As good as Brady was at the end, this was nearly all Belichick. Holding an elite modern offense to 3 points, and really only 4 significant drives including the final ‘prevent’ is truly impressive.
In my not-pro opinion, this game would have been a win or the Rams with Cooper Kupp.
He fills a space for LA similar to Welker, Edelman, Hogan, etc. do for the Patriots. These receivers are the go-to on 3rd downs and add a dangerous component defenses can’t ignore. The Rams just didn’t have any threat other than a tough run or a deep receiver, which left them much easier to cover.
That McDaniels/Belichick call in the early 4th where Gronk did the bump-and-go was the game changer! A perfect play for the fastest defense in the league!