How the odds have changed for the Mayweather vs. McGregor fight

We’re both gonna be rich anyway.
We’re both gonna be rich anyway.
Image: Reuters/Steve Marcus
We may earn a commission from links on this page.

Today (Aug. 26) two men will beat the crap out of each other and a bunch of other (mostly) men will win or lose a lot of money depending on who beat more crap out of whom. But how much they win or lose depends on the betting odds for the fight between Floyd Mayweather and Conor McGregor, which have changed dramatically since they were first recorded.

Mayweather has an inhuman 49-0 record in boxing matches, while McGregor—a mixed martial arts and UFC fighter—has not fought any pure boxing matches professionally. That imbalance has made Mayweather a massive favorite, but since the fight date was announced in June, the odds have tightened.

Here’s a chart showing how the betting odds have changed over time, with the most recent data coming from this morning:

The data come from OddsShark, which tracks bets on Bovada, the most popular betting site in the US.

Those numbers require some explanation of the weird betting odds system used in the United States, called moneylines. The moneyline tells you, basically, how your bet relates to $100. If the moneyline value for an outcome—like the winner of a boxing match—is negative, it tells you how much money you need to put in to win $100. So if it’s -500, a winning $500 bet would make you $100 (i.e., you would walk home with $600 in your pocket). If the value is positive, the number represents how much you will win if you bet $100. If it’s +250, every winning $100 bet gets you $250. So the more negative the moneyline for an outcome, the more likely betting markets think that outcome is.

In November, Mayweather was such a heavy favorite that you’d need to put in $2,250 to win a meager $100, while you could win $950 on a bet of just $100 for a McGregor victory. Today those numbers are $375 and $285, respectively. Most boxing experts don’t think the boxing novice McGregor has much of a chance, so the closer odds are probably more the result of many bettors hoping to make money off of a long-shot than of belief that he is likely to win.

The biggest winners, of course, will be Mayweather and McGregor, who, win or lose, stand to earn hundreds of millions of dollars.