Question: What is the ranking system used in combat sports, including boxing and mixed martial arts, of who the better fighters are relative to their weight, by which measure the Polish mixed martial artist Joanna Jędrzejczyk is rated the number 1 female MMA fighter in the world?
Sentence (from "Pound for pound"): They may be based on a range of criteria including "quality of opposition", factors such as how exciting the fighter is or how famous they are, or be an attempt to determine who would win if all those ranked were the same size.
Relevant evidence: No