This was inspired by reading this Bill Barnwell piece on Grantland, which looks at the NFL-wide decline in rushing this year, and profiles each back who has lost at least 0.5 YPC over last year. Among them is Marshawn Lynch, down from 5.0 YPC to 4.4 YPC. He (to my mind correctly) attributes it mostly to OL injuries:
When your offensive line is in shambles and running a bunch of backups out there in place of Pro Bowl–caliber linemen on a weekly basis, it's going to drop your yards per carry. The good news is that Okung, Unger, and Giacomini are all back in the lineup, so the Seahawks — and Lynch — should be in much better shape going forward.
What actually struck me, though, is that Lynch is actually experiencing remarkably little drop-off in performance for what a shambles his OL has been in, and note that he also missed lead blocker Mike Robinson for much of the season so far (and a couple games from key run-blocker Zach Miller).
How has it impacted him? Lynch has run for 925 yds (2nd in NFL, 84.1 per game is 4th) at 4.4 YPC (8th among backs with at least 100 carries) and 9 TDs (tied for 1st). By comparison last year he was 3rd in yds, 4th in YPC, and tied for 5th in TDs.
For the advanced-stat inclined, this year he's 4th in rushing DYAR and 11th in DVOA after 2nd and 3rd, respectively, last year. He's also doing more as a receiver (9th and 10th in DYAR and DVOA after 19th and 11th last year) and overall he's 4th in the NFL in yards from scrimmage and tied for 1st in total TDs (4th and tied for 6th last year).
I think it's a real testament to Marshawn Lynch that he's managed to continue producing at an elite level despite all the injuries and blocking issues ahead of him.