I've noticed this not just on fan forums, but by sports writers as well. Anytime a discussion comes up about how good is this player? Or which of these players is better? Or Who would be an upgrade at this position? At some point, someone is going to quote, or source PFF's grading system. Almost seems like it is becoming the standard. PFF themselves say agents and scouts reference their grading system. I myself really love reading their articles, but of course I don't always agree with their evaluation. Anyone else regularly read pff?
I think they are a good source for "sabery" football stats that go a little deeper than traditional stats, and in many cases they can give you a better, more accurate, idea of a players or a units true value than conventional wisdom and stats will. However, it's not an exact science and definitely not a 100% accurate representation of a players value, although they have improved it greatly over the last few years. Every now and then they throw something out like this that is really facepalm worthy. https://www.profootballfocus.com/blog/2011/03/14/secret-superstar-chilo-rachal-san-francisco-49ers/ Oh, and everything they do, FootballOutsiders did first, and in many ways better, ages ago.
I used to love FO's CB meterics Honestly PFF is too convoluted for me. One thing FO was superior to them was how clearly understandable there metrics were Sent from my HTC Vivid