PFF grade is subjective upon the grader and the PFF guidelines. If you spent the whole game under throwing wide open receivers and he somehow one handed catches it jukes out 10 dudes and gets the TD, your passer rating would be perfect but your PFF grade wouldn’t be. I’m not saying that’s what Purdy did, but just using it to make the example of how the two aren’t correlated.
A QB could miss all his throws and have a horrible passer rating but if his throws were all perfect and the receivers should have caught them, then his PFF grade would be good.
PFF grade is subjective upon the grader and the PFF guidelines. If you spent the whole game under throwing wide open receivers and he somehow one handed catches it jukes out 10 dudes and gets the TD, your passer rating would be perfect but your PFF grade wouldn’t be. I’m not saying that’s what Purdy did, but just using it to make the example of how the two aren’t correlated.
A QB could miss all his throws and have a horrible passer rating but if his throws were all perfect and the receivers should have caught them, then his PFF grade would be good.