Hannah played guard and tackle.
There's a problem when it comes to saying how good players are, have been, and where they are listed all time. I'm not talking about different era's of football, I'm talking about how they are judged. This is a prime example.
John Hannah was selected as an All-American twice during his time at Bama. Barrett has the same. Hannah played from 1970 through 1972 and in those three seasons he was part of an SEC Championship team. Barrett has that, plus two National title rings as well.
When you compare college careers to college careers, Barrett has the hardward edge by a large margin.
Now, Coach Bryant called Hannah the best offensive lineman he's ever coached. That praise alone puts him above the majority of great lineman we've had in Tuscaloosa.
BUT, here's the kicker...
When people talk about players coming from Alabama they often mix their time in college with their time in the pro's. Hannah was in the pro bowl nine times. He was talked about in the league for a decade after he left Bama and because of that exposure people consider him to be the best of all time.
For his career? Possibly. In college?
Just to add another twist here. There are many who don't feel Barrett is the best lineman we have.