For skilled players coming out of high school, the ability to play more than one position makes you a hot commodity. If you can throw a good 15-yard pass on one play then catch a pass on the next, college head coaches will be busting down your door with scholarship offers and promises of glory.

But on the offensive line, that special talent is almost an expectation over a luxury.

This trend is becoming so commonplace that many fans don’t even notice or care when their team makes a change in the trenches. To the untrained eye, a revolving door on the offensive line may not seem chaotic, but each position on the line has different responsibilities and requires a different mindset and skillset.

The center, often called the quarterback of the offensive line, is responsible for reading the defense and making the necessary adjustments at the line of scrimmage. In the running game, the center has to make a quick read for the defensive alignment, most often either the 4-3 or the 3-4, and set up the blocks accordingly.

In the 4-3, the center is often the only offensive lineman without a defender lined up across from him, meaning he is responsible for making the first second-level block on a linebacker or a blitzing safety that can be the difference between a one-yard gain and a touchdown.

In the 3-4, the center often has a nose tackle right in front of him, meaning he has to handle the nose tackle and make sure the guards are blocking the correct linebackers so the play isn’t stopped for a loss.

The center is even more important in the passing game because he has to adjust the protection to the defense’s blitz, often being forced to guess where the pressure is coming from.

For example, if starting center William Vlachos were to see signs of an overload blitz coming on the left side, he would have to communicate with starting left guard Chance Warmack and left tackle Barrett Jones to set up the protection so no defender goes unblocked for an easy sack.

The guards are often the most athletic of the offensive linemen in the running game, required to make pull blocks in counter and toss sweep plays. A pull block is when the guard leaves his gap at the snap and runs around the tackle to the outside to create a seam for the running back to run through.

A more difficult version of the pull block comes through on counter plays, where the guard on the opposite side of the line will run behind the center and serve as a lead blocker for the play, being forced to flip his position on the line before the ball gets to the running back.

In pass protection, the guard is often forced to cover both the A gap (the gap between the center and the guard) because the center is dealing with a nose tackle or a linebacker, and the B gap (the gap between the guard and tackle) because the tackle is handling the defensive end, simultaneously.

The tackle also has a unique set of responsibilities. In the running game, the tackle is the most important block on the stretch play that Alabama uses so much. The running back often runs right at the tackle while receiving the hand-off and cuts away at the last second, which makes the tackle’s ability to hold the block crucial.

In pass protection, the tackle has to deal with an oftentimes much faster defensive end who will try to run around the tackle by taking the edge. The tackle can’t be too quick to step to the edge, though, because that would leave him very vulnerable to a bull rush, where the defensive end charges the tackle and knocks him over while he is off balance.

With so many different techniques and talents required for each position, the possibility of moving around can have an effect on an offensive line, especially in pregame preparations.

“I practice a little bit everywhere,” Jones said.

Jones knows the rigors of the position change all too well. Having started at right guard for 25 of the Tide’s 27 games in the 2009 and 2010 seasons (he was injured for the 2010 Iron Bowl and the Capital One Bowl that followed), he has started at left tackle every game thus far in the 2011 season.

When asked if the possibility of a position change affects makes their job harder, Jones said, “Yes and no. Once you learn the offense, you can play any spot up front. I mean, I have been here for four years and I know the offense really well so I can play anywhere. But at the same time, it looks a little different. It’s hard to describe it. It’s getting your eyes accustomed to seeing things that way.”

Jones is not the first person to endure these changes. In head coach Nick Saban’s first year at Alabama in 2007, the Crimson Tide used seven different combinations of starting offensive linemen, using nine different players and having several start at more than one position.

While the Tide has yet to change the starting rotation this season, the possibility is always there as the rigors of a Southeastern Conference schedule can help one player separate himself as the clear-cut starter or cause injuries, requiring backups to step into starting roles.

One good possibility is that true freshman Cyrus Kouandjio could develop and take over the starting left tackle position, which would move Jones to either left guard or right guard, thus taking Warmack or Anthony Steen out of their starting spot.

“[Kouandjio] is coming along really well,” Jones said. “He’s working really hard and is continuing to study the offense. I’m really proud of how hungry he is and his willingness to learn. There’s no doubt that he has the skills necessary, as you all can see.”

Even with all the difficulties that come with a position change in the offensive line, the right type of athlete can handle it, and Jones is just that.

“It just benefits me having him out there,” running back Trent Richardson said. “Most of the time I tell coach to run the ball to Barrett’s side.”

As SEC play begins with this week’s matchup against the Razorbacks, the offensive line’s performance for each individual and as a unit will become more important.