As we neared the end of the development of QBR, we talked to Ron Jaworski and Greg Cosell at NFL Films about its evolution. Cosell said at one point, “Football is not complex, but it is very detailed.” I realized then that QBR is like that. It is very detailed, accounting for a lot of different situations, but it is not particularly complex. It really does try to see the game the way we have gotten used to seeing it in its elegant simplicity. We hope you, the fan, appreciate it, as well.via Explaining the statistics behind the Total Quarterback Rating – ESPN.