That was a massive drop (the biggest ever?). It cannot be explained away by assuming Jimmy merely came bottom in the viewer poll.
Am I correct in saying that for everyone below him on the leaderboard, their position in the viewers poll would have to be virtually a mirror image of their leaderboard position?
That is to say, the minimum points needed for survival would be 8 (Jimmy's 7 leaderboard points plus 1 viewer poll point).

Any mathematicians out there who could give a reasonable explanation?

I think we've covered it here:

http://www.digitalspy.co.uk/forums/s....php?t=1384061

There are threads in which the explanation has been given but to save you trawling through them, I'll try to elucidate.

The points from the judges were allocated thus:

1. Kara=10
2. Matt=9
3. Pamela=8
4. Jimi=7
5. Michelle=6
6= Patsy, Felicity, Gavin=5
9. Scott=4
10. Ann=3

So, if Jimi finished last with the public and Michelle second to last, the only things we can be sure of after that are that Scott finished no lower than 7th and Ann no lower than 6th. Anyone else could have finished anywhere from 8th upwards (and in Kara and Matt's case lower than that but I'm presupposing that Jimi and Michelle occupied the bottom two places with the public.)

There is a problem in the way that points are allocated to the judges' scores in the event of tied positions. (Brendan complained about this a year or two ago when they were down to the last 4).

Kara was awarded 10 points for coming top of the ten dancers based on the judges' scores (ie before the viewers voted). . i think jimi was 4th on saturday night so would have been allocated 7 points.

Scott and Ann came 9th and last (10th) and should have been awarded 2pts and 1pt respectively. However because three dancers were tied on 29pts, for reasons that defeat me the bottom end of the scoring went like this :

joint 6th - felicity, gavin etc - 5pts each.
scott - 4pts (came 9th, should be 2pts)
ann - 3pts (came last, should be 1pt).

I'm not a mathematician, but no competitive sport, eg olympics or tour de france, allocates scores like this in the event of a tie.

As a result the gap betwen the top half of the leaderboard, and the bottom two positions was narrowed, and in Jimi's case, he had a smaller lead over Ann and Scott going into the viewer votes than might be expected from the judges' scores.

this may not have impacted the result this week,( the bbc doesn't publish the results so we don't know), but it does mean that it was easier for the bottom two dancers to overtake those in the middle positions.

going to lie down now... maybe a real mathematician could advise.

Regandron's got it spot on with his synopsis

What this highlights is that in the event of people being tied on the leaderboard, it isn't just the mid table who are in trouble but the upper half as well. Viewers who vote are generally not aware of this and continue with their practice of saving those who they believe are in danger blissfully ignorant of the reality. Then it comes as a surprise when someone 4th on the leaderboard goes.

I have to say the BBC doesn't help this by showing the table in 2 halves as it subliminally tells people to vote for the lower half. If the programme really did want us to vote for our favourites as Tess says every week then they shouldn't show the table at all. That way people who aren't "statistically aware" wouldn't be misled.

I wonder if the judges were aware when scoring that they would be tying couples?

Len's 9 was definitely a reaction to Craig's 4, I'm sure that he wouldn't have normally awarded that. For the last dance, they must have worked out there would be a draw. Does anyone know how much discussion there is between them before they press their buttons (as paddles are apparently only for audience effect)?

There is no surprise in this change in the voting system.

The BBC were keen for another JS 'Story' this year so that they could generate publicity and controversy and help compete with the XF. They saw what happened with the coverage of JS and subsequently Jedward on the XF and figured this was the way to go.

They obviously chose Widdecombe with this in mind and, knowing she would likely be bottom of the judges votes every week, changed the voting system to ensure that it would be far easier for someone at the bottom of the judges table to survive, i.e. her.

Simples!

Like Cowell, on XF with Wagner, they are treating the GBP as malleable simpletons. Can't blame them, there are enough out there to make it worth their while.

The biggest laugh is that a fair proportion of the people voting for these people think they are the 'rebels' poking the producers in the eye.




Maggie

To be fair, the judging system was changed as a result of the semi-final fiasco with Tom Chambers two years ago. This is one thing you can't blame Ann for, satisfying as it might be.

As I see it this is what happens.

Judges' scores

1. Kara=10
2. Matt=9
3. Pamela=8
4. Jimi=7
5. Michelle=6
6= Patsy, Felicity, Gavin=5
9. Scott=4
10. Ann=3

The two I have highlighted should have got 2 and 1 respectively, but as the previous post said, because of the "Tom Chambers effect", the voting was manipulated to make it the way it is now.

I wonder if the viewers' votes are manipulated in the same way.

If three are tied on 5 points each then the 4 and 3 point scores should be unavailable and that would leave Scott with 2 and Ann with 1.

They only brought in the new system to make sure that it was always possible to save the public's favourite from the dance off. Now there is no dance off they should revert back to the old system you have described here. Of course John Sargeant went a long way under the old points system too!!

Even without the changes to the scoring, mid table has always been a risky position to be in before the public vote.

^^
the event of a tie in the viewers vote is extremely unlikely - so the scores will spread out after they have been added.

What they could do is what DWTS do which is convert the points to percentages... they add up the total points from the judges and convert each contestan's score to a percentage of the total...
eg 10 contestants all get 30 points - total judges points = 300 each contestant gets 10%

they do the same with the public vote
total phone votes 1,000,000
contestant 1 500,000 = 50% + 10% = 60/200 = 30%
contestant 2 300,000 = 30% + 10% = 40/200 = 20%
contestant 3 200,000 = 20% + 10% = 30/200 = 15%
the rest - zero votes so 5% each......
(hopefully you get the idea from that)

etc etc so again they get the scores stretched out and the one with the lowest overall percentage goes.

