Following a workshop on the idea of counter-intuitive mathematics, I was intrigued to find out more about how we can look past our intuition or gut feelings to understand mathematical concepts such as probability.

I am someone who struggles to grasp this mathematical concept, as I cannot see past the black and white picture: that everything that happens is completely random and cannot be controlled. To gain a more open mind about this topic I watched the documentary by Derren Brown – The System. This documentary focuses on trying to defy our understanding of probability and to see “the bigger picture”. Derren demonstrates this through inviting people to participate in horse race betting – telling them that he can guarantee they get a win every time.

We follow the journey of Kadesha, who has won every bet since being given anonymous tips from Derren Brown. When Kadesha eventually meets Derren, he explains to her that he has come up with the first “system” which will guarantee her a win for every single horse race she places a bet on. A mathematician worked out the probability of a system being possible to predict the horses accurately and came back with the result 1.48 billion:1 (which is not completely impossible but highly improbable.) So then how can Derren guarantee a win every time?

The truth is, he can’t. What we don’t know as we’re watching Kadesha’s winnings is that there have been 7,775 losses in the process. Altogether, Derren contacted 7,776 random people to take part in this experiment, knowing that someone was bound to win every race. This is because of the extremely high number of people taking part. For each race Derren randomly divided the participants into groups for each horse in the race (so inevitably, one group had to win each round). Kadesha was lucky enough to be part of the winning group every time until the 6^{th} and final race when she was on her own and Derren could only choose one horse who he thought would win (unlike every other round when he could choose all the horses and at least one person would win their bet.)

This is something which didn’t even occur to me as I was trying to work out how this system was possible. I was honestly convinced Derren was a magician! But now, it makes perfect sense. **The system works because Kadesha is not alone. **This is exactly the way probability works. The more chances or opportunities you give yourself the more likely you are to be successful.

Derren used a similar example with flipping a coin. He explained that he would flip a coin 10 times and every time it would land on heads. What we don’t realise watching the show is that he had been flipping a coin all day until it came to the point when it landed on heads 10 times in a row – so inevitably it was going to happen eventually.

As stated by Derren: “to work out the system you need to understand that we can only know what comes from our own limited experience and our experience can be very far from the truth.” In my opinion this a great way of explaining counter-intuitive mathematics. If I was someone who had a greater understanding of probability, maybe I could have figured out the hidden secret behind Derren Brown’s “system”. This documentary has also highlighted the importance of looking at concepts from a very open mind (which is something I’ve always struggled with in mathematics and have mentioned in previous blog posts). These are both very important aspects of learning mathematics that I will take forward with me in the future: to look at mathematical concepts from a very open mind and to see how the concepts link with my own experiences or experiences of others.

I have linked below the documentary if you would like to find out if Kadesha won the final race or lost her £4,000 worth of savings… I have also linked an article which explains/criticizes the show.

http://www.independent.co.uk/news/media/sport-on-tv-hes-never-wrong-but-brown-fails-to-frighten-the-bookies-777421.html

References

*Derren Brown – The System (Full).* (2011). (video) YouTube: ScepticaTV. (https://www.youtube.com/watch?v=9R5OWh7luL4&t=2506s)

Tong, A. (2008). *Sport on TV: He’s never wrong but Brown fails to frighten the bookies.* The Independent. [online] Available at: http://www.independent.co.uk/news/media/sport-on-tv-hes-never-wrong-but-brown-fails-to-frighten-the-bookies-777421.html [Accessed 30 Oct. 2017].