Paul - the soothsaying cephalopod

Article in today's Times included below. I should have included the important observation that even if Paul's final two predictions are correct, it does not change my total belief that he is not psychic and the results are just chance. Essentially when a hypothesis has zero initial probability, no amount of surprising evidence will shift that belief. Oh dear, what a closed-minded person I am.

It’s definitely time to retire. I and all my profession are being humiliated by the apparent ability of Paul the psychic octopus to predict the results of Germany’s World Cup matches. I’ve collected an alphabet of letters after my name from 35 years of analysing statistics and making predictions, and yet some soothsaying cephalopod, doubtless with few GCSEs, has got 6 out of 6 correct including the two defeats.

No interviews with Paul are currently available and so we don’t know his thought processes when his Delphic tentacle reaches out and picks the winning team, but he is probably not analysing the data on past performance which forms the basis for most football prediction systems. I recently tried my hand at this and suffered the derision of John Humphreys for my subsequent failure, and analysts at major banks also took time off from their money-making to make World Cup predictions. JP Morgan predicted England to win the Cup (although put Netherlands and Spain as 2nd and 3rd), while UBS, Goldman Sachs and Danske Bank all put Brazil as the most likely winner. Sadly this performance is unlikely to affect their bonuses.

That octopus is destroying my life’s work. I work in a team concerned with improving ‘risk literacy’, who go into schools and explain how lotteries are unpredictable whatever your Aunty says, and that just because red has come up on roulette 4 times in a row, it does not mean that somehow it is black’s turn. And that rather remarkable ‘coincidences’ happen by chance alone, such as in a class of 35 children there is an 81% chance of two having the same birthday, or that if you flip a coin 20 times there is a 75% chance that you will get a run of at least 4 heads or tails in a row. Also, when Derren Brown flipped 10 heads in a row, it was only after he had been flipping for 9 hours and they only showed the bit of film when he finally succeeded.

Most remarkable predictions turn out to due to this kind of selective reporting, and at first I assumed we were only hearing about Paul’s success and not about the hundreds of other sea-creatures picking North Korea as the World Cup winners. But now Paul’s predictions are being publicised beforehand, without any Nostradamic ambiguity. The pressure is on – can he perform under the full media spotlight or will he do a Rooney and disappoint? For some bizarre reason I can’t help hoping that he does get the next predictions right, even though it will mean my erudite lessons in chance will in future be greeted by derisive sneers of ‘OK prof, how do you explain the octopus?’