Monday, July 30, 2007

A Dominant Offensive Line?

The Vikings are willing to trust that Tarvaris Jackson can run a competent air attack because of their confidence in their ability to run the ball. And while Chester Taylor is a solid back and Adrian Peterson has all of the talent in the world, the Vikings’ faith in their running game is due to their faith in their offensive line. And considering how much money they’ve invested in their line, they had better be confident in its ability to open massive holes for their skilled backs, not to mention their ability to give Tarvaris Jackson a chance to develop as a quarterback, rather than as a scrambler.

Was the money well spent? Should the Vikings be confident in their offensive line’s abilities? According to this year’s Pro Football Prospectus (PFP), the answer is yes…and no. [Just so everyone knows, I’m going to be drawing from the Prospectus the entire preseason. This book is awesome, with an amazing amount of statistics and is quite well written. Like Baseball Prospectus, it is a required purchase prior to the season.]

As you’d expect, the Vikings’ line was pretty good last year. However, it was not the dominant force the team needs. It was above average in the running game, but well below average in protecting the passer and nowhere near as dominant in the run game as one would think a line with Bryant McKinnie, Steve Hutchinson and Matt Birk would be. Whether that was due to the incompetent quarterbacking, the weak quality of the right side or McKinnie’s broken hand, depends on who you ask. By using PFP’s statistics, however, the answer becomes a little clearer.

Prior to consulting any statistics, my hunch would be that the line’s inability to dominate the pass rush had to do with Brad Johnson’s immobility. Their adjusted sack rate (ASR) , which is calculated by adding sacks and intentional grounding and then dividing that by pass plays and adjusting for situation, ranked 22nd overall at 7.6%. To put that in context, the Colts’ line had the best ASR in the NFL at 3.4%. This stat is also kept for quarterbacks, however, which allows you to better determine whether the sack was the line's fault or the quarterback. And it implies my hunch was incorrect. Brooks Bollinger and Tarvaris Jackson went down frequently, with ASR’s of 24.3% and 8.7% respectively, while Brad Johnson actually had a lower ASR than the offensive line, with a 5.9%. Bollinger’s career ASR is actually worse than David Carr’s and Tarvaris is a rooke that likes to run, neither of which bodes well for a line trying to keep their QB upright.

Even when the quarterback handed the ball off, the Vikings’ line didn’t dominate as much as would be expected. And the problems weren’t on the right side like you'd think. PSP’s charting has broken down the yardage gained depending on where on the line the back ran, recording each run off left end, left tackle, middle, right tackle and right end. One would think that the Vikings’ were completely above average going to the left side, but that isn’t what the statistics show. In reality, there worst outcomes came off of left end, where they averaged 3.00 yds/carry, in comparison to a league average of 4.12. The Vikings were above average on every other part of the line, with their greatest success coming off of right end, where they ran for 5.15 yds/carry, more than a yard better than the 4.08 average. They were also successful off of left tackle (4.85 yds/carry, compared to a 4.36 average) and off of right tackle, at 4.54 yds/carry, with the league averaging 4.21 yds/carry. Up the middle, however, they were middle of the road, gaining 4.33 yd/s carry, almost exactly the same as the 4.32 league average.

This information seems to back up the idea that the right side of the line was the weak point, as well as demonstrate that Matt Birk was not as effective as he was prior to his hernias. Even with Steve Hutchinson to help, running the ball up the middle behind Birk and Artis Hicks was in effective. And running the ball outside to the left, behind a pulling Birk or Hicks was an exercise in futility. But when Hicks or Birk were deemphasized, the Vikings ground game was in the top six, whether it was behind Bryant McKinnie or a pulling Steve Hutchinson. And it seems that Ryan Cook and Marcus Johnson were competent at doing their jobs in the running game.

Based on last year's statistics, it seems the Vikings don't quite have the quality of line they need for their running game to carry their offense. They are set at left tackle and left guard, but their center is aging and losing effectiveness. Not to mention the fact that Artis Hicks wasn’t worth acquiring and Ryan Cook is still a question mark. The Vikings should still be effective running Peterson and Taylor behind McKinnie and Hutchinson, but the reality is that it won’t be enough to remove the pressure from Tarvaris Jackson and his merry band of receivers to keep the offense moving. And it won’t help that they’ll have problems keeping defenders off of Tarvaris either, something that won't help him develop the instincts he needs to determine when to run and when to hang in the pocket.

No comments: