18 Aug 2007
Sometime after the NFL draft I finally got around to reading Michael Lewis' excellent book The Blind Side. The book tells two interwoven stories: the amazing personal story of Michael Oher and the dramatic shift in the NFL that made him, a left tackle product, so intriguing. Basically since the arrival of Lawrence Taylor, teams have been obsessed with attacking and protecting quarterbacks from the blind side.
As a Colts follower, the book particularly resonated because the Colts had recently traded away their 2008 first-round pick for the right to select Tony Ugoh. At the time, the selection marked 2007 as the last season for long-time tackle Tarik Glenn, the starter at left tackle for basically Peyton Manning's entire career.
I thought the lack of media coverage of this move was amazing, particularly given the Sturm und Drang that surrounded the Eagles selection of Kevin Kolb. The Colts effectively declared that their Pro Bowl left tackle would not be re-signed after this upcoming season, and nobody seemed to blink. Clearly the media was still fixated on skill position players, while the league was focusing on linemen. Three of the top five picks in that draft were players who are supposed to either attack or defend the quarterback's blind side.
Since the draft, Glenn decided to retire immediately. A Colts offense that planned to return all their Super Bowl starters now is protecting Manning's blind side with an untested rookie. A year ago, the Colts survived the departure of their Pro Bowl running back, Edgerrin James. The assumption now seems to be that as long as the Colts have Manning (or at least Manning, Marvin Harrison, and Reggie Wayne), then the offense will be a juggernaut.
Running back and left tackle, however, are not the same position. Everyone at Football Outsiders, save me, predicted a year ago that the Colts would not miss James much if at all. But, we often emphasize the importance of offensive linemen. If Manning cannot feel comfortable with the rush from behind, he'll get happy feet and cease to be a dominant player. If the left tackle cannot hold the corner on the stretch play to the left, the Colts run attack will stall.
Part of the reason for calm is likely the sense that Glenn was not a dominant player. That may be the case, but more importantly, Glenn was never dominated. He was a second-tier tackle in the dominant era of left tackles. A contemporary of Walter Jones, Jonathan Ogden, and Orlando Pace, Glenn was easy to overlook as a very good but not great tackle for almost a decade. Glenn has been a solid pass protector but also excelled in run blocking, the other essential attribute of a quality left tackle.
Glenn's true value is difficult to measure due to the Colts unique system and the lack of offensive line statistics. The Colts do not require their offensive linemen to hold their blocks as long, and the heavy reliance on the stretch play in the run game emphasizes agility over brute force. As a result, traditional scouting can fail to accurately analyze Glenn's ability.
Statistically, the best we have is adjusted line yards to measure run blocking prowess. The stat is imperfect at identifying the ability of an individual offensive lineman. Still, it is worth noting that the Colts ranked first in runs behind left tackle last season and in the top six in five of the past seven seasons. They have ranked in the top 10 in runs around left end in six of the past seven seasons. The one exception was James' post-ACL season when the Colts' rushing offense was atrocious in general. (Pass protection stats are even sparser, but it should be noted that our game-charting project only ascribed two sacks to Glenn all season.)
One other place to look for Glenn's impact is the 2003 season where Glenn missed six games, the only injury of his career. Thanks to the premium DVOA database (remember, now available for purchase), we can see how the Colts performed in the games he missed. Glenn missed the games in Week 6, 8, 10, 11, 12, and 13. For those six games, the Colts average offensive DVOA was 17.4%. In the Colts' other ten games, their average offensive DVOA was 16.2%.
While those numbers are encouraging to Colts' fans, a large part of the discrepancy was a disastrous season-opening game against the Browns where the Colts offense posted a DVOA of -30.4%. Eliminate that game, and the Colts averaged 21.3% in the other nine Glenn games. Eliminating that game may not seem fair, but if memory serves (and I could be wrong), the Colts switched to a predominately no-huddle offense after the Cleveland game.
Even so, the four percent difference is hardly a massive discrepancy. Maybe the Glenn retirement will be just a minor nuisance easily overcome by Manning, et al. Also, while Ugoh is unproven, he is not exactly a street free agent. He is a second-round pick who the Colts obviously loved even before they knew Glenn was retiring. By all accounts, Ugoh could develop into an excellent left tackle in his own right.
Still, Glenn was a very good player for a long time at a crucial position. The Colts ability to overcome the loss of James is Exhibit 1 on the fungible nature of running backs. If the Colts don't miss a beat without their Pro Bowl left tackle, what does that say about the fungible nature of left tackles? Or does the dominance of Manning and astute drafting by Bill Polian make the Colts a poor team to use for a league-wide principle? No matter what, the Colts' offensive fortunes without Glenn are a story worth watching and perhaps a data point in the continuing struggle to determine the relative worth of offensive positions.
8 comments, Last at 20 Aug 2007, 3:57pm by doktarr
Trevor Siemian and Carson Wentz rank in the bottom three in average air yards. Do good quarterbacks usually increase their air yards with more experience, or do their passes actually get shorter over time?