# Odds of winning the US Open

Since we are doing a summer project on counting and probability I thought it would be neat to talk a little bit about odds in sports. We decided to look at the odds for a few of the players to win the US Open golf tournament for today’s project.

I grabbed the posted odds from the European sports aggregator site Oddschecker and asked the kids if they understood what the odds meant. I wasn’t expecting them to understand odds completely, but they did have some interesting ideas:

After a brief introduction to odds, we took a quick look at what it meant that Jordan Spieth had odds of 2 to 1 to win today. My youngest son thought these odds meant he would win half of the time. My oldest son was a little confused by how sports betting worked, but I tried to simplify the ideas by just talking about the amount of money you start with and the amount you end with.

After working through Jordan Spieth’s odds of winning, we tried to understand the odds for a few of the other players. Dustin Johnson, for example, had odds of 11 to 4 – a tiny bit harder to understand than 2 to 1.

Now we switched to looking at the odds of finishing in the top 5. One of the nice things about Oddschecker is that you can find odds for lots of unusual bets. The listed odds for Jordan Spieth finishing in the top 5 today were 1 to 5. I wanted to look at this case since the high and low numbers are reversed from the first example that we looked through.

This section went a little long because of a little confusion about what 1/6th is as a percent. I’m not sure where the confusion came from, but we spent the last 4 minutes of the video sorting out how to write 1/6th as a percent.

We started this last section by finishing up the talk about 1/6th and then moved on to talking about both the odds and percentages of the other players finishing in the top 5. Here we encountered some more fractions that we needed to convert to percentages and the work we did on 1/6th seemed to help.

So a fun project that is somewhat related to the summer project that I’m working through with the boys. Hopefully next time they hear about odds they’ll have a little bit better understanding of how they work. Also, I’m happy that we ran across some of the confusion about fractions and percents. It has been a while since I covered percents with them and the struggles today gave me a nice reminder to spend a little time reviewing percents at some point this summer.

## 3 thoughts on “Odds of winning the US Open”

1. Scott says:

I like the estimating but do you guys ever do long division? I guess the only other time long division really comes up is when you’re doing polynomial division.

1. they know how to do it, though I honestly can’t remember the last time it came up in a project.

2. Another good probability topic from sports is mixed strategy equilibrium. Since golf doesn’t have simultaneous moves, you can do this one at the end of the summer for the tennis US Open.