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How Has The Cowboys' Young O-Line Held Up In Run Blocking So Far?

Four weeks into the new season, you don't need a calculator or fancy spreadsheet to tell you that the Cowboys running game is not yet firing on all cylinders. The Cowboys have (barely) surpassed 100 yards rushing only twice in four games. They rank a joint 25th in total rushing yards through four games and have averaged only 3.4 yards per carry.

Evaluating the O-line's role in this is not easy. There was a time not so long ago where an offensive line's performance was only measured by what didn't happen: the quarterback was not sacked and the running back was not stuffed in the backfield. Today, there are more statistics available to help evaluate an offensive line. Perennial BTB favorite Brian Burke of uses Winning Probability Added Win (measures each play in terms of how much it increased or decreased a team’s chances of winning the game) and ranks the Cowboys O-line 26th. Stats Inc. have hustled New York Life into sponsoring a super duper top-secret formula which has the Cowboys ranked 6th but provides no explanation for that at all. And another favorite of ours, Football Outsiders (FO), also ranks the Cowboys O-line 25th in run blocking and 6th in pass protection.

After the break, we take a closer look at couple of advanced metrics from FO – Line Yards, Power Success, Open Field Yards and Stuffs - to see how the Cowboys offensive line has fared in run blocking so far this year.

Last week we looked at how the O-line held up in pass protection, and found that the young O-line performed better than expected. Today we focus on run blocking with the help of Football Outsiders. FO have developed their own specific metrics and terminology, and I'll highlight them briefly as we look at each stat category below.

Adjusted Line Yards:

Based on regression analysis, the Adjusted Line Yards (ALY) formula takes all running back carries and assigns responsibility to the offensive line based on the following percentages:

Losses: 120% value
0-4 Yards: 100% value
5-10 Yards: 50% value
11+ Yards: 0% value

These numbers are then adjusted based on down, distance, situation, opponent, and the difference in rushing average between shotgun compared to standard formations. Finally, we normalize the numbers so that the league average for Adjusted Line Yards per carry is the same as the league average for RB yards per carry [which is 4.23 yards after four weeks so far].

What this metric does is it penalizes an offensive line when a runner is tackled for a loss by adding 20% on top of the negative yardage (e.g. a run for -5 yards is credited with -6 yards, or 120% of the original value). Also, the metric gives progressively less credit for long runs: The first four yards of a run are fully credited, the next six yards (the running back hits the second level between 5 and 10 yards out) are only credited with half the actual yardage, for all yardage beyond the 10 yard line (the running back is now in the open field) the offensive line doesn’t get any credit whatsoever. Using Adjusted Line Yards, this is how the Cowboys offensive line performed so far this year, and how that compares to previous years:

Rank Adj. Line Yards RB Yards NFL Avg
2009 3 4.47 4.99 4.29
2010 12 4.12 3.87 4.19
Wk 4, 2011 25 3.72 3.62 4.23

On average, the Cowboys' offensive line cleared the path for only 3.72 yards per run for the running backs, which is about half a yard below the NFL average. That has got to be disappointing, and is an early indication that the O-line is at least partly to blame for the underperforming running game.

The running backs

Obviously, the backs and the line have a symbiotic relationship and it's hard to evaluate one without the other. So while you can't completely separate the effect the two position groups have on each other, you can approximate it by looking at the relationship between Adjusted Line Yards and Running Back Yards. FO define running back yards as follows:

Yards per carry by that team's running backs, according to standard NFL numbers.

Per the table above, the Cowboys’ running backs gained 3.62 yards in running back yards in 2010, ranked 27th in the league. That's a further drop from the 25th ranked 2010 unit. Not good by any measure.

If you deduct the the Adjusted Line Yards from the Running Back Yards you'll get a good measure of how the running backs performed relative to the line, because by taking away the contribution of the offensive line, be it good or bad, you'll get a measure of how good a running game a team has. The Cowboys running backs are -0.1 in this measure. And this is where you could start to get a little nervous.

We knew that the line would struggle this season. Two rookies without the benefit of a full NFL strength and conditioning program can get pushed around on occasion. But it's not like other teams don't struggle with their lines in run-blocking.

Take the Bears for example. In terms of adjusted line yards (ALY), their line is even worse than the Cowboys' line. The Bears average only 3.53 ALY and are ranked 28th. Yet their running backs are putting up 4.79 running back yards. The Bears have a different issue altogether in that they simply haven't run enough in the first four weeks, but when they did run, they ran very well. It's a similar situation in Atlanta: 3.57 ALY, ranked 27th, but with 4.33 running back yards. The Cowboys will have to look hard at their running game, and while it may be convenient to blame the line for the disappointing run game, the stats point more in the direction of the running backs.

So let's use another FO metric for running backs, DVOA or Defense-adjusted Value Over Average. DVOA breaks down every single play of the NFL season to see how much success offensive players achieved in each specific situation compared to the league average in that situation, adjusted for the strength of the opponent.

Player '09 DVOA '10 DVOA Player '11 DVOA
Felix Jones 8.9% (15th) 8.2% (10th) Felix Jones -21.8% (32nd)
Marion Barber 17.0% (5th) -12.3% (36th) DeMarco Murray -13.6% (- -)
Tashard Choice 24.7% (- -) -4.8% (- -)
Tashard Choice -32.0% (- -)

It's still early in 2011, but none of the running backs can be happy with their performance so far. Choice and Murray are not ranked because they do not have the minimum qualifying number of carries to make the top list.

The Cowboys famously have only had two runs of 20+ yards. Might that be screwing with the numbers, especially this early in the season? On to the next set of metrics.

Power Success

Percentage of runs on third or fourth down, two yards or less to go, that achieved a first down or touchdown. Also includes runs on first-and-goal or second-and-goal from the two-yard line or closer.

The Cowboys' short yardage woes are well documented and reach back at least two years, in which they've continuously struggled in short yardage situations, especially in goal line situations. But if anything, that got even worse this year, as the numbers below show:

Rank Power Success NFL Avg
2009 26 58% 64%
2010 26 54% 62%
wk 4 2011 31 38% 62%

The Cowboys are getting hardly any push on the line. Heck, they've even brought in NT Josh Brent as a fullback on three snaps to provide some more push. To no avail. The short game is and remains the Achilles heel of the Cowboys offense. More often than not, our linemen simply cannot get enough push to clear the necessary yardage for the RBs. Of course, it doesn't help if our running backs plow straight into the pile in the first place.

10+ Yards or Open Field Yards

Yardage gained by running backs at least 10 yards past the line of scrimmage, divided by total running back carries.

FO are calling all yardage beyond ten yards ‘Open Field Yards’. If you take Open Field Yards divided by total carries, you get an indicator for ‘big play ability’, or at least ‘break away ability’ of your running game.

Open Field Yards
Rank 10+ Yard runs / carries NFL Avg
2009 5 1.16 0.82
2010 26 0.49 0.70
wk 4 2011
19 0.67 0.71

Most breakaway runs usually happen when a running back scoots through a hole the offensive linemen opened. If your backs are unable to get down the field with any regularity, chances are it’s the offensive linemen that are not making it happen. The 2011 Cowboys are close to average in this metric, an indication that the line is able to open holes for the backs, at least occasionally.


The Cowboys running game was stuffed at or behind the line of scrimmage on 18% of all runs, which ranks the Cowboys 14th in the league.


The Cowboys' young O-line still has a long way to go in run blocking. The key issue appears to be their inability to get enough push off the line, which is especially obvious in short yardage situations. This may be due to the lack of strength, lack of technique or simple lack of mass along a line that is manned by two rookies and one first-year player. But what is disconcerting is that the Cowboys have had the same problems in short yardage situations with an entirely different cast of linemen over the last few years. 

And the Cowboys running backs haven't exactly excelled either. Backs on other teams with similar issues along the line have performed much better.

Finally, keep in mind that these are only the results of four weeks. The Cowboys may have simply gotten off to a slow start. We still don't know just how good the defenses were that the Cowboys have played so far and for what it's worth, the Cowboys running game seems to be on an upward trend. There are many other reasons that could also apply, but the Cowboys have to get better in this area, and they still have 12 weeks to improve. The only way is up.

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