs. Four opt-outs last year and this is significant because it means that those guys that didn’t play this year will be playing their first game in 19 months come Week 1 of preseason.

Unless you’re a freak athlete, like Penei Sewell or Ja’Marr Chase, it would be difficult for any team to pick up a guy early that they have no tape on after December 2019.

Looking at performance, I took four statistics from each IDLs most recent season: total pressures, sacks, defensive stops and tackles. To make these stats comparable, however, we have to adjust for strength of schedule.

For total pressures and sacks, which are pass rush statistics, I scaled each IDLs stats to a PFF pass-blocking grade of 50. For the defensive stops and tackles, we perform a similar transformation, but with the average of the PFF pass block and run block grade.

What exactly does this mean? Essentially, the purple bars give us the performance that each DL would be expected to have if they played against a pass-blocking unit and run blocking unit with a grade of 50. These figures are, therefore, adjusted for strength of schedule and can be compared.

On the pressures and sacks chart, Christian Barmore, Jaylen Twyman and Osa Odighizuwa dominate, whilst Barmore, Odighizuwa, Levi Onwuzurike and Daviyon Nixon look strong in the defensive stops and tackles figures.

It’s understandable from these charts why this is not a class that is being looked at too fondly. There appear to be slight issues somewhere with almost every prospect.

As expected, the numbers confirm our initial belief that Christian Barmore is the more rounded player in this draft class. Osa Odighizuwa also posts high numbers, but how significant is it that he only weighs 279 pounds? Levi Onwuzurike and Jaylen Twyman both look good but sat out last year and so may need longer than others to get back into a consistent rhythm. Daviyon Nixon dominated the run defense stats but appears to need a little bit more refinement in generating pressures and sacks.

It doesn’t look like there’s another guy that can compete with Barmore for the IDL1 spot, but it seems like there are a lot of guys here for which the long-term upside is very good. The teams that don’t need a starting defensive lineman and can afford to draft one of these guys and keep him at No. 2 on the depth chart could benefit hugely from a great talent for equally great value as they can pick up late.