Our topic is the Sociology of the Offensive Line. Our guest lecturer is Barrett Jones, the Alabama redshirt junior, a two-time Academic All-American and an All-SEC right guard in 2010. Jones is uniquely qualified to address this topic. In the No. 3 Crimson Tide's 48-7 victory over Kent State to open the season, Jones started at left tackle and moved to left guard. That's unusual but not unheard of.
However, Jones then moved to center for several series in the second half. He played all three positions on the offensive line in one game, none of them on the side of the ball he played for the last two seasons. For offensive linemen, this is the equivalent of playing all nine positions on the baseball field, something only four players have done in the history of major league baseball.
Jones expects to play all three positions again Saturday, when Alabama plays at No. 23 Penn State.
Jones moved from right guard to left tackle this season because he is Alabama's most talented offensive lineman and, at 6-foot-5, 311 pounds, has the size to handle the job. However, Jones likely will play left tackle only until freshman Cyrus Kouandjio is ready to take over.
"I started out at left tackle for the majority of the first half," Jones said of the victory over the Golden Flashes. "And then I moved to guard for just a few series so that I could play beside Cyrus Kouandjio when he first went in, so his first couple of series I could kind of guide him along there.
"And then, after that, I moved to center so I could get some experience there in case, heaven forbid, William [Vlachos] would go down."
Vlachos is a senior and, like Jones, a three-year starter. All of which brings us to the topic of today's lecture.
"They are all really different," Jones said of the three positions. "There are similarities in some ways between guard and tackle, and there are some similarities between guard and center. But I think tackle and center are pretty much totally different."
There are the demands of each positions.
"From a pass-blocking standpoint, tackle is definitely the most difficult," Jones said. "It's just pretty tough to be out there on the edge and to know which sets you have to take and when, because you're blocking guys with speed and power. Sometimes you're blocking corners and linebackers and all kinds of different people off the edge.
"I think center is more of a challenge mentally because you've got to know all the calls and tell everyone on the line where they [should be]," Jones said. "And then, also, snapping the ball is just such an added thing. Centers make it look so easy. And I'm sure it is to somebody who has played there a long time. But it really isn't as easy as it looks to snap the ball and then block somebody, especially when you haven't done it for a long time."
Or ever. Jones' only experience at center prior to Saturday came in the Army All-American Game in January 2008.
The guard lines up between the toughest position physically and the toughest position mentally. That makes him the diplomat of the offensive line, friend to all.
"If you've played guard, you kind of know what the tackle does because a lot of times you're communicating with him," Jones said. "If you've played tackle, a lot of times you have no idea what the center's doing in there . The tackles are always wanting the guards to come out there and help them in pass protection. The centers are always wanting the guards to stay in tight and help them. It's always a constant battle. Everybody wants your help at guard. You're kind of the bridge between the positions."
And now, as promised, the sociology: Now that Jones has played all three positions, he can explain what each position thinks of the other.
"Tackles just think their position is by far the hardest," Jones said. "All the other positions are relatively easy. That's the mindset they have, just because it is very challenging in the passing game, more so than the other two [positions]. The tackles sometimes think they are the most important people on the line. You kind of have to keep an eye on them, keep them humble. I think it all stems from the NFL. The tackles get paid the big bucks. I think that's where it all comes from.
"Centers think they are definitely the smartest. If you ever question one of their calls, they get a little uptight. They take great pride in their calls. They think they know it better than anybody else."
Turns out, they do.
"Playing center gave me a better understanding of how difficult it is to diagnose what's going on and make all the calls. I told William, 'It's much easier to correct your calls than it is to make calls.' I think I have a new respect for what he does."
In the third quarter Saturday, with the Alabama defense on the field, Jones got the word: next possession, he would go in as center. A bad punt snap gave the Crimson Tide the ball at the Kent State 1. That's like dropping a novice skier at the top of a black diamond slope.
"I go right in," Jones said, laughing. "Obviously, the goal line is one of the hardest spots for a center, because you have two guys right on you and you have to snap the ball and block."
By delivering the ball safely, which tailback Eddie Lacy took for the touchdown, Jones delivered Vlachos from a tongue-lashing. Head coach Nick Saban expected Vlachos to recognize that he should return to the field for goal-line offense.
"So I ran out there and did it," Jones said, "and I got back, and Coach Saban pulled me over and said, 'Man, you just saved Vlachos right there because I was going to kill him if you had fumbled that snap.'"
Ivan Maisel is a senior writer for ESPN.com and hosts the ESPNU College Football podcast. Send your questions and comments to him at Ivan.Maisel@ESPN.com.