The regular QB passer rating is a joke but mainly because it has one huge flaw, it doesn't penalize at all for taking sacks, and other lesser flaws like getting lots of yards does not help. Rob Johnson singlehandedly exposed the regular system by being by far the most sackable QB in NFL history while putting up nice to exellnt passer ratings. He finished his career 83.6 passér rating nearly identical to jim Kelly's 84.4. They just need to tweak the current passer rating so sack avoidance and yards count, not trash the whole system.