Here's how I take PFF.
On grades or ranks: I never take it strictly. It's too random and subjective to be taken strictly. But they usually appear to me to be ballpark. Is player x the 22nd ranked corner in the league? 15th? 24th? Ballpark--they're 2nd tier.
Also. PFF is not the only game in town. I think that the way to do subjective evaluation stats is to compare different sources and see what the range is.
And you look at what they evaluate, which came up in this thread. With CBs they only count when they are targeted. Okay so that's never going to give us an accurate picture of what Ramsey is worth to the defense.
...
