Good post. What I think that the system really doesn't really account for is coaching acumen in close games (and there are always a lot of close games -- just ask Belichick). A really good team can dominate most games and still go 8-8. I don't think that who wins close games in the aggregate comes down to a series of coin flips (in the probabilistic sense). For instance, the 2017 Bills were a bad team talent wise and still went 9-7 because they were situationally good in a lot of close games whi