Losing Ogden shouldn't hurt Ravens

Forgive your friendly neighborhood Baltimore Ravens fan if he seems a bit distraught today. Jonathan Ogden, a player who might represent the franchise almost as much as Ray Lewis, is retiring.

He will go down in history as one of the greatest left tackles ever, and he's a sure Hall of Famer. The Ravens' offense wasn't very good last year -- it ranked 24th in points scored, even with Ogden in the lineup. What hope does Baltimore have for improving on offense and returning to the playoffs without Ogden to block for Willis McGahee and protect young first-round draft pick Joe Flacco?

Actually, the Ravens' chance of making the playoffs might not be much different today than it would be had Ogden surprised everyone and announced he was returning in 2008. Looking at the recent history of teams that lose a lineman of Ogden's caliber shows those teams aren't necessarily any worse than they were before.

To figure out what losing Ogden might mean for the Ravens, I started out with the top 21 linemen of recent NFL history. That group includes 17 Hall of Famers who retired in 1978 or later, plus four additional linemen who aren't in the Hall of Fame but surely will be soon (Dermontti Dawson, Randall McDaniel, Willie Roaf and Will Shields).

In their final seasons as starters, these 21 players played on teams that averaged 8.4 wins. The following season, those same teams averaged 9.2 wins -- nearly a win better.

Of course, not all of these Hall of Famers still were playing for the teams that made them famous, and very few of them were still playing at a Pro Bowl level. What about teams that lose good offensive linemen in their primes?

I went through NFL rosters and made a subjective 45-player list of top-five offensive linemen who either retired or changed teams in each offseason from 1999 to 2007. For example, in 2007 the list included Derrick Dockery, Tarik Glenn, Pete Kendall, Shields and Eric Steinbach. In 2000, it included Jon Runyan, Jeff Christy, Tony Mayberry, Leon Searcy and McDaniel. And so on.

Here's how the 45 teams that lost a top lineman fared the following year, in both conventional statistics and two of our advanced Football Outsiders statistics -- adjusted line yards (explained here) and adjusted sack rate (explained here):

The teams that lost a lineman clearly got worse, but not necessarily on offense. Remember that in general, teams are pulled toward 8-8 each year. During this same nine-year period, the average 9-7 team won an average of 8.5 games the next year, whether or not it lost a top lineman. Meanwhile, the 45 offenses as a group saw no change in scoring or gaining yardage, and even specific elements such as running back yardage or pass protection didn't change heavily in either direction.

Of course, Ogden is not just another good lineman changing teams. He's the crème de la crème, coming off 11 straight Pro Bowl seasons. What if we look only at teams that lost Pro Bowl linemen?

Unfortunately there aren't many teams to look at. From 1999 through 2007, only 15 linemen didn't return after a Pro Bowl season. Eight linemen switched teams, six retired and one, Korey Stringer, tragically passed away.

Here are those same stats for the teams that lost a Pro Bowl lineman:

The numbers look pretty similar, don't they? The stat that seems the most significant is running back yards per carry, but the adjusted line yards numbers suggest we're seeing 15 teams whose running backs declined, not 15 teams that suffered because they lost Pro Bowl blockers.

It seems odd that teams don't seem to struggle when they lose a top blocker.

But plenty of examples say otherwise. We know that the New York Jets had no way to replace Pete Kendall last season, that the Seattle Seahawks had problems without Steve Hutchinson, and that the Kansas City Chiefs' offense completely crumbled without Roaf and Shields. On the other hand, LeCharles Bentley was supposed to be the only good lineman for New Orleans in 2005, but he signed with the Browns and never played a down for them, whereas the Saints had a miracle season without him. Ruben Brown left Buffalo for Chicago in 2004, but the Bills nearly doubled their scoring.

Perhaps the best example of a team losing good linemen without a problem is the 1999-2000 Minnesota Vikings. The Vikings were the only team to lose two Pro Bowl linemen in the same offseason, when Jeff Christy and Randall McDaniel both left for Tampa Bay. Without them, the Vikings finished within two points of their scoring total from the year before. They allowed fewer sacks per pass play, and the running backs collectively went from 4.3 yards per carry in 1999 to 5.0 yards per carry in 2000.

Do these numbers mean that good offensive linemen are overrated in general? Not at all. Not many top linemen are like Ogden and play their entire careers for one franchise. There might be surprisingly little impact when a team's offense loses a top lineman, but there's a major impact when it adds one.

Remember our group of 45 top linemen who left their teams between 1999 and 2007? Ten of those players either retired or signed with expansion teams, and another was Stringer. This is what happened to the offenses that signed the other 34 top linemen:

In general, Football Outsiders research has shown that offensive lines play better when the five linemen have continuity and experience playing together. On the other hand, there's clearly a reason to set aside continuity if a team can add a top lineman in free agency or trade. On average, the teams that added a top lineman won more games, gained more yards and allowed fewer sacks, and these numbers would be even better if we didn't count the 2006 Browns (remember, Bentley never actually played for them.)

The history of teams losing good linemen gives Ravens fans a reason for optimism. However, Ogden isn't the only Pro Bowl lineman who won't be back in 2008 … back in the same place, that is. The team that really can look at these numbers and feel optimistic about returning to the AFC playoffs is the team that signed the only Pro Bowl lineman to change teams this offseason -- the New York Jets, who now feature the blocking skills of Alan Faneca.