video thumbnail 27:28
The unexpected logic behind rolling multiple dice and picking the highest.

2022-07-01

[public] 57.7K views, 58.5K likes, dislikes audio only

channel thumbStand-up Maths
3840×2026

Check out Jane Street's icosahedron puzzle:

https://www.janestreet.com/IMO2022/

2022 International Mathematical Olympiad!

https://www.imo2022.org/

If you want those d60 and d120 we sell them on Maths Gear or you can go direct to The Dice Lab.

https://mathsgear.co.uk/collections/dice

https://www.mathartfun.com/thedicelab.com/d120.html

Here is my terrible python code.

https://github.com/standupmaths/higher_of_two_rolls

Thanks to Gilad Levy for sending in the question. This is the best collection of maths about the problem we found at the time: https://rpg.stackexchange.com/questions/14690/how-does-rolling-two-d20-and-taking-the-higher-affect-the-average-outcome

But much of that looks at getting a certain value OR GREATER whereas I focused on specific values and the average value.

I’ve also noticed that Chalkdust just beat me with a similar article. Nice to see a different way (induction) to derive the same probability of getting specific value equation! https://chalkdustmagazine.com/features/slaying-the-dragon/

Cheers to my Patreons for buying me all those dice. If you think I still don't have enough dice, get involved here: https://www.patreon.com/standupmaths

CORRECTIONS

- Yes, on the bar chart axis it goes 2%, 4%, 2%, 4% instead of 2%, 4%, 6%, 8%. First spotted and pointed out by Deadeaded. It was just because I was copying and pasting in photoshop and forgot to edit it. Not because I was making that chart in a bar.

- At 23:07 I have (n=1) in the graphics which should be (n-1). Or maybe I put in two - and you should pick the highest. (Pointed out by Leick Robinson.)

- Marco Davi correctly noticed that the fifth Rhombic Dodecahedral Number is 369, not the 269 you see at 21:46.

- Let me know if you spot any other mistakes!

Filming and editing by Alex Genn-Bash

Dice gluing by Alex Genn-Bash

Putting 1/n in front of everything by 1/nMatt 1/nParker

Music by Howard Carter

Design by Simon Wright and Adam Robinson


Stand-up Maths I do mathematics and stand-up. Sometimes simultaneously. Occasionally while being filmed. (It's quite the Venn diagram.) Principle channel supporter: Jane Street https://www.janestreet.com/ http://standupmaths.com http://twitter.com/standupmaths
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