What's the hardest dance on Strictly Come Dancing?

It's something we've heard again and again this year: apparently it's fiendishly tricky to pull off a Cha Cha Cha that impresses the judges and gets them reaching for their 10 paddles.

That got us thinking. Is the Cha Cha Cha the hardest dance in Strictly?

To find out, we analysed every single Strictly performance, gathering them into a massive database (seriously, it's huge) with formulas and averages and everything. As Claudia Winkleman would say, "the results... ARE IN".

When the spreadsheet revealed its scores, the hardest dance turned out to be... the Foxtrot.

Oh. Alright then.

To be fair, Joanne and the rest of the dancers are pretty much right. The Foxtrot is only a tiny fraction of a mark harder than the Cha Cha Cha. Across the whole of Strictly's 15 series, encompassing 1,676 dances, the average score for a Foxtrot was 23.01 out of 40. The Cha Cha Cha, by comparison, earned an average of 23.47.

The Foxtrot has, in fact, caused the dancers a lot of trouble this year. Susan Calman and Kevin Clifton struggled in Halloween Week, earning only 18 points. In Week Two it was the dance that sent Chizzy Akudolu and Pasha Kovalev home after they scored 16 points, and Charlotte Hawkins and Brendan Cole got off on the wrong foot in the first live show, earning just 22 points for their Foxtrot and seriously denting the Good Morning Britain presenter's confidence.

Sure, there have been a few well-scoring Foxtrots (Joe McFadden and Katya Jones earned 32 for their spooky spider dance in Halloween Week, and Gemma Atkinson and Aljaz Skorjanec also scoring 32) but it's not an easy dance style to master.

Plenty of celebrities this year have also fallen foul of the Cha Cha Cha. Jonnie Peacock and Oti Mabuse had a disappointing Pirates of the Caribbean-inspired version, and it was this dance style which also landed Mollie King in the dance-off.

Charlotte and Brendan stumbled through a shocking dance in week two, picking up only 12 points – the lowest score of the series so far. And even if it was the Foxtrot that ultimately sent Chizzy home, it's notable that she only got to perform two dances during her time on Strictly: a week one Cha Cha Cha followed by a week two Foxtrot, which is (statistically speaking) the absolute worst combo.

But what about the statistical anomalies?

Did we average out the week where Bruno Tonioli disappeared and scores were only out of 30, or the one where Donny Osmond popped in with his "Donny Ten" and made the marks out of 50, or the shows in 2009 when Darcey Bussell and Alesha Dixon awkwardly overlapped? Of course we did. We also discounted all Showdances, weird mashups and Waltz-offs and the like.

At the other end of the spectrum, there's the tricky Argentine Tango which results in a surprisingly high average score of 35.06.

That might seem odd given that it usually reduces celebs into (glitter)balls of anxiety, but a glance through the data reveals the reason: the Argentine Tango is only introduced much later in the series when all the useless dancers have been sent home, and is frequently danced in the grand final when the judges get happy with the 10 paddles.

Next on the list is the Viennese Waltz, which earns dancers an average of 30.69 points. All the celebs complain like mad when they get this one, pulling out the vomit bags for their motion sickness as they spin around the room. They should be cheering when they're told they have the Viennese Waltz because it's clearly a top scorer.

Check out the average score for each type of dance on Strictly Come Dancing below.

Argentine Tango – 35.06
Viennese Waltz – 30.69
Jive – 28.17
American Smooth – 28.16
Charleston – 27.76
Quickstep – 27.26
Waltz – 26.92
Samba – 26.79
Rumba – 26.33
Tango – 25.75
Salsa – 25.09
Paso Doble – 24.09
Cha-Cha-Cha – 23.47
Foxtrot – 23.01

What information can we glean from the week seven song and dance list?

It's bad news for Alexandra Burke who has a Cha Cha Cha to I Got The Music In Me by Marcia Hines – although with the scores she's been getting, she can probably survive this tricky dance.

Worse news for Mollie King, who ended up in the dance-off last week with a Cha Cha Cha and now has to take on a Foxtrot to Call Me Irresponsible by Connie Francis.

Ruth Langsford could also be in trouble. She's landed the Paso Doble, which is also right down at the bottom of the list with an average score of just 24.09.

But Susan Calman can take comfort: she has a Jive to This Ole House by Shakin' Stevens, which is third on the list and could pull her back from last week's Foxtrot. And with a Viennese Waltz, Aston Merrygold is sure to get good marks when he performs to Who's Loving You by Jackson 5.

Strictly Come Dancing will air at 6.50pm on Saturday 4th November on BBC1