This was a really good analysis. It describes how the Patriots prepared for this game and how they changed things up defensively.
From:
‘The best to ever do it’: How Bill Belichick outcoached Sean McVay in the Super Bowl
...Patriots players knew to expect two weeks of intensive study. Belichick does not use a set system. He has a basic set of fundamental tenets, but he alters strategy weekly based on his opponent’s features and flaws.
“We switch every week,” Patriots safety Devin McCourtney said in the locker room after the game. “We don’t just do something because that’s what we do.”
In the next locker over, his brother Jason, a Patriots cornerback, overheard him and asked, “How about Kansas City vs. this game plan?”
“Totally different,” Devin said.
Belichick unveiled his defensive game plan to his team early during the off week. Belichick and his staff had deduced that the Rams specialized in “man beaters,” Boyer said — tactics meant to defeat man coverage. Their litany of shifts, bunched formations, and frequent jet motion all thrive against man coverage, which is the style the Patriots played almost all season, and what they used extensively in Kansas City.
Against the Rams, though, the Patriots would start the game in zone coverage. The Patriots believed it would limit the effectiveness of how McVay dresses up his simple-yet-deadly scheme, and that it would stagger Goff, a 24-year-old facing Belichick for the first time.
“Our philosophy is always, we’re going to give them something a little bit different,” Boyer said. “Try to get good pressure up the middle and force Goff into some throws deep and try to have it protected deep.”
The Patriots added a wrinkle within the wrinkle. Halfway through the first week of preparation, coaches switched Jonathan Jones’s primary role from cornerback to safety. Jones, an undrafted free agent the Patriots picked up out of Auburn in 2016, has toggled between the positions all season, and his versatility is one reason the Patriots value him....
...
All year, Jones had frequently blitzed as either an outside corner or a nickelback. When he crept close to the line, Goff would assume he might blitz. Then he would drop back — not to a corner’s position, but to the center of the field, where he was responsible for a deep quarter of New England’s coverage. When Goff audibled, Boyer said, the Patriots could change their defensive call simply by moving around Jones.
“Early on,” Goff said, “they were able to keep us completely guessing.”
The Patriots also devised exotic pass rushes from an alignment meant to stifle the run and force Goff to beat them. The Patriots walked up two linebackers to the line of scrimmage, effectively employing a six-man defensive line. The alignment clogged running lanes on early downs. When the Rams passed, the Patriots would vary which defenders rushed and which dropped into coverage, frequently using pass-rush combinations they had never shown....
Lots more in the whole article about their strategy and why it worked. Well-worth a read.
