It's an odd stat, less is always more with the passer rating but maybe it shouldn't always be. Below are 2 wide receiver stats with a PR attached to them, everything equal, including catch% except rec/target totals.
A. 4 rec 5 targets 100yds 2tds = 158.33
B. 8 rec 10 targets 100yds 2tds = 147.92
Who had the better game? The qbr says player A, but depending on the game it could be player B. Player B helped control the clock with 8 rec equaling 6 minutes of playing time, player A only 3 minutes. If you needed quick scoring it could be A, controlling the clock B.
I find these qbrs from SB's interesting(pit vs Ram Pats vs Hawks)
Bradshaw
14 of 21 309yds 2 tds 3ints 101.9 PR
Brady
37 of 50 328yds 4tds 2ints 101.1 PR
Passer rating says Bradshaw was slightly better with 2 less tds, 1 more int and 19 less yds.
If you were just looking at the numbers without watching the game and no PR attached to them you'd assume Brady had the better game. If we add time to the equation that would be 37 completions equaling nearly 28 minutes of game time compared to 14 completion, 10.5 minutes.
Below are 3 more from SB's
Bradshaw
9 of 14 96yds 1td 108.0 PR
Montana
14 of 22 157yds 1td 100 PR
Brady
16 of 27 145yds 1td 86.2 PR
IMO you always have to watch the games to know who had the best performance, but just looking at the numbers I'd go Montana, Brady then Bradshaw.
I always play around with it during the season but don't put much stock in it, there's so much context left out. Mahomes not scoring in the 1st half of the AFCCG with a stacked offense at home, missing a layup TD and getting sacked out of FG range will never show up in his passer rating(117 PR and Brady around 77). And I think TB outplayed him personally but PR says Mahomes was in another stratosphere.
I also don't like it because some teams are stacked while others are just average at the skill positions. So comparing Mayfield's numbers to Mahomes is just futile. Or early Mannings numbers throwing to a bunch of 1st rounders to TB's numbers or even TB's numbers compared to guys throwing to complete nobodies. There's also outdoor vs indoor, home vs road, strength of schedule, Oline play, injuries, bad weather etc...