What football can learn from the tennis tiebreak

In 2012 Portugal lost to Spain after a penalty shoot-out in the semi-final of the European Cup. Did Portugal get a fair chance?

In 2012 Portugal lost to Spain after a penalty shoot-out in the semi-final of the European Cup. Did Portugal get a fair chance?


With the World Cup moving to the knockout stage in some days, a few teams are destined to be ‘knocked out’ because they lost a penalty series.

Statistical analysis based on historical shoot-outs has shown that the team taking the first penalty kick, thereby starting the series, historically won in ~60% of the times.

This statistic should not be underestimated – teams starting the penalty series have a ~50% bigger chance of winning!

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British men are gay. Or naughty during their holidays. Or have non-human sexual partners. Or women are cheaters.

This is at least what the Daily Mail seems to want us to believe. Here, they say the following:

The biggest difference between  men and women lies in the number of sexual partners – with men having ten in  their lifetime, compared to an average of seven for women.

To put it into context, they mean that before meeting ‘the one’ men on average have 10 sexual partners and women 7. That sounds about right, doesn’t it? Yes?

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The Odds of Breaking Temperature Records: Not Extreme After All

Today authorities announced that the day before yesterday was the coldest 11 March ever recorded in the Netherlands. This newsflash may not be very remarkable, if only these same authorities, weeronline.nl, hadn’t announced on 5 March that it was the warmest day ever recorded in the Netherlands!

The last few days were bitterly cold in the Netherlands

So, what’s going on here? A maximum and a minimum temperature record within 7 days?! Is the weather turning sick?

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The Crazy Concept of Life Expectancy

Someone’s life expectancy is the expected number of years he or she will remain alive. It is an average that is computed for several groups of people of varying specificity, such as the entire global population, newborns in Ghana, or 15-year-old women in Europe. It is a statistic used in many debates, especially in those concerning a country’s (under)development. The statistic is always presented with much confidence, that is, no-one really doubts the accuracy and reliability, which becomes clear in thousands of articles, but let’s pick one:

In the two decades to 2010, men’s life expectancy increased by 4.7 years and women’s by 5.1 years – but the extra years of good health were only 3.9 years and 4 years respectively.

Or even more specific:

New Yorkers who are 70 saw their life expectancy increase 1.5 years, to 86.9, compared with 0.7 years, to 85.1, for the same age group nationwide.

I find such statements truly remarkable, since it is not at all straightforward that we can compute life expectancy statistics with great confidence and accuracy. A great deal of uncertainty enters the calculations in several ways, of which I would like to discuss a few: picking indicators, large prediction horizons, and lacking backtesting.

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