The ball bet

What are the odds of more than twelve named Atlantic hurricanes in 2021? That Bitcoin will top 75K in 2021? More than 2M travelers through TSA in a single day?

These, and more, were part of the 2021 predictions. That post built on the ideas of Superforecasting, which offers ideas towards better predictions. Julia Galef adds another.

Here’s one of the prompts: Will I lose power at my home in Central Florida for more than three days? I figure these odds were about 10%, and would wager that, no, we will not lose power for more than three days.

Imagine another prompt. In this bag of twenty balls there is one red and nineteen black, pick the red one and win. Okay, simple enough. There’s a five percent chance to win the red. And here’s Galef’s guise, you can only play one game.

Do I feel more confident about the hurricanes making landfall or the finding of the red ball? The hypothetical ball bag bet can slide up or down: 5%, 10%, 30%, etc.

“You just ask yourself, do I feel more optimistic about taking that bet or [the other]…You can play with the ratio of balls to kind of narrow down the number you put on your confidence in the original question.” – Julia Galef, BBC’s More or Less, August 2021

With my kids we use coin flipping. One day I had an appointment and told them there was a 5% chance they would have to go to after care at the school. “That’s like flipping a coin and landing on heads four times in a row” I told them.

Probabilistic thinking is difficult but it can be helping in making good decisions. Poker’s appeal highlights this idea too.


The TSA’s nadir was 87,000 travelers the week of April 13 2020, down 95% from the same week in 2019. In 2021 that number was more than one million. The week of June 11, 2021 there were more than two million travelers. I guessed there was a seventy-five percent chance that would happen.