Billy,
Home Team Point Spread Power + home field advantage - Away Team Point Spread Power EQUALS the projected line.
Alabama Point Spread Power: 102
Alabama home field: 5
LSU Point Spread Power: 101.5
Project line = Alabama -5.5
With the actual line lower than that, the public is either showing more of a bias for LSU (which would mean value on Alabama) OR there are handicapping factors not built into the power rankings. Your ability to judge that will drive your ability to find value.
Said another way - when the line is off, are you able to define why it is unwarrented? If yes, you got value. If no, then there's likely something about the game you are not seeing.