So here's another way of looking at the Bears in SB XX
3 points came off turnovers. On their second play of the game, Walter Payton fumbled and the Pats recovered on the Chicago 19. They had 3 plays for 0 yards and kicked a FG.
Here are NE's drives in the first half
1st drive --> 3 plays, 0 yards, FG
2nd drive --> 3 plays, -10 yards, punt
3rd drive --> 2 plays, -7 yards, fumble
4th drive --> 1 play, -5 yards, fumble
5th drive --> 3 plays, -1 yard, punt
6th drive --> 3 plays, -13 yards, punt
7th drive --> 6 plays, 17 yards, punt
So, in the first half, NE had -19 yards in offense and 1 first down.
Here are NE's drives in the second half
8th drive --> 6 plays, 12 yards, punt
9th drive --> 3 plays, 3 yards, INT returned for a TD
10th drive --> 2 plays, 19 yards, fumble
USATODAY.com - Super Bowl XX play-by-play
By this time, it's 44-3 with 2 minutes to play in the 3rd quarter. NE had 2 first downs, 15 yards in offense and 4 turnovers.
Seattle's defense was good but not that good.
Here is another way to look at it...
Bears held a so-so offense of season 85 to ten points.
Seahawks held the best offense in the history of the NFL to 8 points.