By Edward Chaykovsky

WBC/WBA welterweight champion Floyd Mayweather Jr. (48-0, 26KOs) raised some eyebrows when he appeared on ESPN Deportes and ranked himself as the best fighter of all-time.

Mayweather, who refers to himself as 'The Best Ever' - will enter the ring on September 12th for what he promises to be the final time of his pro career. He will defend his world titles against former two-time beltholder Andre Berto at the MGM Grand in Las Vegas. The bout will be carried by Showtime Pay-Per-View.

Showtime analyst Steve Farhood says he would rank Mayweather somewhere between number 10 and number 15 of all-time.

"It means a lot to Floyd to be considered the best ever, so maybe that’s why he ranked Ali so low. The mistake he makes is you don’t judge Ali or Sugar Ray Robinson past their primes. Same with Roy Jones," Farhood told CBS Sports.

"It’s not up to Floyd to rate where he belongs. It’s up to writers and historians. My reaction is this – it’s really almost unfair to rate today’s fighters vs 70 years ago. Robinson fought Jake LaMotta twice in three weeks. Floyd would never fight Manny Pacquiao twice in three weeks."

"I studied different generations, and found that with each succeeding era fighters fought exponentially less. There are a number of reasons for that, one of which is they make more money today and don’t need to fight every month. Starting with the Joe Louis era, the average fights per year drops by one. and now you’ve got Floyd fighting twice per year. Including heavyweights, you have your Leonards, Durans, and Ali and Louis. I’d put Floyd between top ten and 15 all time. It may not sound great, but it is. And he is."

And how would Mayweather match up against the Four Kings - Robert Duran, Sugar Ray Leonard, Marvin Hagler and Thomas Hearns?

"Mayweather is the best of his era and would have fit in well in any era. A lot of people would kill me for this, but I think Mayweather would have had a great chance against Duran – but at welterweight, not lightweight. But I think Thomas Hearns and Ray Leonard were too big and strong for Floyd. Hagler was naturally too big. Not a fair fight," Farhood said.