According to BetOnline.ag, 86 percent of all bets are on the Irishman for the boxing bout Saturday in Las Vegas. The public's biggest winner for all prop bets offered is +2500 (25-1) for McGregor to win Round 1.
"With four days of action yet to come in it is already the biggest bet fight in the history of BO - exceeding the Mayweather-Pacquaio fight which was huge," sportsbook brand manager for BetOline.ag Dave Mason said. "There are already more bets on McGregor than either the Patriots or Falcons in last year's Super Bowl. About 86% of the bets are on the underdog McGregor."
Mayweather enters the fight with a 49-0 record, making sportsbooks a big fan.
"Fights in general the public just about always backs the big dogs," Mason said. "Public would rather risk a little to win a lot than risk a lot to win a little. We are always Mayweather fans no matter who he fights - the public is always on his opponent. But yea, this trend applies even more to this weekend's fight. Think it's magnified due to all the McGregor hype and popularity. Also people think Mayweather is old now. Plus many people don't think Mayweather is good because he is a defensive boxer and somewhat 'boring' to the public eye; while Conor is a very exciting fighter and KO artist."
Mayweather opened as a -2000 favorite to win the fight. He is now a -465 favorite for the fight.
"Not only is BO exposed on McGregor for the standard odds, but also on just about all the props. Almost every prop associated with McGregor BO is in the red on," Mason said. "And every prop associated with Mayweather BO is in the black. For instance, with four days of action yet to come in, the McGregor to win in the 1st Round is already the biggest exposure BO's ever had on a prop - by far. Currently the liability is already bigger than any MLB game BO lost this season."
Other interesting prop bets include a first-round knockout, with -600 odds for there not being one and +400 for it happening. There is currently -450 odds for no rematch by the end of 2018, +350 odds for a boxing rematch and +2500 odds for an MMA rematch.
There are currently -205 odds of Justin Bieber wearing sunglasses and -200 odds of Lil Wayne wearing a shirt during the walkout. There are +1400 odds for five or more knockdowns during the fight and +200 odds for exactly one knockdown during the session. The odds for Donald Trump tweeting more than 6.5 times on the day of the fight are currently -150. There are +120 odds for fewer than 6.5 tweets from the President on Saturday.
Showtime's pay-per-view for the boxing bout begins at 6 p.m. Saturday. McGregor and Mayweather's matchup is expected to begin sometime before 9 p.m. at T-Mobile Arena.