You can't un-learn things

Now that I've done a fair job of establishing that there's no link (or maybe a slight negative link) between a team's passing proficiency and their running game's yards per carry, I can't help but notice claims to the exact opposite all over the place. And by "all over the place," I mean two places where I generally go for better-than-average football analysis and commentary. I still like these sources and I don't really blame them for holding to a thought process that I would also have believed just a few months ago, but it's difficult for me to pass them by without dying a little on the inside.

Yesterday, Daily Norseman posited that:

I think it's fair to say Peterson would see a bump in his yards per carry average with Favre as the team's starter

While the free pdf download of FootballGuys' fantasy football magazine (a great deal, and only 21 MB!), when discussing Matt Forte and the effect Jay Cutler will have on his numbers, asks, on page 111:

1. Will the running game improve with Jay Cutler under center?

And responds with only the following information:

Yards per carry average for all seven Denver RBs last year = 5.17
Yards per carry for Matt Forte last year = 3.9

This, to me, is an egregious oversight by a group of people who should know better. Putting aside the question of whether it's an erroneous assumption, it's a classic case of small sample size. If the Vikings traded for Drew Brees, I could just as easily ask:

Will the Vikings' running game decline with Drew Brees under center?

And respond:

Yards per carry average for all New Orleans RBs last year = 4.15
Yards per carry for Adrian Peterson last year = 4.85

So, clearly, adding Drew Brees will make Adrian Peterson's YPC worse, just as Cutler will make Forte's better. It has nothing to do with any of the involved teams' offensive line, quality of their backs, play calling, run-blocking scheme -- which, it should be noted, Denver has been superb at for years, long before Jay Cutler took over at quarterback -- nope, it's entirely because Drew Brees/Jay Cutler was at quarterback. End of discussion.

(Note that both of these analyses use straight yards per carry as the measuring stick, not the consistency of the back from carry to carry, which is still possibly related to quarterbacking.)

And while I haven't looked over every player's description, the entry for Ryan Grant (page 113) leaves me scratching my head in a number of ways:

There is always a chance that the Grant we saw in 2007 was the anomaly. Without a Hall of Fame quarterback in the backfield, defenses were able to concentrate more on Grant and lessened his impact.

No, not only do we have the "quarterback affects running back's performance" myth to deal with, but there's also the "Brett Favre makes everything better" myth. Aaron Rodgers threw for 4,000 yards and 28 TDs last year. Maybe for the first part of the year, teams concentrated on shutting down Grant, because they didn't know what they'd be getting from Rodgers. By about midseason, though, if you weren't paying attention to Rodgers, he was going to kill you. Grant's disappointing season might also have had something to do with the Packers' defense being so bad as to necessitate the abandonment of the running game earlier than they would have liked.

There's probably more like this in the FG analysis of running backs, and maybe for other positions. It's still a great resource that I heartily recommend, but don't buy into the notion that Matt Forte, or any other back, will have a great season because of improved quarterbacking.