Cowboys O-Line Continuity: When Too Many Personnel Changes Become A Bad Thing

Over the last couple of weeks, our own rabblerousr authored an excellent series of posts titled "Five Decisions That Shaped The Cowboys Season." In the final - and best, in my opinion - part of his five-part series, rabble looked at the "Offseason Injuries Along The Interior O-line" and argued that a series of injuries dating back to well before training camp robbed the Cowboys O-line of one of the most critical ingredients to O-line success: continuity.

The best offensive lines aren't necessarily those with the best athletes or most imposing specimens; rather, they are the ones that have played together long enough to develop a second sense about what their linemates are going to do. More than any other position, these guys play by "feel," especially when picking up stunts or passing a defensive lineman to the guy next to them. In short, continuity is key. Given the strategy to invest in low-round picks and have new offensive line coach Bill Callahan "coach 'em up," the only way to build a competent O-line was by developing that continuity.

Rabble went on to describe how the probable starting five (with Costa at center) only played a grand total of 126 snaps out of a possible 1,136 in 2012, and how the lack of continuity along the O-line wreaked havoc on the deep passing game the Cowboys traditionally favor. The Cowboys eventually adjusted by playing a higher percentage game that saw them grinding out a seemingly record number of first downs between weeks six and eleven before the O-line play finally improved.

In the season's final six weeks, Dallas totaled between 18 and 22 first downs. To my mind, this was largely the result of improved offensive line play; deep and medium-range passes returned to the Cowboys arsenal as Garrett was able to dial up calls that had heretofore been suicidally risky. The Cowboys' offensive line performed at season's end at a level that I figure they assumed they would to start the season--and that they'd grow from there.

Why am I reciting rabble's piece so extensively? Because I found the idea of O-line continuity highly intriguing. Not that O-line continuity is a novel concept of course, but I wondered whether there was a way to quantify what rabble had so eloquently described.

And wouldn't you know it, of course there's a way to quantify O-line continuity! Our good friends at Football Outsiders have developed a fairly straightforward metric they call the O-line Continuity Score. In their own words:

Continuity score starts with 48 and then subtracts:

* The number of players over five who started at least one game on the offensive line
* The number of times the team started at least one different lineman compared to the game before
* The difference between 16 and that team's longest streak where the same line started consecutive games.

Sounds complicated? It isn't. It is basically a number that measures the amount of change along an O-line over the course of a season. If you have the same five linemen starting all sixteen games, you get 48 points, and the more change you have along the line, the lower your score. FO explain the numbers as follows:

Continuity Scores above 41: Teams with excellent continuity average 1.87 points per drive and commit about 21 false starts in a season.

Continuity Scores 27-40: Teams with average continuity score 1.70 points per drive and commit about 23 false starts.

Continuity Scores below 26: Once teams start shuffling linemen, those values drop to 1.49 points and 26 false starts.

It's easy to confuse cause and effect in this situation -- poor play leads to personnel changes as much as personnel changes lead to poor play -- but the numbers suggest that teams should be wary of changing linemen just for change's sake.

FO have not published their official numbers for 2012 yet, so I went ahead and manually calculated the score for 2012. Applying FO's metric to the 2012 Cowboys gives us the following:

In addition to the five Week 1 starters (Smith, Livings, Costa, Bernadeau and Free), Cook, Dockery and Parnell started games for the Cowboys, so that lowers the score by three points from the initial 48. The starting line changed six times, which drops the score by another six points. The longest stretch the Cowboys played with the same line was a five-game stretch from Week 13 through Week 17, which further decreases the Continuity Score by eleven points. In total, the Cowboys' Continuity Score for 2012 is 28.

That's not a good place to be. Here's how the Cowboys' starting lineups along the O-line changed over the 2012 regular season, with most of the changes happening at center:

That's a lot of change in one season, and not exactly conducive for building continuity.

Apart from 2012, the Cowboys have done quite okay in this measure in the recent past. They finished in the top half of the league in four successive years from 2008 through 2011, but that changed in 2012. Here's the development over the last five years:

*Until FO publish their 2012 numbers, we won't know how that 28 Continuity Score ranks in the league, but between 2008 and 2011, 28 points were ranked 25th in the league on average.

The Continuity Score is fairly simple (but time consuming!) to calculate, so I added up the scores for all four NFC East teams in 2012, but didn't go further than that. Here's how those numbers compare:

• The Redskins came very close to a perfect score: Maurice Hurt replaced RT Tyler Polumbus in Week 16 for one start, but apart from that one change in one game, the line stayed the same throughout the season. That's the type of continuity you want to have, especially when you're starting a rookie quarterback. Yet that aspect of the Redskins game is often overlooked when talking about Bob Griffin's rookie season.
• The Giants are not far behind the Redskins. The Giants started the first two games with Sean Locklear playing left tackle in place of the injured Will Beatty, and David Diehl was in at right tackle. In Week 3, Beatty was back in at left tackle and Locklear moved to right tackle for Diehl. The line remained unchanged until Diehl came back and took the right tackle spot in week 15.
• The Eagles were hit by injuries to their O-line as well as a bad first-round draft pick, but when all is said and done, they had a league-average Continuity Score and their line played with fewer changes and more continuity than the Cowboys' line.
• The Cowboys had six different offensive lines starting in their first eleven games. It's hard to develop any type of continuity that way. But from Week 13 onward, the Cowboys started the same five guys for five consecutive games, and the performance of the line visibly improved.

The Cowboys entered the season expecting decent O-line play. Not great, not good, but okay. And the hope was that with some time together to develop continuity and with strong coaching, the unit could perhaps turn into a good line. But offseason and training camp injuries led to a lack of continuity that threw the entire line out of whack so badly that the Cowboys had to significantly alter their gameplans to account for the O-line's struggles for large parts of the season.

The line eventually overcame those issues, and played decently at the end of the season. Which leaves the Cowboys in a bit of a conundrum. If the bad line play was the result of poor individual play, then you'll probably have to bring in players with better individual skills. But if the bad line play was the result of constant personnel changes, then new personnel may not be the answer. Unfortunately, there is no way to plan for O-line continuity.

It's still too early to say who the starters on the Cowboys' offensive line will be this year. But it's fairly certain that the line will look different from last year's line. As it should. But when does too much of a good thing - in this case: change on the offensive line - become a bad thing?

A while back, the Patriots' Matt Light remarked on the benefits of continuity along the offensive line:

"The obvious part is the familiarity," Light said. "It's not impossible, but it's a heck of a learning curve trying to get used to playing next to another guy and all the mistakes that come with that. When you've been able to keep a group together, you are able to get through camp so much easier. You're able to install things quicker."

The data above shows that the lack of continuity may have had a lot more to do with the O-line's performance in 2012 than is widely acknowledged, and if nothing else, it provides some additional food for thought as we contemplate what the best strategy is for the Cowboys to win more games in 2013.