Floyd Mayweather Jr. Floyd Mayweather Jr. is currently the undefeated professional boxer that has knack for betting on sports. His recent winning was reported to be a $3 million win from a wager on college football. He is also known to regularly bet up to $400,000 per sporting event. His ex-wife even has said that one time she had to drop off $700,000 for him to cover his casino bet, and earlier in January 2014 media reported that Floyd Mayweather may have placed a $10 million bet that the Broncos will win the Super Bowl. In 2017, Conor McGregor mentioned Mayweather’s gambling addiction during their face-off before their fight in Las Vegas.