Betting 101: Gaining an understanding of what the odds actually mean

Plus and minus are basics of math, and sports gambling.

When you fire up your favorite sportsbook app and look up the matches you want to bet, you’ll quickly learn that players are often priced differently. For example, if you’re looking to win $10 on a bet, you’d have to risk more of your money to do that on somebody like 22-time Grand Slam champion Novak Djokovic than a player like Diego Schwartzman. And that’s precisely why Djokovic would be considered the “favorite” in a match against Schwartzman, who then takes the “underdog” tag.

Sticking with the Djokovic-Schwartzman example, you’re going to see some confusing-looking odds if those two meet one another. In a match like that, Djokovic might be listed at -950 to win, while Schwartzman would be +650. Betting somebody at -950 simply means that you’d need to risk $950 in order to win $100—or, $95 to win $10. And going the other way, with Schwartzman, you would be betting $10 to win $65 (or, betting $100 to win $650). The latter is a lot more enticing, which is why bettors are drawn to underdogs.

Let's run through a less lopsided scenario. Using an actual example from the fourth round of the 2023 Australian Open, you might see a match-up between players like Andrey Rublev and Holger Rune, where not much separates the two. Rublev was a +110 underdog in that match, while Rune was listed as the favorite at -135. That means that a $10 bet on Rublev would return $11 dollars, while you would need to put $13.50 on Rune to win $10. Using the same math, you could risk $10 on the Dane to win $7.40.

If you’re still a little confused by what these numbers mean, we encourage you to search online for odds calculators. You can find them all over the place, and they’ll do the hard work for you.

One last thing we’d like to leave you with is that -110 odds on any bet implies a 50% chance of either side winning. So, if Rublev and Rune were both listed at -110 odds, that would mean that the bet is something of a coin flip. As you get further away from that -110 number, you learn more and more about which bet the oddsmakers view as more likely to win.