Here is an interesting article written in 2018 that I found when I googled NFL Salary Cap Analytics …
https://www. Even putting together two years of success is hard – of the top four teams in 2017’s DVOA rankings, three ranked 20th or worse in 2016, and of the top three in 2016, two fell to 13th or lower in 2017.
In his legendary 1997 tome Finding the Winning Edge, Bill Walsh wrote, “One aspect of the cap that is a major concern for all parties is the disproportionate amount of funds being committed to a smaller and smaller group of players.” He noted that in 1996, NFL teams spent 51 percent of their total cap allotment on their 10 most expensive players.
Another excellent piece here discusses the optimizing the allocation of the salary cap funds.
Based on past results, there was an indication that a more uniform salary structure would be found to be optimal rather than that which currently exists in the NFL. While, in general, it seems that teams with the best quarterbacks are those that win the most, Winsberg indicated that it is not optimal in terms of team performance to have a highly paid quarterback.