This might be a great example of why Pro Football Focus' grades and rankings are meant to be taken with a grain of salt.
Most of us love PFF in one form or another. When their analytical grades back up our arguments, we don't hesitate to point that out. When the grades don't, the PFF folks are an easy target for the "you don't know ball" crowd.
But, in some cases, even they seem to admit their grades and ranks don't quite add up.
Such is the case with the San Francisco 49ers and their offensive line through five weeks.