Draft Metrics: Offensive Tackle

Most teams approach building their offense through the trenches, specifically focusing on the offensive tackle. A dominant player can lock down the position for over a decade, and positively impact both the running and passing games. For this study, I've taken draft data from 1996 to 2008 (2009 data hadn't been updated yet). In assessing a player's performance, I'm looking at two tiers: games played per years available to judge whether a player is starting caliber, and Pro Bowls per year available to screen out elite players.

There were 256 tackles selected between 1996 and 2008. 32 of these have played 15 or more games per season (top starter) over their career, and 43 more play 12 or more games per season (adequate starter). An additional 54 appear in more than 6 games (stopgap starter/backup). The remaining half of selections are backups at best, and should be trivially replacable. Full data is here.

Round 7:
Of 41 selections, 1* is strong (J.Richard), 5 more are adequate, and 5 more are stopgap solutions.

Round 6:
Of 39 selections, 1 is strong (C.Johnson), 1 is adequate and 4 are stopgaps.

Round 5:
Of 34 selections, 1* is strong (C.Nicks), 2 are adequate and 8 are stopgaps.

*- both players have been in the league one year, so longterm success isn't guaranteed yet.

Round 4:
We start to see the quality pick up a little. Of 35 selections, 2 are strong (J.Evans, J.Runyan), 6 are adequate and 9 more are stopgaps. Both strong players have made a Pro Bowl, the lowest picks earning this distinction.

Round 3:
Looks much like round 4. Of 35 selections, 3 (A.Snyder, E.Winston, M.Starks) are strong, 7 are adequate and 9 can plug a hole in a lineup.

Round 2:
A noticeable increase in quality again. Of 28 selections, we see 7 strong players, 11 adequate starts, and 6 more stopgaps. Only 4 players (M.Pearson, W.Justice, J.Roque, J.Rogers) in 13 years fall below stopgap. We also see numerous Pro Bowl-level players (M.Roos, M.McNeill, F.Adams, C.Clifton, M.Light, ... )

Round 1:
Scouts earn their paychecks for this position. Of 44 selections, 17 are strong starters, 11 more are adequate and 11 are stopgaps. 5 players are busts. While the bucket numbers are pretty close to round 2, round 1 tackles have earned a combined 53 Pro Bowl nods vs 13 for round 2 picks.

Conclusion:
The late rounds produce about one starter per 10 picks, so don't get your hopes too high for that raw prospect. However, another 1 in 7 picks become decent backups, so there's a combined 1 in 4 chance your team will find a quality roster player here. The odds roughly double when picking in the 3rd and 4th round; per 4 players, 1 will be a starter, another will be a backup. 2 out of 3 players from the top rounds will be a solid starter or better. Though Pro Bowl selections are dominated by 1st rounders, a savvy team can build a strong line with 2nd-round picks and keep costs considerably lower.

Top offensive tackles should be located in the first two rounds, but upgrades to weak players can be readily found in the middle of the draft, and depth behind an otherwise solid line can be addressed with late-round picks.