That said - DWTS isn't immune from shock exits and duffers outstaying their welcome either. The other week the couple who were second with the judges went home (and they were pretty good!) so clearly had NO public support - just like Jimi.... and Bristol Palin who is one of the worst dancers (but it must be said not in the same league as Ann or Gavin) has managed to get to the final 5.... people reckon she is getting the support of the Republican/ tea party supporters to keep her in (her mum is Sarah Palin who was the running mate mate of the Republican presidential candidate in the last US election...)

Sadly ... or happily ... competitive sport/Le Tour de France doesn't rely on public voting for half the marks - else I may have bankrupted myself these last 2 years on behalf of Mark Cavendish

Another way to seperate the block of tied votes is just to have the judges rank the tied couples.

So, Felicity/Patsy/Gavin all on 29 ... the judges just have to decided who was slightly better and should get the 5 points, 2nd for 4 points and third for 3 points, which means that the 2 and 1 for the bottom couples follow on as normal.

I do find it hard to believe that Len and Bruno both marked 9 couples with only 2 of the scores available (8 or 9).

Their leaderboard would have read:
Very good - 10 points.
Quite good - 9 points.
A bit pants - 8 points.

How can they get angsty if the public 'don't agree' when they've really given them nothing to agree with.

I have been complaning about this in my last few posts as well. It's ridiculous.
I know they changed it to this way because of the time there was only 3 competitors left and the first two tied but surely they could have thought of a better way of doing it. If that ever happened again which made the viewers vote for the third placed person worthless then why didn't the judges just score the first two again and award a first and second place.

When judges say 'It's your best dance to date', it's like a death sentence to those in the middle of the leaderboard. It redirects the votes to those who 'need them more'.

I don't think the old system was fair in the event of a tie. We would have seen the three dancers who scored 29 each get five points, and then Scott get two points for scoring 28. A three point drop doesn't seem right when there was only one mark difference.

In my experience the way sports would tend to award points in a situation like this would be to give each of the people in a tie the average of the points that would be awarded for those positions. On Saturday that would have meant that as the tie covered positions 6, 7 and 8 which are worth, 5, 4 and 3 points, the three couples would each have been given the average of 5, 4 and 3 which is 4. This would have left them 2 points behind Michelle and two points above Scott.

The fairest would be to award points as a proportion of the points they scored in the dance. It hardly seems fair that someone who scores more than ten judge points for a dance only is awarded one placing point more. I haven't completely worked this out yet though.

EDIT: and it's assuming the judge scorings are fair in the first place.

Flavia and Jimi were on ITT last night and Flavia didn't understand how they went from fourth to being eliminated. I don't either so I would like a Strictly producer to appear on ITT and explain.
What are my chances of that happening?
I think very slim or positively skeletal lol

Some good brains doing good workings here, thanks
Bit clearer, but still makes no sense to me.

Its easily explained.......in order to drop from 4th to last then all the people below Jimi on the board (Ann Scott Gavin Patsy Felicity and Michelle) all got more votes than him.....also Pamela above him got more votes or she would have been out rather than him. Kara and Matt COULD have got less votes than him and still be safe because of the points they got from the judges but otherwise its a simple as that .......all the people I have named got more votes than him and he dropped from 4th to last.......its not magic or a conspiracy its just lack of public of support....or perhaps put another way.......more support for people other than Jimi.

The actual points people got from the public can only be guessed at but for example Ann would need to get at least 5 points from the public to overtake Jimi.

Somebody would have to tell Len there are also paddles 1-4. Now the relative position is enough. And you could do the same with public vote and distribute the points proportionally, too. Let's say you would be distributing (10* number of dancers) points both from judges and public.

So you would have

Leaderboard_points_judges_dancer(10 dancers) = 10 * 10 * sum_points_from_judges_dancer / total_of_points_from_judges

Leaderboard_points_public(10 dancers) = 10 * 10 * sum_votes_from_public_dancer / total_of_votes_from_public

Add these together and you get leaderboard points for each dancer. In an event of tie, public has a higher priority.

Len's 9 was definitely a reaction to Craig's 4, I'm sure that he wouldn't have normally awarded that. For the last dance, they must have worked out there would be a draw. Does anyone know how much discussion there is between them before they press their buttons (as paddles are apparently only for audience effect)?

I sat behind the judges on one of the live shows this year and they certainly don't appear to discuss scores prior to holding up their paddles. However, who knows what goes on prior to the live show??

Well, it can be that people want to save everybody, sending more points to those lower on the judges leaderboard. Those on top will usually survive even without a public support, but those in the middle suffer because they have not enough public support. It's not that people do not like them, they just think somebody else need their support more. So paradoxically better ones leave first. And a certain clown just has a steady support not influenced by movements on the leaderboard.

I remember somebody (Len?) saying that when the dance ends they have pressed the buttons already Maybe they changed that or they say each other even before that how they are going to vote.

Indeed not, but no Olympic sport has a phone vote. The current system re ties on the judges' scores was brought in for 2009, to stop the scenario from the semi in SCD 2008 where Tom was doomed to the Dance-Off irrespective of the phone vote after the other pair in the semi tied for top spot.

There's nothing wrong with this from a competitive viewpoint, but the Beeb was in potentially hot water given numerous phone-vote scandals after Tess urged the public to vote to save their favourite, which for most voters (Tom supporters) was impossible.

In the early stages, there are a lot of potential combinations of judges' scores and phone votes, so there's always the potential for Tess to urge the impossible once again, and the new scoring system dramatically reduces this chance. As a mathemetician, I'd prefer Tess to urge people to undertake their own analysis of potential outcomes and vote based on their preferences, subject to what is mathematically impossible, but I guess I'm swimming against the tide here!!