Oh we are talking about this year? Looking at the teams that got beat in the 1st round, mostly were fairly obvious on who the winners were gonna be before the games started.
Saints are finally facing a defense, and they are historically not a good road team (hence they never won a playoff game on the road, and score about 20 less points away vs home game, that is were situation/circumstances come into play). If they faced a capable qb other then Smith, they would have been blown out as there defense is far from great. That is why many were picking SF to be the surprise win this week, even though being a higher seed.
You can look at the micro, but I think it can be dangerous. I prefer to look at much more then that, but thats just me.