Okay, so yesterday I was messing around trying to figure out the odds for the Gauff vs. Navarro match. Thought I’d share how I went about it. No guarantees I got it all right, but hey, that’s the fun of it, right?
First thing I did was hit up a bunch of different sports betting sites. Just googled “gauff vs navarro odds” and clicked on like the first five that popped up. Wanted to see if there was any major difference in what they were offering.
Why so many sites? Well, different sites can have slightly different odds, and even a small difference can matter if you’re actually betting (which I wasn’t, just curious). Plus, sometimes you get signup bonuses and stuff. But mostly, I just wanted a sense of the overall market.
So, I copied down the odds from each site into a little spreadsheet. Just the basic stuff: who they favored, what the moneyline odds were for each player. Some sites had a bunch of extra stuff like game handicaps and over/unders, but I ignored that for now. Just wanted the core stuff.
Then, I started comparing. Found that most sites had Gauff as the clear favorite, which wasn’t a huge surprise. Navarro is good, but Gauff is, well, Gauff. But the actual numbers varied a bit. Some had Gauff at like -200 (meaning you’d have to bet $200 to win $100), while others had her closer to -250. Navarro’s odds were all over the place too, from +150 to almost +200.
- Moneyline: This is the simplest type of bet, just picking who wins.
- Negative odds (like -200): Means that’s how much you need to bet to win $100.
- Positive odds (like +150): Means you win $150 for every $100 you bet.
Next, I tried to figure out what those odds actually meant in terms of implied probability. There are calculators online that do this for you, but I wanted to do it myself just to understand it better. The formula is pretty simple:
If odds are negative: Probability = (-odds) / (-odds + 100)
If odds are positive: Probability = 100 / (odds + 100)
So, if Gauff was at -200, that’s (-200) / (-200 + 100) = 200 / 300 = 0.6667, or about 66.7% chance of winning, according to that site. For Navarro at +150, it’s 100 / (150 + 100) = 100 / 250 = 0.4, or 40%.
But here’s the thing: those probabilities don’t add up to 100%! They add up to more, because the sportsbooks build in a “vig” or “juice” to make a profit. It’s their cut.
To get a more realistic estimate, you have to normalize the probabilities so they add up to 100%. Easiest way to do that is to divide each probability by the sum of all the probabilities. Gets kinda messy, but there are plenty of online calculators if you just want the numbers.
After doing all that, I had a decent idea of what the “market” thought about the match. Basically, Gauff was heavily favored, but there was still a decent chance Navarro could pull off an upset.
Was it worth it? Probably not, if I was actually trying to make money. But I learned a bit about how odds work, and it was a fun way to kill an hour. Maybe next time I’ll try to build my own model to predict the outcome. But that’s a project for another day.
