It’s a well know theory that a running back gets stronger towards the end of the game. This is usually because the defense gets slower, and so alternating the backs should really make Hearst and Barlow that much better when they do get the ball later in the game. What isn’t taken into account here, is that one of the reasons the running back appears stronger is also that he has had an opportunity to set up the defense for certain moves he’ll use later in the game. It works the same with nearly every position on the field - and by limiting the caries of the backs, it limits their ability to set up the defense for such situations.

The other issue arises is that sometimes neither back is having success with the limited carries, yet the 49ers continue to alternate them. The team should not worry about giving one back 20 caries and the other 10, or even a greater differential if one is producing better than the other. On the same note, if one is doing a better job receiving or pass blocking the team should not insist on using the other back in those situations just because it’s his turn in the rotation.