The 3-4 is at is commonly known places three defensive lineman up front followed by four linebackers, as opposed to the more traditional four defensive lineman and three linebackers. One of the linebackers is typically regarded as the ‘elephant’. The ‘elephant’ is a player who can play up on the line to rush the passer or who can drop effectively back into pass coverage. In Julian Peterson they have someone who could man that elephant position quite effectively too.

So if the 49ers have such talent at linebacker, it would make sense to play the 3-4 wouldn’t? Well not quite. There are several reasons why the 49ers don’t revert to the 3-4 defensive formation. The biggest of which, is likely that they don’t have a player who could play nose tackle effectively on the defensive line. The nose tackle would be the inside lineman and typically needs to be quite big - more importantly though, they must command a double team on virtually every down, otherwise the formation is rendered virtually useless.

Bryant Young could be the nose tackle for the 49ers, if of course he was about fifty pounds heavier. Rather BY would fit quite well into a defensive end position in the 3-4. Dana Stubblefield is still not big enough, but more importantly not good enough to command the double team - and there’s little reason to mention Reggie McGrew.

With little depth behind the top four linebackers - Saleem Rasheed, a rookie may be the best man off the bench, and no true nose tackle, the 49ers have little reason to make the switch. But there are other reasons too. An important one is that the players who they have recently drafted and signed, the likes of Josh Shaw and Sean Moran, are not particularly well suited for the 3-4. Andre Carter could potentially play in an elephant position, but that position would already be held by Peterson, making Carter’s presence on the team slightly redundant.