tw's blog

Die Roller intro

The Die Roller1 is a folly project I’ve been working on over the past couple of years to determine whether a given game-playing die or set of dice are fair. It consists of a machine that rolls a die over and over, a camera that takes a photograph of the die after each roll, a computer program that recognizes which die face is in each picture, and some statistical analysis software.

I’m interested in answering some simple questions, like “Are my (or your) favorite Dungeons and Dragons dice reasonably fair?”, as well as some deeper questions like “Which common design features help or hurt dice fairness?” and “What do we mean by ‘fair,’ anyway?”

I’ve enjoyed this project because it combines a lot of great stuff: Electronics, mechanical engineering, computer vision, statistics, user interface design, game theory, and 3D printing. Oh, and fig bars.

I hope to post about more detailed aspects of the project over time, including what I learn about die design. If some aspect of the project interests you, please comment - I’d like to see what purpose this could serve in the wider world.


  1. Needs a flashier name - any suggestions? Preferably with a domain name that’s not currently taken??  read more...

Another obsolete problem solved!

I have successfully added non-volatile memory - something like a thumb drive - to a 30-year-old computer that had no permanent storage. Basically, the only person who cares is my 9-year-old self. But he’s dancing with glee!
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Halloween skull project

I’m thinking I should transition this site to be mostly a list of pointers to where I’m actually posting the things I create, which is on a bunch of other sites.

So, here’s one: I’m exploring Factr, and I’m documenting this year’s Halloween project there, a skull that watches you.

Troubleshooting Rule #7: Poke it with a stick

At this point in the troubleshooting process, you’re starting to feel desperate, willing to try anything, even poking the problem with a stick. Do that. But don’t do it desperately, do it scientifically. read more...

Don't waste a good failure

My troubleshooting rules can really help focus on solving a problem, but maybe first you’d like to not solve the problem for a while.

What?

Well, let’s look at a common sequence of events in creative or constructional work of many kinds:

  1. See a problem.
  2. Figure out how to fix it.
  3. Fix it.

That’s pretty instinctual. Can’t really do those out of order. And once you’ve seen the problem, there is often some amount of urgency to get to the fix.

But the next step, if you’re conscientious, is:

4.. read more...

Weber's Troubleshooting Rules

These rules certainly apply to software of all kinds, and electrical engineering, but they are also basic enough to apply to interpersonal issues, group dynamics, etc.

  1. Is it plugged in?
  2. Is it turned on?
  3. Is it working as designed?
  4. What’s changed since it worked?
  5. What don’t you know?
  6. Who haven’t you talked to?
  7. Poke it with a stick.
  8. Simplify!

And a bonus rule:

0. Don’t solve it too soon!

Troubleshooting Rule #4: What's changed since it worked?

Sometimes when troubleshooting, you look at the problem very closely as it exists now. But in many cases, you can look back at what things were like before the problem existed. What worked then, and what has changed since that time? read more...

Troubleshooting Rule #8: Simplify!

If you’ve gotten this far in my troubleshooting rules, this is a tough problem. Maybe you can solve it…

… but maybe instead you can replace the situation with a simpler one that will be less prone to problems? read more...

Troubleshooting Rule #6: Who haven't you talked to?

Maybe you’ve been troubleshooting for a while on your own. Or maybe you’ve discussed the trouble with someone else, but not the right someone else. Who could you talk to? read more...

What are fair dice?

If you like games, you’ve probably played games with dice, and you’ve probably thought about fair and unfair dice.

You might have seen “trick dice” advertised in the back of a comic book, for instance, or you might have flipped a string of heads on a coin and thought your way into the Gambler’s Fallacy or an instinctive Bayesian sense that the coin is biased towards heads.

If you have studied statistics, you’ve encountered more mathematical ways to treat these human observational instinct read more...