This is a little historical analysis to shed light on the problem the 49ers have right now. Their problem is no Justin Smith. Without Justin Smith their defense doesn’t seem to be a big deal. In fact, it seems to be a liability. Harbaugh may be responsible for his team losing Smith and here’s how.

Before the New England game, Harbaugh activated Scott Tolzien. It was a strange call. It meant he had three quarterbacks but he didn’t need three QBs. He needed extra defensive linemen. Why? Because the Patriots run a million offensive plays and they run them fast, and D linemen get gassed fast. Harbaugh should have known that. The Niners went up big in the first half. He could have rested Justin Smith, but he couldn’t really rest Smith a lot because he had few defensive linemen — but he did have that extra QB.

Smith got hurt in the third quarter and the defense has not been the same. If Harbaugh had more depth on the D Line it’s possible Smith doesn’t get hurt and the defense doesn’t fold. I’m surprised Harbaugh made such a basic strategic blunder.