# There’s a one in five chance…

When the big little clown was in fourth grade, he and his friends were really into Texas Hold’em. I regularly hosted a bunch of nine year olds for poker sessions. They couldn’t get enough of it. The Little Clown and I used to play all the time, even when his friends weren’t around.

Nine year old poker players are pretty easy to beat because they tend to be very aggressive, betting on all kinds of crazy hands. After The Little Clown went all in with three cards to a straight for the umpteenth time I decided it was time for a lesson in probability. As synchronicity would have it, The Little Clown’s annual science fair was coming up and we agreed that he would choose as his question:

What should I bet if I draw three cards to a straight in Texas Hold’em?

We filled in the forms and it didn’t take long before his teacher contacted me, appalled that a nine year old would be playing poker, let alone that he would have the audacity to want to study the topic in a science project. After some negotiation, we compromised on a less provocative hypothesis:

What is the probability of getting a pair if you draw two random cards from a deck?

Little Clown did a science project every year from kindergarden to fifth grade but this one was my favourite as it fulfilled all of my criteria for a good science project.

1. There should be an obvious hypothesis that is wrong.
2. The hypothesis can easily be proved wrong by an experiment.
3. The experimental result can easily be confirmed with maths.

Excuse me for a second while I rant a little about elementary school science projects.

Who exactly was it that decided that filling a cardboard volcano with baking soda and vinegar was a good science project? What is the child learning from the experiment?  What is the hypothesis? How come the vast majority of children’s science projects are either variants on the volcano “experiment” or an exercise in building a model out of lollipop sticks and elastic bands?

I predict that if I leave bread out for three months it will go moldy.

I predict that if I make a little car that is jet-propelled by a balloon, the car will be jet-propelled by the balloon.

How is that science? Where is the experiment?

Anyhoo…

The poker experiment is perfect because 9 years olds (like most people) don’t really get probability and will always get the answer wrong (that’s why they are easy to beat at poker). It’s also easy to demonstrate by choosing random pairs of cards from a deck and recording the results. The maths is a bit harder, but this was actually my favourite bit of maths instruction ever with my budding scientist. We started with a coin.

What is the chance of getting heads if you flip a coin?

We tried it a hundred times and confirmed our intuitions before moving on to something more complex.

What are the chances of getting two heads if you flip two coins?

This was a little bit harder but we figured it out and experiments again confirmed our intuition. We tried more coins.

What are the chances of getting three heads if you flip three coins?

Intuition failed us here but … maths to the rescue! Do 9 years olds know about exponents? *shrug* Mine did and we got the results quickly and confirmed it with experiments. From there, it was trivial to try four coins and five coins so we moved on to dice.

What are the chances of getting a six if you roll a dice?

Intuition was inadequate again, but again the maths held up (hooray, maths!). Exponents still work if the base is 6 instead of 2 and the experiment confirmed it.

What are the chances of getting two sixes if you roll two dice?

By now it was easy and we zoomed through three dice and four dice. Time for cards.

What are the chances of getting a pair if your draw two cards from a deck?

A deck of cards is trickier because you have to deal with the whole take-one-away thing but, luckily, 51 is divisible by 3 and the maths is not hard, even for a nine year old. The experiments are more tedious because you have to deal a lot of pairs to demonstrate a 1 in 17 chance and nine year olds are not famous for their patience. Fortunately my nine year old was already a pretty good Logo programmer as he was already a four year veteran of the business having started to learn Logo in first grade.

I helped him recreate the coin-flip experiment in Logo and then we did it again for the coins. The cards were beyond his programming skills but he followed along OK when I wrote the code and he got a kick out of the results.

Challenger School – where my little clown learned his nine year old skills – gets a bad rap for allegedly teaching rote learning. But the rap couldn’t be further from the truth. Having sent one little clown to Challenger and another to public school, I can attest that only one of them was ever subject to rote learning and it wasn’t the Challenger clown.

Challenger is intensely academic and, while I can understand that it is not right for every kid, mine was challenged in ways that he didn’t experience again until high school. In fact, I wonder whether the transition from high-performing fifth grader to coasting sixth grader wasn’t detrimental to his determination as it taught him that coasting was an option; an option unavailable to him at Challenger.

Fast-forward nine years and my little clown is now all grown up and accepted to UC Santa Barbara and, under protest, Ragged Clown Sr and Ragged Clown Jr are on their first road trip together to go check out Jr’s home for the next four years. It’s a long trip so we brought along Jad Abumrad and Robert Krulwich for company.

