OK.. if we're going to do this we have to do it at least halfway right. That is, we HAVE to adjust for era, otherwise the era alone will bias everything. So.. let's start with Brady data. I plotted on the x-axis each 2017-adjusted passer rating he had in regular season games he started and on the y-axis the win% for all games with that adjusted passer rating or lower. So.. it turns out 85 is almost exactly at 50% for Brady. So what do we compare that to? Here's the 2017-adjusted passer rating vs. win% from 2002-2017. The average number of wins for 2017-adjusted passer rating 85 or below is 6.2231 wins or 38.9% win%. So Brady is clearly well above that. Obviously, this includes the effect of the defense, coach AND Brady, but these graphs are consistent with Brady increasing win%.