If the Pats (Collins in particular) are healthy, apart from fluky stuff I don't see many scenarios where Denver wins.
That's the way I look at games...what is the range of outcomes? Brady, Gronk and Edelman are playing...Pats score in the 20s at least. So, can Denver score in the 20s? That's their maximum upside.
So...the Pats could win a blowout, or win a close one. There's a really wide spectrum of different ways the Pats can win--if this game happens 10 times, the Pats win 9. Denver can't blow the Pats out. They need everything to go their way--turnovers, etc.--while hoping the Pats aren't healthy. Even then, they have to hope for that 1 out of 10 game to happen...the scenario the Broncos win is something like 24-23.
Me, I'll take the 90% odds. Hell, that might be conservative.