Floyd Mayweather’s unbeaten record not only has him universally regarded as the best boxer of his generation, but he’s also been involved in the conversation among the top fighters in the history of the sport. As the 38-year-old looks to beat Manny Pacquiao on Saturday and add the biggest victory to his career, Mayweather hasn’t been shy about proclaiming his place in history.

Considering the number of great boxers over the years, it can be argued that Mayweather isn’t even one of the five best fighters to ever step inside the ring. Mayweather, though, calls himself “The Best Ever,” and believes his resume stands up favorably against anyone that’s ever laced up a pair of gloves.

“No one can ever brainwash me to make me believe that Sugar Ray Robinson and Muhammad Ali were better than me,” Mayweather told pundit Stephen A. Smith in a recent interview. “No one could ever brainwash me and tell me that. But one thing I will do, I’m going to take my hat off to them and respect those guys because those are the guys that paved the way for me to be where I’m at today.”

When pressed on the matter of whether or not he’s better than Ali, Mayweather reiterated his belief with the utmost confidence.

“How? [Ali] only fought in one weight class. Leon Spinks beat him when he had seven fights. They’ll never put a fighter in there with Floyd Mayweather with seven fights.

“So you’re going to tell me that it’s cool to lay on the ropes, and take punishment, let a man tire himself out from beating you, and then he’s basically fatigued. You hit him with a few punches and he goes down and quits, and you want to be glorified for that? Absolutely not. Not me.”

Looking strictly at the numbers, Mayweather’s claims don’t appear to be all that bold. In 47 fights, Mayweather has been close to perfect. Having never lost a bout, only three judges have ever failed to score a fight in his favor, including a controversial draw against Canelo Alvarez that led judge C.J. Ross to step down. Mayweather has recorded 26 knockouts, and the only time he was ever officially knocked down he ended up winning the fight handily.

Mayweather is adamant that he’ll retire following his fight in September, and doing so with two wins in 2015 would put his career mark at 49-0. Amassing such a record would equal boxing legend Rocky Marciano, who also went 49 fights without a loss. A win over Pacquiao would give Mayweather victories over essentially every top boxer of his generation. The likes of Shane Mosley, Miguel Cotto and Juan Manuel Marquez were among the best fighters put in front of Mayweather, and he topped them all.

But the level of competition Mayweather has fought throughout his career can’t be overlooked. He certainly has had his share of marquee victories, and beating Pacquiao would add another to the list, but he hasn’t beaten anywhere near the level of competition like some of the best all-time boxers.

Robinson is regarded by many as the best pound-for-pound fighter of all-time. He suffered 19 losses in his career, but his 173 victories and 108 knockouts put him in a different class than Mayweather. With wins against the likes of Henry Armstrong, Sammy Angott, Rocky Graziano, Fritzie Zivic, and Jake LaMotta, Robinson’s resume is second to none. Robinson was also unafraid to fight on foreign soil against strong competition.

Ali might not have been able to bounce around different weight classes like Mayweather, but his dominance as a heavyweight fighter makes him an unquestionable top-five all-time great. Having beaten Joe Frazier and Sonny Liston twice, as well as George Foreman, it’d be difficult to say Ali’s career wasn’t more impressive than Mayweather’s.

It's also highly debatable that Mayweather is in the same class as Joe Louis. "The Brown Bomber" completely dominated the heavyweight division as a champion from 1937-1949. He even had a hiatus from boxing while serving in World War II. Louis owned a 58-1 record before his first retirement in March 1949.

Also included in the conversation of the all-time greats are Armstrong, Jack Johnson, Jack Dempsey, and Willie Pep. Roy Jones Jr., prior to his decision to extend his career into his mid-30s while entertaining a basketball career, was considered among the all-time greats.

Mayweather will certainly improve his standing in the pantheon of all-time great fighters with a win over Pacquiao, who many consider to be the best boxer of the previous decade. There’s no denying his greatness, and continuing to win at multiple weight classes makes him one of the best to ever compete in the sport. Mayweather's victories have also been convincing, winning nearly all of his decision victories on all the judges' scorecards.

But even though the fight is garnering an unprecedented level of mainstream attention, many believe that this fight is five years overdue. A victory over Pacquiao in 2010 would have done more for Mayweather’s legacy than beating a fighter who has two losses in the last three years.