A few weeks ago, I discussed why I selected D’Brickashaw Ferguson as my left tackle in the RSP Writer’s Project. In the comments to that post, mrh argued that tackles generally don’t age that well, a proposition I never really considered before. I have previously discussed quarterback age curves and examined running back aging patterns last summer, so I’ve decided to take a closer look at offensive tackles.

First, I grouped together all tackles who entered the league since 1970 and recorded at least four seasons with an Approximate Value of at least 8 points (Ferguson has three seasons with an AV of 8 and two more with an AV of 9). That gave me a group of 78 tackles who were above-average players in their prime. As it turns out, they didn’t age very well as a group, and the results probably underestimate the true effects of age.

As I’ve discussed before, there are two ways to measure group production over a number of a seasons. In the graph below, the red line shows the aging patterns of top tackles when you divide their total AV accumulated by tackles at that age by 78; the blue line shows the age curves when you divide the total AV accumulated only by those tackles active in the NFL at that age.
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