### Derren Brown lottery prediction deep maths error

I just finished watching the marvelous Derren Brown’s “How to Win the Lottery” program, as well as watching the live “prediction” last Wednesday where he reveals the numbers after the draw.

In the show, he points our attention to The Wisdom of the Crowds, where a group of people guess the weight of something. It’s a pretty good theory and one with a pretty understandable explanation. You ask 100 people how much does a bull weight, and work out the average. The key point here though is that the people can see the bull. They have a target to aim at when making a guess. If you ask 100 people to throw a dart at a target they’ll get near it on average.

Derren claims to use the same technique for the lottery.

I have a normal 6 sided dice (numbered 1 to 6) and I ask 100 people to guess what number will come up next. Their average is 3.5. (1 + 2 + 3 + 4 + 5 + 6 = 21 / 6 = 3.5)

The bull’s weight is a single number, something we can estimate.
A dice is random, so a roll of 2 is the same as a roll of 6.

With the National Lottery, we pick numbers 1 to 49, giving an average of 25. With the group he used in his show, note that the numbers they got all tended towards 25.

Replace the Lottery numbers with symbols and letters. Smiley face, triangle, "G", square, the colour green, "23", a banana. Their numeric "value" has no meaning. How much does that bull weight?

I don’t have a better explanation for how he came up with the numbers. I just think the method he explained is wrong.

Update The Telegraph share the same disbelief. "Roger Heath-Brown, professor of pure mathematics at Oxford University, said: "Mathematically it is complete rubbish. It is a bluff on his part, he is doing it in some other way." "