At each of our workshops, we run prediction market games throughout the weekend, which are a chance for participants to check their credence and practice updating their beliefs based on new evidence. When one of the participants suggested a Game of Thrones-themed market at our June workshop in Berkeley, I was happy to acquiesce.


Betting on how likely our group was to be able to name five houses from Game of Thrones seemed like it would underscore the lessons of two of our classes. There was, naturally, our session on Bayes, which could help guide the bettors' beliefs, as they checked in with each other about whether they watched the show or read the books. But, at this workshop, we were also debuting a class on mnemonics, so I thought that this bet might give people a fun use-case for the skills they'd just acquired.

And, indeed, one of the participants put up a list of Game of Thrones houses, and started trying to build a coalition to design and teach mnemonics to the rest of the group.


But the people who had shorted the market also had access to markers and paper, and, soon, just as in Westeros, there was a proliferation of pretenders.


We had gone far beyond mnemonics and simple probability calculations. Participants began to really innovate.


Stymied, the opposing bettors added (non-blue) graffiti to the list ("Chaos is a Ladder!") and debated going to a store to buy a new blue marker. By the time the market closed and was adjudicated, somehow another marker had surfaced and new blue signs had emerged.

It did the schemers little good, however, as the participant chosen by my random number generator was a Game of Thrones fan, and was able to rattle off houses easily (albeit a little regretfully, she herself had shorted the market).

But, by the time the workshop ended and participants listed the lessons they'd learned, it was clear they'd drawn the right conclusion: