These judgements are mostly based on the number of returning starting linemen.
Returning starter = Started at least seven games in 2010.
I won't count size or recruiting stars but I'll mention it when it presents itself.
So consider the argument that games are won in the trenches.
Sounds right. If the offensive linemen can't block, the quarterback doesn't have the time to throw. Running backs can't run over or evade the front seven, and wide receivers won't have time to run their routes
If the defensive line doesn't rush the passer or stop the run, safeties and corner backs have to cover their receiver until the QB makes a good decision. If running, linebackers are being blocked by offensive linemen who are 50 pounds heavier because they already knocked over the D-line. If pass, rush linebackers are taking blocks that were supposed to be taken up and in coverage they have to keep up with tight ends or running backs for the whole play.
Like all methods, it's not perfect because you always have replacements putting on a show. Returning starters could just continue to be inconsistent or all of a sudden become so.