The game is won in the trenches, I know.

As we hit the halfway mark of the season, some teams are already thinking about next year, and in particular, the 2013 draft. If I was in charge of a bad team, and specifically, a bad passing team, I would try to avoid spending a lot of money or a high first round pick on a left tackle. This philosophy is more guideline than rule — if there is a can’t miss prospect there and/or you are underwhelmed with the other top prospects, then draft the tackle — but spending a high pick on an offensive lineman would be my move of last resort.

Let’s pretend for a few minutes that a top-five pick on a left tackle is going to give you Jake Long or Joe Thomas or Jonathan Ogden, and not Jason Smith or Levi Brown or Robert Gallery or Mike Williams. Now, why is having a star left tackle so valuable? The traditional theory goes that since the left tackle is response for protecting the quarterback’s blind side, he’s the most important member of your offensive line. The other corollary is that most star pass rushers play on the defense’s right side (and the offense’s left), amplifying the value of the left tackle.

When it comes to the running game, the left tackle is no more valuable than the right tackle, or (in some systems) any other members of the offensive line, for that matter. To make this a more straightforward analysis, let’s just stick to the passing game, even though obviously most elite left tackles are also very good at run blocking, which of course adds value.

On most passing plays, offensive linemen are basically the equivalent of fences, designed to prevent the opposition from getting to the quarterback. How useful is a fence that’s totally impenetrable on the left side but has a human-sized hole on the right? This isn’t just a snarky comment; an offensive line is often only as valuable as its weakest link. Which defense will get to the quarterback first: one facing five average linemen or one facing three average linemen, an All-Pro left tackle and the worst starting right tackle in the league? If you were a defensive coordinator, which group would you rather scheme against? To me, it’s a pretty simple question: you want to attack your opponent’s weakness, and an offensive line, like a fence or a chain, is only as strong as its weakest link.

Let’s put it another way. In what circumstances does an All-Pro left tackle add value over say, the 25th best starting left tackle in the league? I think those circumstances are basically limited to those plays where:

The All-Pro left tackle does his job, and the other four, five or six blockers do their job, and the quarterback makes the right read and an accurate throw, and the receiver makes the catch, and on this particularly play, the player(s) that was (were) blocked by the All-Pro left tackle would have gotten to the quarterback in time to prevent him from throwing and completing said pass had he (they) been blocked by a replacement-level tackle.

If you think there are a lot of ‘ands’ in that sentence, you’re right. If the other lineman don’t do their job, the star left tackle is meaningless. If the quarterback can’t make the right read or is inaccurate, the left tackle that blocks DeMarcus Ware doesn’t help his team (other than an incomplete pass being better than a sack or a rushed throw that turns into an interception). If the receiver drops the ball, the left tackle doesn’t provide any value. And if we’re talking about a player where the left tackle didn’t do anything that a replacement level linemen wouldn’t have done, then our star tackle has added no value, either.



That’s a lot of theory, but we have practical results that confirm this. Joe Thomas and Jake Long are fantastic left tackles, perhaps the best two at the position over the last half-decade. But they haven’t done much for their teams because Cleveland and Miami have had so many holes. That doesn’t make them less excellent at their craft, it just means they’ve provided less value. Essentially, the left tackle is a luxury for teams that are strong everywhere else.

But don’t take my word for it. When Doug Drinen created the Approximate Value system at PFR, he ran into a problem which required a fix:

I’ve instituted a minimum AV for first-team all-pros, second-team all-pros, and pro bowlers. We may as well call this the Jonathan Ogden rule, because he’s the guy who demonstrated the need for it. The AV formula, because it starts with team success, hates Jon Ogden. Ogden is essentially the opposite of Derrick Brooks, who ranks surprisingly high in AV largely on the basis of being the lone constant on one of the best 12-year team defensive runs of all time. According to my metric of choice — points per possession — Ogden has played on a below average offensive team for 11 of his 12 seasons, some of them way below average. As a result, there just haven’t been many points to divvy up among the Raven offensive players. So when I run through the formula, Ogden gets a lot of points relative to other Ravens, but still not as many points as he probably should. The AV methodology essentially implies that a terrible offense can’t have any great players, and that’s not true.

Doug was trying to create a system that would allow comparisons across eras and positions; comparing Jonathan Ogden to Fran Tarkenton is pretty difficult, but Doug’s “fix” made sense. But for our purposes, an interesting dichotomy emerges. What Doug’s system *was* doing before his fix was showing you how much value each player provided. And to be frank, Ogden simply didn’t provide a ton of value (in the passing game) to the Ravens, because there were so many other ways Baltimore could mess up on offense besides “letting the right defense end get to the quarterback.” Doug’s fix made sense when we as fans would try to compare Ogden to Tarkenton, but not if we were trying to figure out how much value Ogden provided.

Maybe you think I’m being a little academic trying to magnify the small gap between ‘how good a player is’ and ‘how much value he provides.’ But there is a real distinction, and you need look no further than Ogden’s contemporary to see it in action. Orlando Pace was the first pick in the draft in 1997 and was expected to be a dominant left tackle. His first two years in the league, St. Louis won just 9 games and had ugly offenses. In 1998, he blocked for Tony Banks and Robert Holcombe while playing for a Rams team that had Ricky Proehl and Amp Lee as its leading receivers. In 1999, Pace was a first-team All-Pro selection, oh and he blocked for Kurt Warner and Marshall Faulk and Isaac Bruce and Torry Holt were his team’s starting wide receivers. When the Rams scored 49 points against the Vikings in the playoffs, Pace added a lot of value when he lined up against Chris Doleman. When he was doing his job in 1998, how much value did he really add?

This is the same problem Dermontti Dawson faced, and I wrote about it when discussing why he should be in the Hall of Fame. In 1998, Dawson was a first-team All-Pro at center despite the Steelers ranking 28th in points in a 30-team league. But that’s because blocking the other team’s defensive tackles extremely well doesn’t mean all that much when the bad version of Kordell Stewart is throwing to Charles Johnson, Courtney Hawkins, and Will Blackwell.

The truth is, for an offense that’s filled with holes, spending a lot of money in free agency or a high first round pick on a left tackle is a luxury those teams can’t afford. On a fully functioning offense, an average left tackle might hold your team back more than an average player at any other position besides quarterback, as the best pass rushers in the game will do their damage in that situation. But for bad teams, they should focus on fixing the gaps elsewhere first, or else they’ll wind up playing whack-a-mole (or looking like the Browns).

And, of course, it’s worth pointing out that left tackles are far from safe picks. In the mid-’90s it seemed like a wise move — Tony Boselli, Ogden, and Pace were drafted in consecutive years and all were excellent. Three years later, Chris Samuels was the third pick in the draft, and the Redskins received a decade of strong play from him. But since then, there have been more busts (Mike Williams, Robert Gallery, Levi Brown, Jason Smith) and disappointments (Leonard Davis, D’Brickashaw Ferguson) than hits (Jake Long, Joe Thomas), with the jury still out on Matt Kalil and Trent Williams.