There isn’t a ton of data here with Dak Prescott only playing in the NFL for a little over 3 seasons, but it is interesting to see that despite his worst adjusted net yards per attempt, he still had a an ESPN QBR of nearly 70 in 2017, despite what most would say was his worst season overall.
Efficiency can be measured in different ways, but ANY/A should provide a good barometer for how efficient a quarterback is on a snap-to-snap basis. However, one could reasonably expect ESPN’s rating system for quarterbacks look similar from an efficiency standpoint. So, as one’s eyes move right in the chart, the dots should continuously rise toward the top, instead of being scattershot as they are. One could expect the correlation to be even tighter with a quarterback who never used his legs as a weapon, like Manning.
Again, and possibly even more evidently, there seems to be absolutely no correlation between ANY/A and ESPN’s QBR. Some of Brady’s highest QBR years were under his median ANY/A years.