To me, there are two primary types of runners in the NFL: Bruisers and Dodgers.
Bruisers are what you would expect them to be—powerful runners that run through defenders, not around them.
Dodgers come in a variety of forms—guys with blazing speed, agile runners that juke out their opponents, smaller guys that manipulate their body in such a way that makes it difficult for defenders to hit them squarely—but they generally find ways to run around defenders, not through them.
Thus, we will attempt to classify the following players into the two following orders, offering a sub-order for each as well. These are the hardest running backs to tackle in NFL history.