Before reading this keep in mind, I am a huge broncos fan so this may be slightly biased, but I will give mainly only facts to support my prediction.
Now, why this game is such a big deal:
As far as I know, out of all the Super Bowls since the 1970 merger from the AFL, only six times now has the number one defense played the number one offense. This being the sixth time. Now, let's take a look at how those games went.
4 out of the 5 times has the number defense won, but they have been particularly close games, but the one game different the 49ers and Joe Montana blew out the broncos 55-10. What does this say? Well mainly people compare Montana and Manning, even against a number one defense, Manning is coming off the best year any quarterback has ever had, statistically. His offense put up more points than any other offense despite numerous injuries. I don't think there is any team that can stop this offense.
Broncos Wide recievers vs Seattle Secondary
Now this is the big question, can the broncos get open versus the mean, physical, and stout Seattle secondary? Yes. Let me tell you why, Seattle likes to play man press versus your wide outs, and they are phenomenal at it, so let's say that Byron Maxwell and Richard Sherman take away Decker and Demarius Thomas, so that leaves Wes Weller versus Walter Thurmond and Kam Chancellor or Irvin vs Julius Thomas. Walter Thurmond is a good nickelback corner, don't get me wrong, but Wes Welker is the BEST slot in the game right now, and I think he wins this matchup, leading him to have atleast a 70 yard game and a touchdown. Now Thomas vs Chancellor. Julius Thomas is 6' 5 and weighs 260 pounds, but runs a 4.6 40. Let's put that into perspective, I played wideout and quarterback in highschool, weighing 190 and was 6'3 and was scouted to play at quite a few colleges, and I ran a 4.67, this guy is a tank and he can run. I don't think anyone in the NFL can cover him 1 on 1 in the TE position. I give Thomas 120 yards with 1 touchdowns, at least.
Now, overall I think Peyton will throw 350 yards and 3tds no picks. Why? I think Seattle has yet to play a great passer team and has given up points to simple teams like the Cardinals and Bucaneers whom are not good offenses and this defense can get burned. Now let's talk about matchups on the other side of the ball.
Seattle offense vs Broncos Defense
Let's first talk about Marshawn Lynch, he's a truck, no doubt about it, and in order to stop this offense you must stop Marshawn. Let's talk about why Denver can do that. First off, Pot Roast Terrence Knighton is coming off a terrific game where he displayed why he can control the middle of the line of scrimmage. Now if, he manhandles the center and guard this leaves a free-roaming backer to enjoy his time finding Marshawn. If I was Denver I would keep an eye on zone reads all day and play spy with linebackers, also I believe that Denver will bring an 8th man in the box, who will most likely be Safety Duke Ihenacho to help stop the run. If the broncos can keep Marshawn from having a field day, I suspect this to take a lot of pressure off the Denver secondary, which is mediocre at best.
Now, another aspect, Chris Harris is injured along with Von Miller, two of Denver's best defensive players. But that has yet to stop them. I find that besides Percy Harvin the Seattle recievers are not all that great, and keeping Russel Wilson in the pocket to where he can't run around and extend plays, makes this offense even more one dimensional. I think Denver can do this, and if they do you can bet Seattle won't score more than 17 points.
Score prediction: Broncos 30-24
Please comment if you have any questions and I'll explain things more. This is just a slight over view of how things more than likely will go down.