It was not one versus two TE's. It was WHO was in at TE.
Here is a link to how Belichick shut down the Rams.
https://ftw.usatoday.com/2019/02/super-bowl-53-bill-belichick-gameplan-genius
If you don't want to bother reading the whole thing here is the part about the TE's. They were far better prepared and obviously scoured film looking for something. And they found it. I bolded the critical parts.
4. Attention to detail: Sean McVay’s tell
One of the hardest aspects of defending the Rams offense is discerning the run from the pass.
“They do a lot of things to give the defense problems.”
Belichick said of the Rams offense in the lead-up to the game. “Misdirection and complementary plays so they all kind of look the same but it could be one of two or three things.”
Because of that uniformity, it’s hard to get a read on McVay’s play-calling tendencies, but it appears Belichick was able to find one, and he tailored his defensive personnel groupings based on the intel.
Personnel-wise, New England did what any other defense would have done against the Rams: It matched the Rams’ 11-personnel sets (one running back, one tight end and three receivers) with its nickel package (five defensive backs).
But L.A. has two different 11-personnel sets; one with Tyler Higbee at tight end and one with Gerald Everett. And that’s where you’ll find McVay’s tell. The Rams lined up in 11-personnel with Everett on the field 273 times during the regular season (not including garbage-time snaps), per NFL GSIS. They ran only 37 times. That’s only 14 percent of the time.
So what did Belichick do? When Higbee was on the field, he matched the Rams with the run-stuffing 4-3 front and played that three-level coverage we’ve already covered.
When Everett was the lone tight end on the field, Belichick played his nickel fronts with man coverage on the backend. With Higbee on the field, the Pats had to be mindful of the run; with Everett out there, they could focus solely on stopping the pass. And that’s what they did. The Patriots completely shut down the Rams passing game out of those three-receiver sets. Jared Goff averaged just 5.6 yards per attempt on those passes.
Other coaches may have treated every 11-personnel grouping the same. Not Belichick. He recognized the different threats posed by the Rams’ two tight ends, figured out the tendency and planned accordingly.
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