The biggest bet to date has been placed on the huge Las Vegas bout between Conor McGregor and Floyd Mayweather.In fact, it was so large, the casino sportsbook system couldn't process it in one go.The astronomical figure of $880,000 was placed by an anonymous tipster, and due to a system payout limit of $1 million, the bet had to be split into two separate $440,000 tickets.The overall profit is believed to be a cool $160,000 should Mayweather prevail.Mayweather is the clear bookies favourite for the August 26 superfight, and the captivating success that the Irishman McGregor has enjoyed in his MMA career has ensured that this is one of the most eagerly anticipated fights in years.That said, according to comments from the assistant manager Jeff Stoneback of the MGM Grand, fans are seeing real value in the “Notorious” underdog.For every one bet that punters placed on “Money” Mayweather to take the expected win, staggeringly 27 are being placed on the UFC star to orchestrate the biggest upset that boxing, and possibly combat sports as a whole, has ever seen.It is likely that fans are latching onto the Irishman's unwavering confidence.The fight has been the subject of strong criticism from several sections of the boxing community, with many feeling that it is damaging to the sport's reputation to have an undefeated champion with a 49-0 record face up to someone who has never competed in a professional boxing match before.Conor clearly doesn't agree, declaring that after the fight he will be a “God of boxing”."The critics say that Floyd has been there before. They discredit my training, my skills, my accomplishments."This isn't new to me, though, just like boxing isn't new to me. I am no stranger to being the underdog on paper. I am a seasoned veteran and I am confident that I am the better man."After Saturday August 26, I will be a god of boxing."Whoever you're backing, the bank holiday match up will be an intriguing spectacle between two huge personalities.Many will be likely to have a flutter, but the $880,000 gambler will likely be a lot more nervous than most!You can see the man's betting slip below.