I think a big key for Denver, both in this game and the season, was 33-year-old Demarcus Ware fighting back father time. Von Miller is a given as an elite pass rusher, but I thought Ware was close to cooked after he left Dallas, yet he resurrected his game this year. That gave Denver not one, but two elite edge rushers to compliment their better-than-average secondary (I think their linebackers were "meh"). Not many o-lines have two tackles that can handle that.
This why I like BB seemingly emphasizing the pass rush this past year-plus, with Sheard, Easley, Brown, Grissom, Flowers,... Consistent pressure on the quarterback - any quarterback - seems to be a game changer.
But yeah, I think Ware staying healthy and productive was a big component to Denver's defense this year. Malik Jackson turned out to be a player, too.