re: "They have an LSU defense"

Well when you run an offense as Vanilla as LSU ran for the last 11 years you can stack the line with 7 to 8 guys and stop anybody's ground game. Hell, you could scheme against LSU's offense under Miles with video from 8 years ago because nothing changed. Ever. It is much harder to scheme against the unpredictable. The point is that it wasn't a personell problem as much as it was the offense and play design. That has all changed now.

Alabama knows they have to beat LSU every year to reach the goals they have.
LSU knows they have to beat Bamma every year to reach the goals they have.

There isn't a more important game to both of those teams than that one, and everyone knows it on both sides, but will never say it. As others have said, past Bama players talking about LSU, the bye week all show how important the game is to bama, and if you haven't noticed, Bama players and Saban usually rejoice very openly when the clock hits zero and they beat us, which is not something you see them do with other teams.

Both teams know they can lose a game during the season and still reach their goals, but if that loss comes in the LSU/Bama game, the losers goals have pretty much been shattered, except if it's 2011.