No matter how you feel about the spectacle that was the Conor McGregor-Floyd Maywather fight, you have to admit that McGregor performed better than most expected.

But not from the Vegas books' perspective.

Before the fight, the over/under for the length of the fight was set at 9.5 rounds. Since Mayweather won by TKO in the 10th round, anyone who bet the under took home money on Saturday night. One of those people could have been Mayweather himself were it not for some confusion and a delay at the sportsbook. According to ESPN's David Purdum, Mayweather tried to place a $400,000 bet on himself before the fight.

Multiple sources told ESPN that Mayweather went into the sportsbook at the M Resort around 3:30 p.m. PT, Saturday, with cash and plans to bet on his fight against UFC star Conor McGregor.  

Mayweather attempted to place a $400,000 bet on the fight ending under 9.5 rounds at -200 odds, but, according to a source, there were concerns over the legality of a fighter betting on anything other than a straight win, which caused a delay.  

According to the report, Mayweather also wanted to place a bet on himself to win by knockout but grew tired of waiting and left without placing any bets. By the way, the Nevada State Athletic Commission and Nevada Gaming Control have no regulations prohibiting fighters from betting on themselves.

But that doesn't necessarily mean that Mayweather came away without winning any wagers. After the fight, he spoke with ESPN's Sal Paolantonio on SportCenter and said he thinks a friend wound up putting six figures on the under for him.

"I think that we bet 100 on 9.5," Mayweather said. "I gave my guy six figures to go bet. I have to make sure he bet because earlier today I went to the sportsbook to bet and they wouldn't let me bet."

Mayweather has a sweet spot for gambling, but even if his guy forgot to make the bet, he'll probably be OK. He told Jimmy Kimmel last week that he expected to make $350 million for the fight.