I'm not a great fan of football but during
The World Cup the tentacled fortune teller
Paul The Octopus has kept me amused.

Germany's oracle "they ink it's all over - it is now"
star has become a worldwide celebrity for his
apparent ability to accurately predict the
outcome of football matches.

He has correctly forecast the result of six of
Germany's World Cup games, and has now
plumped for Spain to take the title.

So just how extraordinary is this cephalopod?
Paul is a common octopus, which is considered
the most intelligent of all invertebrates.

In experiments it has seemingly distinguished
the brightness, size and shape
of different objects.

But mathematicians point out that his run
of predictions is not that extraordinary.

As Paul was predicting two possible outcomes
(win or lose, and not a draw), he had a 1/64
chance of predicting six correct outcomes -
a 1/2 chance of predicting the first game correctly,
then a 1/4 chance of predicting the first two games,
a 1/8 chance of predicting all the first three games,
and so on. The chances of him correctly
predicting seven games, up to
the final, is 1/128.

Chris Budd, professor of applied mathematics at
the University of Bath, says that even highly
experienced people find it difficult to predict
the outcome of a football game, and
compares Paul's feat of "prophecy"
to the tossing of a coin.

"If you toss a coin and it comes down heads six
times, that is unlikely," he says. "However it is
not as unlikely as predicting which numbers
will win the (UK) lottery, which is 1/14 million.
Mathematics can be spooky in the way it can
appear to predict things," he says.

David Spiegelharter, the Winton Professor of the
Public Understanding of Risk at Cambridge
University is not convinced either that Paul's
predictions are that remarkable. The
octopus's run of correct predictions
is all down to luck, he says.

Using the coin analogy, he that says if someone
flips a coin and gets the same result nine or 10
times, it is not remarkable in itself, but it will
seem remarkable to the person flipping the coin.
"Our perception about how chance happens
is not very good, it is not part of our
human characteristics," Prof
Spiegelharter says.

As the world digested Paul's prediction
Spain were indeed the bookmakers'
favourites - exactly as they have been
throughout the tournament.

EDIT 12.7.2010: Paul was right!
Spain took the trophy

No comments: