Adjusting Yards-Per-Carry based on Defensive Personnel Packages

During the 2012 season, Saints’ starting tailback Mark Ingram averaged 3.9 yards-per-carry. That’s not very good

Fellow Saints running back Darren Sproles averaged 5.2 yards-per-carry. That is very good.

Ingram carried the ball 156 times out of the backfield, compared to only 47 for Sproles.

On the surface, it appears that the carry split between the two backs should be reversed. The problem with a quick jump to that conclusion, however, is the fact that the two backs played very different roles.

Ingram, the team’s early-down and short-yardage back, faced a defensive personnel package that included five-plus defensive backs on 13 (or 8 percent) of his 156 carries. Sproles, meanwhile, saw five-plus defensive backs on 44 (or 94 percent) of his 47 carries.

All of a sudden, unadjusted YPC no longer feels like a fair indicator of actual production.

Today, I’m taking steps towards adjusting YPC so that we’re left with a more accurate assessment of each player.

The best method I could think of in order to achieve this goal was to weight each carry based on a predetermined expected YPC vs. each type of defensive package.

To do this, I first went back five years, splitting every designed run out of the backfield into nine defensive back-based categories.

Here is what I came up with:

The first column indicates the number of defensive backs on the field. The ‘n’ is simply there to indicate that all carries aren’t included. Scrambles, sneaks, kneels, and reverses are removed.

In what shouldn’t even be a little bit surprising, YPC goes up as the number of defensive backs on the field rises.

I compared all 65,291 designed runs to the above chart, which gave me adjusted and expected YPC marks for each player.

Of 76 running backs with 45-plus qualified carries in 2012, Sproles benefited most from the defensive personnel he faced. Our test drops his YPC from 5.2 to 4.3. His expected YPC (a calculation that determines the YPC an average NFL back would put up against the same personal package split) is 5.4.

Ingram, meanwhile, was the 13^th “unluckiest” back related to opposing personnel. He only jumps up to 4.0 from 3.9, however. The reason is the fact that he only managed a 3.9 YPC on 134 carries against base packages. This is quite a bit below the 4.2 league average. His expected YPC works out to 4.1.

The unluckiest (or ‘least fortunate’ if you will) back of 2012 was Beanie Wells. The Cardinals’ tailback averaged a pathetic 2.7 YPC on 88 designed runs. Of those 88 attempts, all but five were against a package that included four or fewer defensive backs. In fact, Wells saw three defensive backs four times, two on three occasions, and one twice. Ouch! Regardless, Wells’ YPC boosts only 0.3, which leaves him with a still-terrible 3.0 YPC. Similar to Ingram, his issue is a poor YPC (2.6) against opposing base defenses. Wells’ expected YPC was 3.9.

To wrap up, I’m going to post four charts. Two will show the luckiest/unluckiest backs of 2012 based on the defensive personnel packages faced. The other two will show the best/worst backs based on how far their actual YPC was above/below their expected YPC. Backs with 45-plus designed runs during the 2012 season (76) qualified.

The Luckiest Backs

Many of the backs you see here make sense. The likes of Sproles, Brown, Woodhead, and Bell work as third-down backs for their respective teams. Moreno and McGahee are probably a bit surprising, but opposing defenses played a lot of nickel against Peyton Manning. The same can be said for Ronnie Hillman and, especially, Shane Vereen.

Stevan Ridley didn’t quite make the cut, but he easily led the NFL in carries vs. a nickel defense. A whopping 205 (or 64 percent) of his 323 designed runs came vs. the nickel. The next-closest back was Mikel Leshoure (124) and only four other backs even reached the 100-carry mark. They are, in order, C.J. Spiller, Willis McGahee, LeSean McCoy, and Ray Rice.

The Unluckiest Backs

Opposite of the previous chart, we see quite a few early-down, between-the-tackles backs on this list. Frank Gore led the NFL with 40 of his carries coming with only three defensive backs on the field. Shonn Greene and Adrian Peterson were next closest with 22 each.

Jackie Battle, Michael Bush, Mike Tolbert, and Andre Brown saw action as their team’s primary goal line back, which meant more bigger bodies in the box on the defensive side of the field.

A popular 2013 breakout candidate, Ryan Williams saw nickel on only 33 percent of his carries. More on him later. DeMarco Murray is another back primed for a breakout next season.

The Worst Backs

“Worst” might be a little harsh, but same as when I say “unlucky”, I’m only referring to performance in the categories at hand.

That being said, it’s hard to put a positive spin on Rashad Jennings’ 2012 season. He averaged 3.0 carries vs. base defenses, and an awful 2.9 YPC vs. nickel. His 2.8 YPC was well below his 4.2 expected mark.

Wells and Williams were very unlucky last season, but they also underwhelmed massively. Both were more than a full yard below their expected YPC. According to our game analysts, the Cardinals easily were the worst run-blocking team in the league this past season, so there’s something to be said for that. Stephens-Howling was on the lucky side in terms of personnel faced, but clearly isn’t an effective ball-carrier.

Interestingly, our four worst-rated run-blocking teams each have at least one representative in the top-10 (Packers, Raiders, Steelers, Cardinals). The Panthers actually rank out as the 10^th-best unit, which doesn’t say much for Jonathan Stewart.

The Best Backs

Considering his absurd 5.9 YPC despite seeing five or more defensive backs on only 53 (or 14 percent) of his 370 carries, it should be no shocker that Adrian Peterson leads this list. His expected YPC of 4.1 was an NFL-high 1.8 below his actual mark.

I’ve always been a fan of Justin Forsett, but his YPC is a bit inflated by an 81-yard Thanksgiving Day run that should not have counted. Even if we remove the 81-yard dash, though, his 4.7 YPC mark would be a half yard above his 4.2 expected mark.

Spiller had a fortunate year in terms of the personnel he faced, but his expected YPC was still well below his enormous 6.0 YPC. It’s also worth adding that we graded Buffalo’s run blocking as 13^th-worst in the league.

The success of Andre Brown and David Wilson show that the Giants are in good hands despite cutting Ahmad Bradshaw (ranked 19^th) loose.

Very much like our previous chart, the PFF run-blocking grades relate well to the success of the backs on these lists. Three of our top-four ranked run-blocking teams (49ers, Vikings, Giants) have at least one representative in the top-10.

Conclusion

It’s important to remember that there a multitude of factors that should be considered when ranking/grading football players. Today, I examined which backs had benefited/been hindered by the defensive personnel they faced during the 2012 season. I didn’t touch on the blocking help each back had (hey, if the defense is in the nickel, that probably means the offense has an extra wide receiver on the field, or from the running back’s perspective, less blocking help). I also didn’t consider how close opposing safeties were to the line of scrimmage, which could be a factor for some of these backs.

That being said, our goal is to maximize the amount of information talent evaluators (that, of course, includes fantasy football gamers) have on each player. The analysis of defensive personnel splits gets us closer to that goal.

Follow Mike Clay on Twitter: @MikeClayNFL