2011 NFL draft: Putting it on line (or not)

The Arizona Cardinals began the Ken Whisenhunt era by drafting an offensive tackle, Levi Brown, fifth overall in 2007.

No NFL team has allocated less draft capital for offensive linemen than Arizona in the subsequent three years, however. Whisenhunt has defended the line's play, particularly in relation to the team's struggles last season. But with all three interior starters unsigned for 2011, this could be the year for Arizona to restock through the draft.

By my calculations, the Cardinals had the oldest offensive linemen in the NFL last season, largely because they tended to have veteran backups.

The chart shows how much draft capital teams have allocated for their offensive lines since 2008. By draft capital, I'm talking about the cumulative draft-chart value for the draft choices used on the position.

For example, the St. Louis Rams used the 33rd overall choice of the 2010 draft for left tackle Rodger Saffold. The trade chart values that pick at 580 points. In 2009, the Rams used the second overall choice, valued at 2,600 points, for tackle Jason Smith. In 2008, the Rams used the 65th overall choice (265 points) for John Greco and the 157th overall choice (29.6 points) for Roy Schuening.

Add up those totals and the Rams have allocated a league-high 3,475 draft points for the offensive line over the last three drafts. The San Francisco 49ers, the only team to use more than two first-rounders on the position since 2007, rank third. The Seattle Seahawks are fourth after using the sixth overall choice for Russell Okung last year and a 2009 second-rounder for center Max Unger.

The trade-value chart isn't perfect. It might become more outdated depending on a how a proposed rookie wage scale affects how teams value early choices. At best, though, the values can provide a guide. And in this case, the guide says the Cardinals could stand to draft a lineman.

2008-2010 NFL Draft Capital: OL Investment Levels

The chart shows how much draft capital teams have allocated for their offensive lines since 2008, using point totals for each selection in a given draft.