Closer look: The Russell Okung effect

The Fox broadcast for the Seattle-Arizona game in Week 10 featured an on-screen stat that caught my attention.

The stat showed the Seahawks averaging 4.4 yards per rushing attempt with Russell Okung at left tackle. The average was 3.3 yards per carry without him. Good stat, particularly with Okung appearing likely to return from an ankle injury when the Seahawks face the New Orleans Saints in Week 11.

I've gone through my play-by-play charting this season and added a column reflecting which player was at left tackle for Seattle on every play. Tyler Polumbus, Okung, and Chester Pitts have taken snaps at the position. This allowed me to differentiate rushing totals by which player was at left tackle.

The Okung effect appears even more significant if we filter out kneeldown plays and quarterback runs. I noted, too, that Marshawn Lynch's first-down rushing average jumps from 2.7 to 3.7 per attempt when Okung is in the game. The increase was less pronounced for Justin Forsett (4.6 to 4.9).

Short-yardage situations also appear vastly different with Okung in the game, although sample size is a limiting factor.

Seattle has gained 10 and 12 yards on its only third- or fourth-1 rushes with Okung in the game (both on third-and-1). The team has averaged 3.4 yards per attempt on these carries with Polumbus at left tackle, counting a 32-yard gain against San Francisco in Week 1. The Seahawks have gained a total of 1 yard on eight subsequent third- or fourth-and-1 rushes without Okung at left tackle.

I included quarterback rushes in these short-yardage totals.

The first chart breaks down rushing averages by personnel grouping, minus kneeldown plays and quarterback runs. For example, the Seahawks have averaged 5.7 yards from 21 personnel (two backs, one tight end) with Okung in the lineup. Seattle has largely abandoned this grouping while playing without injured fullback Michael Robinson.

Overall, Seattle broke two long runs when Pitts was in the game, a 26-yarder by Marshawn Lynch against the New York Giants and a 21-yarder by Leon Washington in the final stages of a game against Oakland.

2010 Seattle Rushing by Left Tackle

Yards per carry for rushes excluding quarterback rushes of any kind.

The second chart differentiates Seattle rushing averages by situation.

2010 Seattle Rushing by Left Tackle

The final chart breaks down rushing averages by running back and left tackle.

2010 Seattle Rushing by Left Tackle