What happened to the 9'er's Defense the last four weeks?

They went from playing the San Diego Chargers, Chicago Bears, McNabb Eagles, and Kansas City Chiefs to playing the Minnesota Vikings, Detroit Lions, and Hasselback/Alexander-less Seahawks.

Great explanation....I'm not concerned about the Offense facing the Niners D. We know the Saints O can move the ball and score on any D. I'm more interested in how the Defense will do versus the Niners Offense. The Saints D has taken the best punches from every team since the bye. The Ravens, Steelers, and Bengals all had one of their best offensive days versus the Saints. How will they react against an O ranked in the twenties? Hopefully they have a "statement" game showing they are good Defense peaking going into the playoffs