Mushers are announcing their bib numbers on social media after the banquet last night.  The banquet, and the bib draw especially, is a huge event that creates a lot of excitement. As I was excitedly watching the bib draw, writing numbers in my race guide, I noticed that there was a feeling in the air depending on the musher’s reaction. Every year the bib draw gets me thinking about probability and how a certain bib number may or may not fit a musher’s strategy.  I wanted to know more, so I turned to race expert Terrie Hanke to help me understand how the bib draw really works. It turns out, the bib draw is more complicated than I thought! However, in order to teach probability in your classroom, there’s nothing better than the bib draw!

Tara Wheatland of GCI Holds Mukluk for Bib Draw in 2020 (Photo by: Terrie Hanke)

Here’s the basic idea of how probability works: you are using math to calculate the percent chance of a certain event to happen.  The basic formula is Probability(Event) = Favorable Outcomes/Total Outcomes, so P(A) = n(A)/n(S).  Let’s say you were rolling a die, and you wanted number six–your Favorable Outcome. There is a 1 in 6 chance, or approximately 16%. If you needed either a 1 or a six, the number of Favorable Outcomes goes to 2, so then your probability goes to 2/6, or about 33%. I hope you could find this concept easy to teach in your classroom—obviously Kindergarteners wouldn’t use the formula—but you could show them what probability means by having them draw colored cubes or balls out of a bag.

Now let’s look at why the mushers draw bib numbers in the first place, and why it matters to them.  Imagine you are running a 10K fun run, and you are gathered at the start line with 1,000 of your besties. The gun goes off and everyone leaves at the same time. Of course, you can jockey for position up front, but really, your bib number doesn’t matter because everyone begins the race at the same time. Now imagine thirty-eight sled dog teams jockeying for position at the start of a race—that would be very unsafe for all involved, especially the dogs. So the Iditarod spreads out the start times over 2-minute intervals. That time differential is made up during the first 24-hour mandatory layover, well into the race.

Well, why does starting position matter? Each musher has a different level of competitiveness. Some mushers don’t mind going first or last. Some just really don’t want to go first. Starting at 2pm gives you more running in the sun and heat of the day, while a start 76 minutes later (as per the number of mushers in this year’s race) means you might get colder temperatures after the sun sets on your first run. Each musher has a different run/rest strategy that works best for their dogs. Some mushers don’t want to travel over an unbroken trail, and some don’t want to travel over a trail that might be chunky from 37 previous dog teams. The bib number a musher gets can affect their overall race strategy.

What intrigues me about probability is that for each musher, the Favorable Outcome could be different. For example, if you are drawing names out of a hat for a prize, everyone wants their name, so everyone’s probability is 1 divided by the total number of names. But maybe mushers have a range of numbers that they would like. For example, one musher might prefer bib numbers—and therefore starting order—between 5 and 15. For every person ahead of them who does not draw those numbers, the chance of this musher getting a number between 5 and 15 goes up.  For every person that draws one of those numbers, the chances of this musher getting one goes down. I know there are some really great math equations that could describe this–please share if you are a math person!

Mushers, Volunteers and Fans Attend Picnic at Headquarters (Photo: Sara Lamont)

But wait, there’s more.  At the Iditarod sign-up in June 2023, 24 mushers submitted entries. Those mushers get the first bib-draw at the banquet.  At the close of the June event, all names are drawn randomly. Whoever gets drawn first would be first to draw out of the boot at the banquet, second name drawn chooses a bib number next, and so on.  Any entries received by mail prior to the Iditarod sign-up picnic in June count for that day also.  So last night, even though there were 38 mushers total, only 24 numbers were in the boot when they started the draw. After these numbers were drawn, officials added the rest of the bib numbers for the other mushers who signed up after the event in June. 

The mathematical concept of probability has two layers when looking at individual Iditarod race strategies. What’s more, those strategies start as early as June, a mere three months after the previous Iditarod concludes. I don’t know of any other sporting event that has such a multi-layered starting position procedure—if you know of one, please let me know.

For teachers, this means we can have a lot of fun with our classes teaching not only probability, but also the idea that not everyone has the same Favorable Outcome.  You could start with a bag of colored cubes, marbles, or other similarly shaped object that comes in different colors.  Each student could calculate the probability of getting their desired color based on the number of that color compared to the whole group.  As each student draws an object, students would then re-calculate the odds of getting their desired color—do they go up, or do they go down after each turn?  

You could have a bib draw in your class just for the purpose of teaching probability. But if you wanted, you could also layer in the two-step bib process where some students who finish a task first could be in the first round of drawing bibs—similar to how the mushers who sign up at the June picnic get in the first list of names to draw bibs at the banquet the following winter.  High school classes can calculate the odds of getting their chosen numbers, and I’m sure there are equations that describe how the probability changes with each draw.

Flags and banners displayed at the 2024 Iditarod Musher Pre-Race Banquet and Bib Draw. Photo: K. Newmyer

I’m very thankful to Terrie Hanke for explaining this process so well. (Check out Terrie’s “Eye on the Trail” posts while the race is unfolding.) The annual bib draw at the musher banquet is an important part of race strategy and is just one of the many things that makes the Iditarod so unique.  How could you use the bib draw to teach probability to your students? Email me at email the teacher@iditarod.com.