Strictly Stats

The Independent newspaper used to run a feature called “Questions to which the answer is no”.

The Radio Times has an article about Strictly Come Dancing that could fall into that category… maybe.

I am not a Strictly fan (someone sent me the link), but it’s a nice article to use with a class.

I am going to show this to a class and ask them to comment on whether this will be a good way to determine the eventual winner.  So, what did the Radio Times do with their trusty calculator?

They added up ten numbers and then divided the answer by 10 to work out the mean.

They then compare the ‘average score per dance’.  But wait: everyone has done ten dances, so everyone’s total is divided by 10.  So actually they could just have used the total.  That is a nice talking point.

Then there is the differing methodology.  The winner is the one who gets the most points in the final, not the dancer with the most points across the series, so there is no nailed-on reason as to why this must work.  It might be a good pointer to the eventual winner though.  Can we test that out?

Well if this is an accurate method then surely it will have worked last year?  The pupils could download the data themselves and find out.  It’s all available on Wiki (which is where my data below comes from).

Let’s have a look.  Here they are shown in the final order, so Caroline & Pasha were the eventual victors.

After 10 weeks last year the leaders (on average … and in total) were waiting to be eliminated after the next round, whereas the eventual winners were in third position.

I looked at two other years.  In 2013 the eventual winner was leading after 10 rounds.

In 2012 the eventual winner was third after 10 rounds.

This could all be discussed with the class and they could find out similar info for all the other editions of Strictly too.  (Maybe the years could be shared out so two or three members of the class analyse each year as a homework task?)

Of my sample of three years, in 2/3 of them the eventual winners weren’t in front after ten weeks.  I wonder what happens overall.