Plus Advent Calendar Door #12: How psychic was Paul?

Paul the octopus

Paul picking Spain over the Netherlands on the 9th of July 2010.

England's dismal performance in the 2010 football world cup was thankfully overshadowed by the attention given to Paul the octopus, who made an unbroken series of correct predictions of match winners. The conclusion was obvious: Paul had to be psychic.

But was this really the case? At the time David Spiegelhalter, then Winton Professor for the Public Understanding of Risk, used some Bayesian mathematics to find out. You can read about his reasoning, and his conclusion, in his article.

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