Who is the world's best fighter, regardless of weight class? Check out ESPN's top 10, which saw Floyd Mayweather Jr. become a unanimous choice for the top spot after dismantling Canelo Alvarez on Saturday. If you have a comment about the rankings, please use #ESPNP4P on Twitter.
Don't forget to check out Dan Rafael's divisional rankings, which are updated weekly.
For a list of the current champions in all weight classes, click here.
Note: Results are through September 16.