Saturday's edition of Strictly Come Dancing was thrown into chaos.
The TV show's producers realised that it was mathematically impossible for a public telephone vote to influence the contest.
This came after the marks the studio judges awarded put two of the contestants in joint first place.
The BBC executive in charge of the programme put the problem down to "exceptional circumstances".
More or Less listener Dirk Nachbar disagrees. From his hospital bed, he ran a computer simulation, based on past scores, and concluded that the chance of such a problem was 1 in 8.
Our reporter, former computer programmer Oliver Hawkins, has run his own simulation and come up with a similar result.
Watch him explain it.
Tim Harford's article about the voting fiasco.
More maths of the credit crunch
Which maths error may have contributed to the credit crunch?
Financial mathematics guru Paul Wilmott continues with his
More or Less series explaining how mathematical blunders contributed to the credit crunch.
This week, he talks us through the maths error that might have contributed to the mispricing of financial derivatives and thus to the travails of the banks, the credit crunch, and the recession.
Imperial measures: why do they refuse to die?
Tim Harford talks pounds and kilos with Derek Pollard.
Pints, miles, pounds and inches. They are fiendishly complicated and politicians have tried to ban their use, but for some reason imperial measures have proved impossible to kill off.
This week, the European Parliament voted to allow UK consumers to use both metric and imperial measures. It marks the end of a long campaign to make Britain fully metric.
Warwick Cairns, author of
About the Size of It explains the appeal of imperial whilst Derek Pollard, Secretary of the Metric Association vows to carry on the fight for a "single rational system".
An imperialist and a metricist argue their case
Warwick Cairns' article and your comments on metric Vs imperial.
The Chief Medical Officer for England, Sir Liam Donaldson, this week reiterated his appeal for urgent action on childhood obesity, claiming in an
online article for BBC News that "the obesity epidemic" is a national crisis and that to do nothing was not an option.
According to the Health Survey for England, a quarter of 5 year olds are obese or overweight. Simon Cox, presenter of our sister programme
The Investigation explains why the figures exaggerate the extent of the problem.
Read more about
The Investigation's findings. Knife-crime statistics
"Fewer teenagers are being wounded by knives" claimed a Home Office press release issued last week.
How accurate are the latest government figures on knife crime?
Figures in the document purported to show that the government's Tackling Knives Action Plan had been a great success.
The head of the UK Statistics Authority, Sir Michael Scholar, disagreed.
On Friday he condemned the government for releasing "unchecked" and "selective" numbers against the advice of professional statisticians.
So why might an apparent fall crime be not all it seems? It could be something to do with a concept called "regression to the mean".
Read more about
regression to the mean.
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More or Less is broadcast on Friday, 19 December at 1330 GMT and repeated on Sunday, 21 December at 2000 GMT. Subscribe to the More or Less
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