Jad and Robert – and their magnificent Radiolab podcast – have long been our companions on road trips. On this particular trip, the podcast app summoned up the episode “Are You Sure?”

Radiolab episodes have a certain structure. There is always a main theme – in this episode the theme was doubt –  and they do a powerful job of exploring variations on the theme with an  eclectic selection of interviews and zany editing and contributions from psychologists, scientists and moral philosophers – and anyone else who has a good story to tell.

The first segment was interesting albeit not relevant to my story here. A couple of devout Christians were due to get married until one of them started to wonder whether all that stuff in the bible was actually true. That topic would make a great blog post, but it was the second segment that intrigued me more.

Anny Duke is a decision strategist – a poker player – and won the poker world championship in 2004. In her segment, Annie describes the strategy that professional poker players use for winning poker games: know the odds. But knowing the odds doesn’t just mean knowing which hand is likely to win; it means understanding that the hand that is most likely to win will often lose (and vice versa). The secret is in knowing the pot odds.

Annie:

If there is a \$300 in the pot and you have to bet \$100 to stay in, you could lose the pot three times and still break even if you win the next hand.

Robert:

So you could lose a hundred dollars on Monday, a hundred dollars on Tuesday, you could lose another hundred dollars on Wednesday, but if you win the hundred back on Thursday, you are good.

So you just need to win one out of every four times

In other words, it’s not enough to know your chances of winning. The important thing is that your chances of winning are greater than the pot odds.

The climax of the story has Annie playing against her brother in the final of the World Hold’em Championship. They are playing for two million dollars and she’s holding a pair of sixes and her brother goes all in with a pair of sevens before the flop. Her brother is 82% to win the hand. Amazingly, the flop gives Annie a full house and she wins the \$2,000,000.

Aside from the lessons on how to play hold’em, Annie’s good luck highlighted some fundamentally different ways of thinking in the Clown household. There’s one strand of thought that says, if there is a chance that a bad thing might happen at a particular event, you should avoid events like that in the future. Bad movie? No more movies! Awkward silence or said the wrong thing at a social gathering? No more social gatherings! On the other hand, the more optimistic clowns are willing to tolerate a lot of  crap movies and awkward gatherings in the knowledge that, eventually, you’ll find a movie to enjoy or that a social gathering will sparkle. Even without knowing the pot odds, I’m pretty certain that if you never take a chance, you’ll never win.

Final word from Annie:

It’s not about winning the hand all the time. It’s about winning the hand enough of the time […] That embracing of uncertainty does some really wonderful things for you.

You learn how to avoid that very human tendency to feel ashamed or embarrassed when you lose. You just float right above it.

Annie’s brother:

If you are making good decisions, then you are making good decisions.

Annie:

You have to be somewhat outcome blind.

By coincidence, Annie was a psych major and Little Clown is majoring in bio-psych at UCSB. He’s gonna be a scientist!

I hope he’ll learn from Annie and take some chances. I hope he’ll win some too.

### Ragged Clown

Based in San Jose, California

## 6 thoughts on “There’s a one in five chance…”

1. Georgina Lawrence says:

Need a private lesson on probability I think 🙂

2. Exercise for the student:

Let’s say your husband invites you for a beer at the Sports Page and there is a one in five chance you’ll have a great time… nice atmosphere, good pub food, high quality family-time. There is also a chance that the drive up will suck, the kids will be whining and all the food at the pub will be deep-fried. It just sound like too much trouble and you might have a horrible time.

Should you stay or should you go?

1. Georgina Lawrence says:

I’ll ask the armadillo lol …. I’m bent double right now … lol

3. Sounds like a really fun science project. I miss those.
Campus looks beautiful. I miss university too.

Odds are looking good for little Clown.

4. Matt says:

Ben and I heard that episode just yesterday! I was surprised that there was such a fundamental point to gambling that I had not known. Liberating view of failure!

Particularly interesting perspective from the same human on Challenger vs. public school.

I’d be afraid to mess with their science fair format at all, since in my one data point, the kid who experienced it ended up going to UCSB to study science.

There’s a good xkcd on correlation vs. causation…

Post moar!

5. EPILOGUE: Now that another four years have gone by, Little Clown and I are off on a new adventure soon! I hope he enjoys my little stories! There will be plenty of them where we are going.