re: Why is the SB so often a blowout?

I've had the theory that the conference playoffs is about coaching while the Super Bowl is about physical talent. Whenever a team plays another team in the same conference, they're a lot more familiar with each other so coaching comes more into play. The team with better coaching who knows how to exploit the other team's weaknesses wins more often than not. In the Super Bowl, the teams don't know each other very well at all. After all, they only play once every four years. So in those matchups, any coaching advantage is often negated and the winner of the game is usually the team with more pure physical talent.