3. RIGHT GUARD

Eric Steinbach signed a seven-year, $49 million contract prior to the 2007 season. Thomas E. Witte/SI

Without question the most difficult of the interior line positions, right guards are most likely to be left one-on-one with an elite inside rusher. The predominance of teams to slide their center to the left to protect the quarterback's blind side creates a greater value for the right guard position. Fourteen-year veteran Todd Steussie, currently available on the free agent market, says, "Right guard is definitely harder than left guard." Recently-retired lineman Todd Fordham, a 10-year NFL vet, agreed: "The left guard always has help."

Though the difference in value between the two guard spots is lessened somewhat in an offense that rarely slides the pass protections like the Colts, the strength of the formation often dictates that the right guard has the wider alignment, and thus more difficult assignment, on his side.

4. LEFT GUARD

Because the left guard position is generally less difficult than the right guard position, I have been consistently perplexed the last couple of seasons by the amount of money teams are investing in the position.

Steve Hutchinson, Kris Dielman, Eric Steinbach, Derrick Dockery and Faneca lead the parade of left guards that have received contracts in excess of $40 million. Though I am not sure either guard position is worth that much of the salary cap, I would be much more willing to pay those dollars to a right guard given the greater difficulty in his assignment. I think the Browns got a relative steal by signing right guard Rex Hadnot to a two-year, $7 million deal this offseason.

The greatest reason why left guards are cashing in these days? There are two: 1) The grading system for offensive linemen; and 2) General lack of understanding among some NFL personnel people concerning the difficulty inherent with the different positions.

All of these players are considered upper echelon and likely grade out among the highest linemen on their respective teams. Part of that is because they are good players, but a lot of it has to do with the fact they are much more likely to receive help from the center and thus less likely to create a negative play. The formula is simple: Less one-on-ones against defensive linemen means less chances to give up a sack or pressure. Their consistently high performance given the lower risk at the position tricks many personnel people to assume they are worthy of that money. I disagree. I believe they are all outstanding players but think they would have a tougher time if they played right guard.

There is a reason why most of the interior guys getting paid the big money are left guards and not right guards and the sooner teams can figure it out, the sooner they can begin to allocate more of their money to a position that creates a greater value proposition.

5. CENTER

Centers are paid more for their intelligence and experience than they are for the difficulty associated with their physical assignment. Though some athletic centers can create additional value with their ability to pull or effectively block at the second level, the greatest reason centers get paid well is the fear among coaches that their pivot man not be able to readjust the blocking scheme depending on a certain blitz look or audible. Make no mistake about it: A center that cannot make the right decisions at critical junctures could have a huge impact on the outcome of a game.

That being said, it was unanimous among the four offensive lineman that I polled that center was the easiest position, at least physically, along the line. The center is rarely in a one-on-one pass blocking situation, which as we have noted, is the most likely situation in which an offensive linemen could have a large impact on the outcome of a game.

Centers are often the ones providing the help in pass protection so it is surprising to me that teams like the Buccaneers value the position highly enough to reward a player like Jeff Faine with a contract that guarantees him $15 million. Most centers go through an entire season without giving up any sacks and are rarely credited with even being responsible for a pressure.

Though every team wants to have a highly-regarded player at every position, the economics of the game do not allow that to be the case. That is why the money invested in the offensive line should be given first to the tackles and then to the right guard, since those are the positions that could potentially make the greatest difference between a win and a loss.

Ross Tucker has played for five teams in his seven-year NFL career. He has joined SI.com as a regular contributor on the NFL beat. Send comments to siwriters@simail.com.