For those who didn’t see last night’s The Events on C4, it is the latest project from UK’s very own mentalist, Derren Brown. In the first installment he claims to have predicted Wednesday’s lottery draw, and then revealed how he did it two days later. The program turned out to be a wonderful piece of entertainment dressed up to look like something educational — or should that be the other way around?
The bit I found most interesting was the coin flipping experiment that he reframed as a competition between two coin flippers. One challenger flipped a coin until he observed three heads in a row, whilst another flipping on Derren’s behalf was looking for a pattern tail-head-head. They each took turns flipping and the side that saw their target sequence first was declared winner of that round. Intuitively, one would think that each of the 8 patterns of 3 coin flips (HHH, HHT, HTH, etc) would be equally likely to turn up, yet Derren’s side won most of the rounds in this game. Unlike the other segments of his show, this one used almost no trickery at all. The coin tossing problem is explained quite well by Oxford mathematician, Peter Donnelly in his TED Talk.
Derren Brown chose tail-head-head (he could have chosen head-tail-tail) precisely because he knew this sequence was the most likely one to turn up in a continuous stream of tosses. If both flippers were instead allowed to flip three coins during each turn, then the original intuition would apply — all 8 outcomes are equally likely.
However, the winning strategy Derren claimed to be using makes absolutely no sense. What if the challenger chose HTT, they what would you do?
Update: I’ve looked this sequence over, it is now apparent that both teams are looking for the their chosen combination in one shared sequence of tosses, and not as I had assumed previously, two independent sequences of tosses. This set up makes the game non-transitive and is called Penney’s Game.
As for the rest of the explanation of using crowd sourcing to predict a purely random outcome, perhaps it is fitting that this stunt coincides with the week in which the financial media commemorates the one year anniversary of the collapse of Lehman Brothers and the near catastrophic meltdown of the financial market. A lot of people staked their entire future in the collective wisdom, rationality, and self-correcting crowd sourcing nature of the free market and then got it so spectacularly wrong.
So, how did Derren Brown really do it? One possible method is a camera trick:
Or any other method whereby you load the numbers on the rack moments after the lottery draw. It’s the bigger budget version of the trick demonstrated in this video clip:
The really clever bit is in delaying your “prediction” without people noticing.
In summing up what Derren purports to be the explanation, I’m tempted to cite Douglas Hofstadter’s comments on the Singularity movement that has grown up around Ray Kurzweil:
It’s as if you took a lot of very good food and some dog excrement and blended it all up so that you can’t possibly figure out what’s good or bad. It’s an intimate mixture of rubbish and good ideas, and it’s very hard to disentangle the two, because these are smart people; they’re not stupid.
The difference here is that Derren Brown is an entertainer and not a futurist, and he knows very well which is good and which is utter bollocks. Though I’m not so sure that the same can be said of many futurists.
I look forward to next week’s The Events in which Derren Brown claims to take control the nation of TV viewers. If the social media buzz so far is anything to go by, and especially if there is a significant increase in syndicates (most of which consisting of 24 gullible people) taking part in next week’s lottery, he can comfortably claim to have already achieved this feat.