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The Seahawks offensive line: Improvement through experience

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Part II: Evaluating the improvement of offensive linemen over time.

NFL: Seattle Seahawks at Los Angeles Chargers
Justin Britt: Much improved since arriving in the NFL
Jake Roth-USA TODAY Sports

In Part I of this series (Tom Cable may be doing a better job than you think), I looked at how the offensive linemen drafted by the Seattle Seahawks have performed relative to their draft position, and as pointed out in the article -- and in the comments many times over -- AV is a very imprecise tool. It’s kind of like a home security system that does nothing more than transmit aerial photographs of your home from 30,000 feet; Maybe that’s your house on fire down there, maybe it’s neighbors; Maybe you’re looking at the wrong town, you can’t really tell for certain with what you’ve been given.

As with any data on offensive linemen, AV is imprecise and can be interpreted differently. Agree or disagree with the method, you have to make use of the tools you have at your disposal, and unfortunately there isn’t a lot out there for offensive linemen.

Part II: Improvement of Offensive Linemen Over Time

That’s why I set out on a ridiculously more time consuming project than I had initially thought I was jumping into a few months back when I began looking into the development of offensive linemen over seasons. Now, as just mentioned, there aren’t a whole lot of data sets out there to analyze the performance of offensive linemen over time. So, I set out to take a look at the data that is available to see what I could make of it. Thus, I put together a spreadsheet of every offensive lineman in the NFL drafted in the first four rounds between 2012 and 2016 and then looked at the snap counts by season for each and every one of the 124 offensive linemen drafted during that timeframe. To things one step further I then pulled the data for sacks allowed for each of these 124 offensive linemen for each season they have been in the league.

Now, I’ll be the very first to admit that the usefulness of this data is once again limited for several reasons I will delve into later, but once again, we have to make due with what we have available.

(If anyone is aware of a better source of data for evaluating offensive linemen, please leave a note in the comments and I will more than happily dive into it and see how it can be used.)

Once I had this giant spreadsheet of snaps and sacks I went about trying to determine how I could put this to use in evaluating the Seahawks offensive linemen. For starters, I was hoping to develop a baseline for the improvement of offensive linemen over time, so the first thing I did was evaluate the number of snaps played and sacks allowed for all the offensive linemen in the data set based on their year of play in the league.

Basically, I added all the snaps played as rookies by each of the individual draft classes in their respective years together, and then did the same for their second, third and fourth years for as long as I had data (obviously, only the 2012 and 2013 classes have four years of data). Then I did the same thing for sacks allowed based on year in the league. That gave me a bunch of huge numbers that really meant nothing, so in the end I divided the sacks allowed by the snaps played and then multiplied the result by a thousand in order to yield a normalized result that would represent the number of sacks allowed over the course of 1,000 snaps, which also happens to be roughly the number of snaps an offense plays over the course of a season.

The results are as follows:

Improvement over time for offensive linemen

Season Sacks Allowed per 1000 Snaps
Season Sacks Allowed per 1000 Snaps
First Year 4.69
Second Year 4.32
Third Year 3.89
Fourth Year 3.37
Data based on every offensive lineman drafted in the first four rounds between 2012 and 2015.

That seems to show some improvement over time, but a significant portion of the improvement was due to survivorship bias, as the linemen who didn’t improve did not get to continue to play for very long. Guys like Cyrus Kouandjio and Jonathon Martin helped lift the number of sacks allowed in the early years of data, but didn’t get that same opportunity in the later years.

In any case, what the data did routinely show was significant improvement for offensive linemen over the course of playing multiple seasons. I’m not going to bury you readers with the full 124 lines of data, but I’ve pulled out some names that should be familiar to many that illustrate the kind of improvement that linemen see as they go from being rookies to being seasoned veterans.

(Author’s Note: I have this data for every offensive lineman drafted from 2012 through 2016, so if there is anyone in that group you would like to see the data for, leave a note in the comments and when I have a chance I can post it in a response.)

Skill Progression for Selected Offensive Linemen

Year Rnd Pick Player 2012 Sacks per 1000 Snaps 2013 Sacks per 1000 snaps 2014 Sacks per 1000 Snaps 2015 Sacks per 1000 Snaps 2016 Snaps per 1000 Snaps
Year Rnd Pick Player 2012 Sacks per 1000 Snaps 2013 Sacks per 1000 snaps 2014 Sacks per 1000 Snaps 2015 Sacks per 1000 Snaps 2016 Snaps per 1000 Snaps
2014 1 6 Jake Matthews N/A N/A 7.42 3.11 5.11
2014 1 11 Taylor Lewan N/A N/A 11.3 7.16 1.01
2014 1 16 Zack Martin N/A N/A 1.9 1.94 1.89
2014 2 35 Joel Bitonio N/A N/A 1.43 4.88 3.02
2014 2 59 Jack Mewhort N/A N/A 2.53 0.46 0
2014 2 64 Justin Britt N/A N/A 7.09 2.32 0
2014 3 81 Gabe Jackson N/A N/A 1.85 2.37 0
2014 3 93 Brandon Linder N/A N/A 6.66 0 2.2
2013 1 2 Luke Joeckel N/A 12.87 8.66 8.33 0
2013 1 4 Lane Johnson N/A 7.71 2.81 4.76 0
2013 1 10 Chance Warmack N/A 6.05 3.11 3.61 7.46
2013 1 11 D.J. Fluker N/A 5.74 5.88 1.16 4.04
2013 1 31 Travis Frederick N/A 3.51 0.47 0 0
2013 2 42 Menelik Watson N/A 5.78 8.23 N/A 3.92
2013 3 65 Larry Warford N/A 0 4.46 3.07 3.09
2013 3 75 Terron Armstead N/A 21.9 3.59 3.23 2.51
2012 1 4 Matt Kalil 5.31 5.28 13.43 5.43 12.4
2012 1 23 Riley Reiff 0 6..34 3.19 4.19 4.5
2012 1 24 David DeCastro 18.38 1.32 1.8 1.4 1.85
2012 1 27 Kevin Zeitler 4.28 1.55 3.39 1.92 0.92
2012 2 60 Kelechi Osemele 7.87 2.36 3.21 2.56 0
It took a ton of time to gather the data to put into this little spreadsheet.

Obviously, this methodology leaves a lot to be desired because there are so many factors that go into play that are imprecise. Just a few of these are that the sacks allowed numbers are being assigned by outside observers who have no idea which lineman missed an assignment, different teams maintain different run:pass ratios and it takes into account all snaps, not just passing snaps. Once again, however, you’ve got to use the tools available. In addition, the sole point of this is simply to demonstrate that many offensive linemen do in fact improve as they gain experience at the NFL level. The numbers show this, and that even when someone like Kevin Zeitler comes into the league performing at a high level, they can continue to improve. Time and again the numbers show a sudden improvement for a player two or three years into their career, and it’s as if overnight they are good at what they do.

It is this which gives me hope for the Hawks offensive line, given the youth and relative lack of experience of the current Hawks line, and those are subjects I will touch on in Part III.