So this is why they call it 'tackle football'

Miami's Jake Long, an elite left tackle, will earn $11.2 million this season (US Presswire)

When the Miami Dolphins had the first pick of the 2008 draft, they didn't choose quarterback Matt Ryan. They took left tackle Jake Long instead, and that was a mistake. Franchise quarterbacks take clubs farther than franchise left tackles.

But cut the Dolphins some slack. First of all, they won the division that season; second, you can never have enough good pass protectors, especially when they play the left side.

And we just discovered why.

I'm talking about what happened to Chicago on Monday night when San Francisco's Aldon Smith ran over, around and through the Bears' tackles for a career-best 5.5 sacks -- more in one evening than all but 32 pass rushers this season.

Elite pass rushers are prized. But so are reliable left tackles, and, trust me, there aren't many of them. Jason Peters is one, but the Philadelphia Eagles lost him to an Achilles injury before the season and never recovered. Cleveland's Joe Thomas is another, too. So are Denver's Ryan Clady and Washington's Trent Williams.

In the last five drafts, 22 offensive tackles were taken in the first round, including four in the Top 5 and eight in the top 10. Of that group, all but four start, with a fifth (Green Bay's Bryan Bulaga, a starter until he was hurt) sidelined for the season.

So there's a premium on elite tackles, with the position the third-highest paid in the game. The problem is: There just aren't enough to go around, and Aldon Smith and the San Francisco 49ers just proved it.

"These guys are far from finished products when you get them," said an NFC player personnel director. "Sometimes you're just looking for the guy who has the work ethic and the ability to play at the NFL level. Over time you develop technique and tricks of the trade -- like 'cheating' with your hands -- and that's an art. But it's always talent first. That's why it's such a hard position. Everyone's looking for that guy to hold off Von Miller or Clay Matthews."

That was why Miami jumped for Long in 2008. Too many clubs this season are scrambling to protect their quarterbacks, and Chicago is one of them. But Arizona's tackles are awful, and the offensive lines of Philadelphia and San Diego are so depleted that they look more like open windows.

Each one of those clubs was supposed to be a playoff contender. Each one is not.

"Everyone is looking for the perfect left tackle," said one AFC general manager, "and if you don't have him you don't have a lot of hope. Worse, if he's really, really bad you're going to be in big, big trouble."

That's why elite pass rushers get paid a lot of money, and it's why elite left tackles get paid almost as much. They protect the blind sides of right-handed quarterbacks, and with most quarterbacks fitting that description you want reliable bodyguards.

But be prepared to pay.

The Eagles' Peters earns an average annual salary of $12.8 million, while spotrac.com has Long checking in at $11.2 million this season, Washington's Williams at $11 million and Thomas at $10.5 million. Then there's Clady, who protects Peyton Manning. Last summer the Broncos offered him a five-year, $50 million deal that reportedly included $28 million in guarantees.

You don't see the names of, say, Chicago's J'Marcus Webb or Gabe Carimi in there, and I don't expect you will. They were supposed to serve as Jason Campbell's pass protectors Monday night but acted as speed bumps for the 49ers' Smith. He bull-rushed Carimi. He went around and through Webb. In short, he did whatever he wanted, and that told me something about Smith as an edge rusher.

But it told me more about the trouble Chicago will be in down the stretch.

"Next to quarterback, I make the left tackle the priority right there with an outside pass rusher," said one GM. "No matter what the scheme is -- whether it's college stuff or West Coast offense -- you have to have a left tackle who can pass protect. You can always teach him how to block for the run, but if you can't find someone who can protect the quarterback you're finished."

That's true now more than ever because the NFL is a passing league where last year three quarterbacks threw for more than 5,000 yards -- a figure eclipsed only twice before 2011. But throwing more means more hits for quarterbacks, and two weekends ago four were sidelined during games, including three (Michael Vick, Alex Smith and Jay Cutler) with concussions.

Then there's San Diego's Philip Rivers. He hasn't missed a start in his career, but the Bolts' inability to protect him has taken its toll. Two years ago Rivers threw for a league-high 4,710 yards when injuries reduced the Chargers' roster so significantly they suited up an NFL-record tying 74 players. No problem, Rivers found 17 of them with passes.

He was accurate. He was confident. And he was successful.

But look at him now. He has 43 turnovers the past two seasons. Nobody has more. He makes mistakes that defy logic, with that second-half interception in Tampa Bay the most obvious. He seems out of sorts. He seems rattled. And he's no longer successful, with a 21-22 record over his last 43 starts, including the playoffs.

"Mentally," said one scout who asked not to be identified, "he's been destroyed."

I don't know about that. What I do know is that when you rotate left tackles as San Diego has ... when you lose your two starting guards as the Chargers did in last weekend's loss to Denver ... when you rely on an undrafted free agent to protect Rivers' back ... there are bound to be repercussions. And you saw them last weekend when Denver's Von Miller blew through the pass protection for three sacks.

The Chargers thought they had the position covered in the offseason when they re-signed Jared Gaither, then an unrestricted free agent. Given their options, they had no choice. They made an offer, crossed their fingers, then watched Gaither -- who played well the last five games of 2011 -- shelved by a variety of injuries, including a lingering back issue, to create a problem that won't go away.

Now they're on life support.

The good news for them ... and others ... is that there's help around the corner. The bad is that you can't turn that corner until next April's draft. According to our own Rob Rang, Texas A&M junior Luke Joeckel is the top-rated prospect in the country, with Michigan's Taylor Lewan a legit left tackle with a chance to be a top-20 choice.

Oklahoma's Lane Johnson is another first-round possibility, as is Central Michigan's Eric Fisher, the top senior tackle in next year's class. It's not a draft rich in tackles, but it is a draft that offers interior help -- and help is what teams like San Diego need.

Look, Miami had the right idea in 2008, but the Dolphins forgot they didn't have a franchise quarterback for Jake Long to protect. Find the right quarterback, protect him and you have a chance to go far. Fail on either score, and you're Chicago ... or San Diego ... or Philadelphia ... or Arizona.

"And that," said one scout, "is why you don't find great left tackles in free agency. If you have one, you keep him."

And if you don't, tell your backup quarterback to get loose.