I was disappointed in the amount of press given to silly predictions during the World Cup. Or rather, I was disappointed that the silly predictions did not lead to a greater discussion of probability and conditional probability.
First, we have Paul the Octopus. Wikopedia claims that he was correct in all eight of his World Cup predictions, and that he is 12/14 overall. Getting all eight predictions roughly has a probability of (1/3)^3 * (1/2)^5 = 1/864 (the first three predictions could have resulted in a tie). Not bad. But Paul the Octopus gained international fame after his first four correct predictions, which means the conditional probability that his last four predictions are correct given that his first four predictions were correct is (1/2)^4 = 1/16. It was unexpected that he would continue to make correct predictions after attaining such fame, but given that there were certainly more than 864 bizarre ways to make World Cup predictions, someone had to get them all right. Still, the octopus is a great mascot.
Next, we have Mick Jagger, who was declared a jinx after all three of the teams he supported lost. Of course, this was done after the fact. Given the large number of celebrities who attended World Cup games, it is not surprising that a few saw their teams(s) win more than others. So that’s my way of saying that I’m not seeing why Mick Jagger was newsworthy.
Are there any other examples of probability–good or bad–that hit the mainstream during the World Cup? Was there any useful discussion of probability during the World Cup? How did you make World Cup predictions (aside from relying on octopuses)?
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