Floyd Mayweather, statistically the most successful boxer in history, concludes his career in Las Vegas this weekend. Or at least we think he will. Boasting 48 consecutive wins, he has promised to bow out when he equals former heavyweight champion Rocky Marciano's record of 49 fights without defeat. But the one thing you can never discount is Mayweather's swollen ego.It casts a shadow over every other superstar of sport.Even though he's 38 and has begun to slow, Mayweather knows that 50-0 has a nicer look to it, particularly with a new arena being built in Sin City.Who else but Las Vegas's most bejewelled resident to open it next year?"I know the end is coming," he recently said, foreshadowing a finish to the longest winning streak - 19 years - in boxing history.The response to his selection of André Berto as his 49th opponent has been largely ambivalent. Berto is old-school tough and will have a crack, but he is no A-lister.The assumption is that Mayweather wants to put an exclamation mark on his final flourish, admittedly a long shot given that his last stoppage win occurred in 2011.Mayweather is a better technician and boxer than Marciano ever was, but Marciano was a fans' fighter, all blood and guts. "The Brockton Blockbuster" relished blood fests and was never in a bad fight.Unlike Larry Holmes, Mayweather has been cautious about entering the great Marciano's orbit.Holmes was 48-0 when he fought Michael Spinks 30 years ago, only to lose both the fight and the chance to equal the long-standing record."Rocky Marciano couldn't carry my jockstrap," said a bitter Holmes. It was a remark the US never forgave him for.Mayweather's genius lies in his technical skills, an under-appreciated talent that will define his legacy.Despite his long career and battles against big hitters like Miguel Cotto, Marcos Maidana and Oscar de la Hoya, his face is handsome and unmarked.He has none of the punchiness that so many older fighters, not least his father and uncle, carry around.No one disputes Mayweather's standing as a great boxer, but his braggadocio is what irks many.But he cares little for the haters; he's been happy to cast himself as the villain. As he boasts, whether you pay to watch him win or you pay to watch him lose, you pay. We'll miss him when he's gone...