What the Hell is Pound-For-Pound?

Pound-for-Pound refers to the concept of who the best fighter is when you take size out of the equation.

Let’s take Georges St-Pierre as an example. Pretend that he has moved up in size and weight to light heavyweight. With all his other skills remaining the same, would he be better than other fighters in the light heavyweight class. Would he be better than Rashad Evans or Forrest Griffin? Now move him up in size and weight to heavyweight. With all of his other skills remaining the same would he be better than Brock Lesnar or Frank Mir?

The thing is this is really just a good arguing point for people. There really is no way to ever determine with certainty who the best pound-for-pound fighter is. If you look at lists that people create of the best pound-for-pound fighters there are always differences. It is impossible to be completely objective in the list because there will always be subjective influence.