Since Lawrence Taylor’s arrival on the NFL scene, general managers have placed a higher value on protecting their highest-dollar investment – the quarterback – and so understandably, salaries for tackles have risen greatly.

Therefore, it’s no surprise that a franchise tackle is a hot commodity on draft day. In the 2011 draft, six were taken in the first round in 2010, and four in 2010. Then, there was the 2008 draft in which eight tackles were chosen as first-rounders.

The big question is this: are they generally worth it? I took a look at each tackle selected in the first round from 2003 to 2011 – that’s 38 total players – and found some mixed conclusions.

The first thing that stood out was that most first-rounders are good enough to contribute something in their first few years. The average rookie first-round tackle since 2002 started 10.4 games, and over the first four years averaged 46.1 starts. The second number is particularly important, because that’s how many years teams generally have their first-rounders under contract, though clubs can exercise an option for a fifth year.

Secondly, it was interesting to note that few tackles wind up being total busts. Of the 17 players selected between 2002 and 2008, all played at least five years. The Bills’ Mike Williams (No. 4, 2002) made it only that long and is widely considered a bust, though injuries didn’t help.

Injuries hurt a few other guys, too. Jeff Otah (18^th, 2008), Shawn Andrews (No. 16, 2004) and Alex Barron (19^th, 2005) all missed substantial time for being hurt. The recent outlook for Otah and Barron hasn’t been good, but at least they’re still trying to stick around. Andrews might have potentially become one of the all-time greats, but finally hung it up a couple years ago when he couldn’t keep his back healthy.

Anyway, the point is, if you take a tackle in the first round, he’ll still be contributing several years down the road so long as he’s not hurt. Of course, teams don’t want first-rounders to just be on the field; they want elite production. How did the group do in that regard?

Obviously, it’s harder to keep meaningful stats for offensive linemen than for any other position group. Generally, we rely on things like Pro Bowl selections and All-Pro selections. Of the 166 player seasons in the sample, 19 resulted in Pro Bowl seasons. More importantly, since teams might not retain rights to those players after four years, 15 of those came in a player’s first four seasons.

If you measure players by the more elite first- or second-team All-Pro honor, you’ll find Andrews, Joe Staley, Duane Brown and Jammal Brown with one each, Jake Long with two, and Joe Thomas with three. That’s not terrible, considering only four to six (depending on whether there are ties) are selected each year, and Thomas, Duane Brown and Staley accounted for three of the five last year.

So, we’ve measured players by stick-around value and top-level greatness, but haven’t really broached the middle ground where most players lie. Again, we’re limited by stats, but I really like something that ProFootballReference.com founder Doug Drinen invented called “approximate value” (or “AV”). It’s Drinen’s attempt to put a value in the form of a simple integer on every player’s season regardless of position. Here’s a link to where Drinen explains his methods, and while he admits it has flaws and the explanation is lengthy, it’s worth a read because it’s about as good an attempt as anyone’s made at this sort of thing:  http://www.pro-football-reference.com/blog/?page_id=518

Drinen places a great emphasis on the word “approximate” when referring to his value system, saying that if one player is a “16” and another a “14,” it’s hard to say with certainty which was the better player. But Drinen also surmises that a group of 16s will out-perform a group of 14s with regularity, and since we’re dealing with large groups, this works for us.

For a point of reference when it comes to AV, many consider Anthony Munoz to be the greatest offensive tackle ever. Munoz has an average approximate value of 14.5. If you want to set the bar a bit lower, let’s look at the four tackles on the two most average offenses last season – the Bears and the Raiders – who are Lance Louis, J’Marcus Webb, Khalif Barnes and Jared Veldheer. Louis started 13 games, and the rest, all 16. Their AV’s, respectively, were 4, 6, 7 and 8, for an average of 5.75.

How did our 38 first-rounders fare? Averages per year:

1^st:            5.1

2^nd:           7.2

3^rd:            6.7

4^th:            5.8

5^th:             5

6^th:            6.1

7^th:            5.7

8^th:            6.7

Remember, the first year group takes a hit because it started only 65 percent of the time. Years two and three look good, but everything beyond that is rather pedestrian performance; while Year 8 looks good, it’s only a sample size of three.

Of course, we’d really need to compare first-rounders all positional groups to the field at their position (and perhaps even increase the sample size to past years) before we could make much of a judgment on whether the value you get from a tackle is worth the first-round risk, but I’m a bit surprised that the top-end results weren’t better. Perhaps there’s a good reason that teams like the Titans (who didn’t select a first-round lineman during those 10 years) use their top selections elsewhere.

It’s an interesting question that will take some time in the future to explore, and one certainly worth asking.