Matthew Stockman/Getty Images Serena Williams hasn't lost in 2015.Some of these athletes are right in their primes, some have a long track record of sustained success, and some are athletes just beginning their dominance.
We recently ranked $4 in general, but we also chose the most dominant in each sport individually.
From the NFL and NBA to soccer, tennis, golf, track and field, and more, we selected the 31 athletes who stake a claim as the best in the world at what they do.