Who will win Strictly? Ask nan.

Each week we rank Strictly contestants based on social media analysis. We call this the Strictly Sentiment score.

Who will win the Strictly final? It's the question on everyone's lips and it is no exception here at SPARK.

We thought we'd look over the data from the semi-final to see if this gives any clues to the likely winner. Bill topped our Strictly Sentiment poll last week as he has done in seven of the eight shows. This fact on its own would make him a strong favourite if the winner was based on Strictly Sentiment. But it isn't. It's based upon a public vote and people who tweet during the show may not necessarily reflect those who vote on Strictly (either online or by telephone). More on this later.

We know that young and old and men and women often vote differently from each other in polls (which is what the Strictly public vote is). So what do we know about the all important age and gender of the fans of each of the contestants? We are able to run a program that scoops up publicly available Twitter data (such as name and user name) and run tweets through some software that tries to predict the age and gender of tweeters. The results are by no means perfect but they are a very useful indicator nonetheless.

We ran the demographics software through tweets from last Saturday's semi-final and found that about one quarter (23%) of tweets were from women aged between 30 and 39. Just over one in six tweeters (15%) are women aged over 40 and the same percentage are women aged 18 and under. Conversely, males under 18 make up only 4% of tweeters but 12% are aged 40 and older.

The big question now is who does each of these demographic groups favour? The largest of our groups (women aged 30-39) supported Bill then Maisie, HRVY and Jamie in that order (we have taken Ranvir out of the rankings).

Age and gender of people who tweeted during Strictly Come Dancing semi-final 2020 and who they supported (ranked)

The picture was very different for the 18s and under group. Females aged 18 and under favoured HRVY followed by Bill and then Maisie. Males up to 18 favoured Maisie, then HRVY then Bill. In all of the other age and gender groups, Bill was favoured the most. For 40 and over females and for 40 and over males, Bill was most supported but only narrowly over Maisie. Jamie finished last in each demographic group.

We have taken out Ranvir from the rankings as she is not in the final. But where might her supporters go? Again, Twitter gives us some clues. If we look at all tweets that supported Ranvir and one or more of the other contestants, we see that just over one third mentioned also supporting Bill and about one quarter mentioned also supporting Maisie and one in five HRVY. Once again, Bill comes out the winner on this count.

Based on this quick analysis we can summarise that the youngest age group favours HRVY and anyone over 20 favours Bill. Jamie needs the shock of all shocks to win.

At this point we should put a couple of huge warning signs over these numbers. First, it is only based on one show and anything can happen in the final. Second, it is unlikely that the age and gender of people who tweet in support of their favourite contestant accurately reflects those who vote in the Strictly public vote.

Traditionally, the Strictly audience skews towards the older viewer. Ofcom research a few years ago found that 60% of strictly viewers were aged 55 or over. This is double their representation in the UK population (28%). Conversely, only 11% of viewers were aged between 16 and 34 compared with 30% in the UK population. We also know from research that about two-thirds of the audience are women. HRVY and Maisie may well have attracted a younger audience and so the age skew may not be so stark this time round.

What this means is that there are a group of people, particularly older women including 'nans', who may not be factored into our analysis because they are not on Twitter. This group could go for Bill in the same way that Twitter users aged over 40 have or they could get behind HRVY as he may well have more nan appeal than Maisie or Bill.

If the Strictly audience does still skew towards an older age profile then Bill may have the demographics on his side. If younger people vote in greater numbers than in previous series and he gets the nan vote then HRVY is bang in it still.

Once again we will be analysing tweets in real time this Saturday to give some insight into how well each dance has gone down with the public - each contestant does three dances in the final. And we will also be making a prediction on who wins based on our unique Strictly Sentiment analysis. We will do this a few minutes after the public vote has closed.

Strictly Sentiment score

The Strictly Sentiment score is derived from a sentiment analysis of tweets. Using natural language programming and machine learning we classify each tweet as positive, neutral or negative. Tweets are filtered so that they only relate to a celebrity's appearance on the show rather than what they do in their 'day job'. Only tweets made between 7pm and 10pm are included. This is to ensure that tweets relate to Strictly.

We then add up all the positive tweets for each contestant and assign a score between 1 and 100.  This score is based on the relative distribution of positive tweets. We do this to make it easier to compare and contrast Strictly Sentiment scores.