One of the most interesting coaching positions in sports is the offensive line coach. While the NFL has rallied around rules that have exploded passing efficiency since 2004, there is still little to no movement for the coaches who have hands-on roles with what amounts to half of a team's starters on the offensive side of the ball. Offensive coordinators are largely made up of former quarterbacks coaches. It seems like every year more of the NFL's head coaching positions are filled by former offensive coordinators...who were former quarterbacks coaches.

This leaves offensive line coaches in a weird spot. They are in charge of half of the offense. They coach the most expensive non-quarterbacks on the offense. Meanwhile, the linear path from quarterbacks coach to offensive coordinator to head coach keeps everyone else in pretty stagnant positions. The difference? Other positional coaches do not coach half of a team on the field.

Something I have always wondered was how much an offensive line coach like Dante Scarnecchia, who first took over as New England's offensive line coach from 1999 to 2013 and came back for a second stint starting in 2016, really mattered in the context of the Bill Belichick era. Is he third most valuable guy behind Belichick and Tom Brady? It is hard to root that in something tangible when individual stats for offensive linemen are not tracked on a league page. People talk about offensive line coaches mattering, more so than other positional coaches at the NFL level, but I have never seen it quantified before.

In an attempt to do so, I tracked every current NFL offensive line coach's resume dating back to 2004, when we entered a pass-friendly era. What I tracked was two things: Sack Value and TFL Value for individual teams in individual seasons.

Sack Value: (((Team sacks given up/Team total pass plays)-(NFL sacks given up/NFL total pass plays))*Team total pass plays)*-1

TFL Value: (((Team tackles for a loss given up/Team total run plays)-(NFL total tackles for a loss given up/NFL total run plays))*Team total run plays)*-1

I treated tackles at the line as tackles for a loss with the idea being that if a back did not get momentum to push even a yard, there was likely to be penetration caused by an offensive lineman. I also excluded kneel downs from the data sample.

If there are any easy counting stats that could be attributed (and easily accessed) to the performance of offensive linemen, it would be sacks and TFLs. The value system adjusts for what the NFL average in the stat was in a given year, giving it an era adjustment for rule changes, and attributes a plus-minus number that is tangible.

Examples: +5 Sack Value means a team prevented five sacks better than the NFL average. -3 TFL Value means a team allowed three TFLs worse than the NFL average.

From there, you match current offensive line coaches to teams which they had qualifying coaching roles for (offensive line coach, offensive coordinator and head coach) and BOOM you find the value of offensive lines while these coaches have been in roles to heavily-influence them. From there, we can try to answer questions like "How good is Dante Scarnecchia?"

Results:

These are the numbers updated through Week 14 of the 2018 NFL season. As you can see, Scarnecchia really does matter more than any other offensive line coach in the NFL. His offensive linemen have collectively taken away 111 sacks relative to the NFL average, about as good as a Hall of Fame pass-rusher, and he ranks first in the NFL among offensive line coaches with a +121 TFL Value.

Behind Scarnecchia are three other offensive line coaches who have separated themselves from the pack: Dan Roushar of New Orleans, Mike Munchak of Pittsburgh and Bill Callahan of Washington. Munchak and Callahan are long-time NFL coaches who even earned head coaching jobs in the past while Roushar, ranked third on the list, has only been an NFL offensive line coach for three seasons. If there is anyone tabbed to be "The Next Scarnecchia" it is Roushar.

Some coaches, like Kansas City's Andy Heck, Houston's Mike Devlin, Carolina's John Matsko and Oakland's Tom Cable, are historically good in TFL Value but historically poor in Sack Value. Others, like Munchak and the Chargers' Pat Meyer, are historically good in Sack Value but historically poor in TFL Value.

In terms of career resumes, at least from 2004 on, the three most costly current offensive line coaches are Cable, Tampa Bay's George Warhop and Detroit's Jeff Davidson...and by a pretty good margin. What is interesting is that Mike Solari, who has really turned around the Seahawks' offensive line, ranks 31st out of 34 offensive line coaches in career resume. The difference? Cable is more than twice as costly.

As we approach hire-fire season, keep this list of names in mind. Davidson is coming to town? Add some more sacks to the total. Need a head coach? Roushar might be a sneaky candidate to get a look based off of what Munchak and Callahan have done to get head jobs.