epidemiologista

Trying to make sense of nonsense

Category Archives: Sports

Dutch Dominance & Sankey Diagrams

I haven’t been writing a lot lately – partly because I have been busy finishing up my PhD thesis, partly because writing said thesis has drained all the joy from writing for me (hopefully temporarily). So instead, I’ve been tinkering with data and graphs, which led me to discover Sankey Diagrams earlier this week. They’re pretty neat, and easy to put together in Excel with the spreadsheet over on Excel Liberation. Unfortunately, they use some Javascript that WordPress blogs don’t allow, so for now, I’ve just taken some screen shots of the diagrams I’ve been putting together.

If you’ve been following the Olympics in Sochi a bit (like I have), you might have seen the occasional person in orange fly by. Us Dutchies are not particularly well equipped when it comes to the winter Olympics, but we usually win a couple of medals in our favourite sport: long track ice speed skating. Sure, we’ll lose out on the occasional medal because some American inline skater decided their sport wasn’t going to turn Olympic any time soon, but we win our fair share. Until Sochi.

With our previous record being a total of 11 medals at the Nagano winter games in 1998 (all speed skating), the aim for the 2014 Games was to win about 9 medals. We’ve won a spectacular 22 so far, all but one in our favourite sport: speed skating (and the one not in speed skating, we won in short track speed skating). We’ve done so well, we’ve won almost 75% of speed skating medals:

Olympic medals - long track speedskating

Sochi Olympic medals in long track speedskating

We’re doing so well, that we’ve even managed to make it to the top 10 of the overall medal table*:

Sochi overall medal table

Overall Sochi medal table as of 19/02 showing medals won by each country, and sports they won them for (this was supposed to be a fancy Javascript enabled graph that would allow you to hover over the lines to see where they’re going, but alas, WordPress doesn’t allow Js scripts).

As a small country (we like to emphasise that we’re small when we lose, and even more when we win), we’re doing pretty well for ourselves. So you might think our skaters would be happy with their medals. Well not all of them (prepare for Tumblr style end of post).

Disappointed Dutch Olympic silver medallists:

Ireen Wüst – didn’t manage to defend her 1,500 meter gold medal she won in Vancouver (though she has won a gold medal on the 3km, and two more silver medals on the 1,000 meters and 5km) – Picture by de Volkskrant

Sven Kramer (left) – did not win his favourite distance: the 10km. In Vancouver, he missed the gold medal after being disqualified for forgetting to change lanes. Won a further gold medal on the 5km (picture by het Parool).

Jan Smeekens – was 0.012 seconds removed from an Olympic Gold medal (picture by schaatsupdate.nl)

Koen Verweij – 0.003 seconds short of an Olympic gold medal on the 1,500 meters (picture by schaatsen.nl)

*As of 19/02 – will update results at the end of the games

It’s a man’s world: gender imbalance in sports reporting

Sport is a man’s world. At least that’s the impression I get when I watch any. Reporters are (mostly) men, reporting on (mostly) men, except where beach volleyball is concerned, and then it’s still seemingly just for men to look at. Not surprising then, the Olympics were a breath of fresh air this summer. Everyone cheered when Jess Ennis finally won that gold medal, when Lizzie Armitstead was the first Brit to step onto the victory stage, and when the aquatics centre exploded after Ellie Simmonds made it to the finish first. After all those Olympic success stories, you might expect women to get a bit more attention on the BBC’s sports pages*.  However, as this tweet in @EverydaySexism’s timeline made clear, it doesn’t seem to have happened. Out of three months of sport’s coverage highlighted on the BBC’s Facebook page, only 5.4% of posts covered women’s sports. Abysmal seems an appropriate description here.

So how does the sports coverage measure up? The BBC Sport’s Facebook page highlights only some of its sports coverage, so there is a chance that women are covered, but they just don’t make it onto the Facebook page. Unfortunately, the Beeb isn’t very good at archiving their sports material, so apart from collecting data from Facebook, there doesn’t seem to an easy way to retrospectively see how often they covered women in sport**. Luckily, the Dutch public broadcaster – the NOS – does archive all their sports coverage by date on their website. And to make this international comparison complete, I also added a bit of Belgian (or rather: Flemish – my French isn’t what it used to be) sports coverage by adding their public broadcaster’s sport Facebook page (Sporza). For all three broadcasters, I gathered all their (highlights of) sport coverage for the whole of November.

So how do these three countries’ public broadcasters compare on reporting on men and in sport? Well, not very good. The BBC had no posts relating to women’s sport at all, while the Belgians only specifically covered women in sport once: a story on professional female cyclists appearing in a ‘sensual’ calendar. The Dutch, who contributed all stories not just highlights, score ever so slightly better. Though with only 11% of articles covering women, it’s hardly an improvement.

Public broadcasters' articles on sports

Public broadcasters’ articles on sports

But hey, what about confounders, things that might mess this quick analysis up? Maybe there’s one particular sport (let’s call it football) that’s skewing these results. Women’s football is famous for its lack of coverage, so maybe these nations’ football obsession is partly to blame for the lack of coverage of women in sports? Well, football does make up the majority of posts and articles, especially when looking at Facebook highlights.

Sports reporting - sports by country

So what happens if we just ignore football (something we ought to do more often)? Well, nothing much really. Women are still massively underrepresented on the sports pages, with 1 in 5 articles focussing on them at best, and even fewer articles mentioning both men and women.

Ignoring football, there is still massive gender bias

Ignoring football, there is still massive gender bias

What about those other sports? The UK and Belgian Facebook highlights didn’t include too many sports besides football or other male-dominated sports such as Formula 1. The Dutch broadcaster did include a lot of other sports though, so surely there must be some sports where reporting is more equal?

And yes: there seems to be some good news: for skiing, swimming and long-track ice speed skating*** gender balance looks a lot more promising with generally equal coverage. There are also some more disappointments though with cycling and tennis, which I expected to be more balanced.

Coverage of men and women by sport (all the more reason to like long track ice speed skating!)

Coverage of men and women by sport (all the more reason to like long track ice speed skating!)

Especially for cycling I personally expected better. Mostly because coverage tends to be biased towards people or teams who win, and the current women’s world and Olympic road cycling champion happens to be Dutch. The men in Dutch cycling on the other hand, have hardly anything to boast about this year, apart from being mentioned in relation to Lance Armstrong just a bit too often. Still, only one single story covered women’s cycling.

Broadcasters aren’t the only ones to blame though. Especially in the case of road cycling, there just isn’t that much to broadcast. While the men will be plastered over the television every weekend from March till September, there are just two women’s races that tend to be covered live on Dutch television: the world championships and the Olympics. For almost all other classic road cycling races such as the Tour de France, Paris-Roubaix or Milan-San Remo, there are no races for women. The men race, amateurs often get a chance to go on the course, and there might even be a special race for under-23s, but not for women.

This seems to lead to a vicious circle: there are fewer events for female athletes, leading to less media coverage, which in turn makes women’s sport less interesting for sponsors who’d like some air time by plastering their logo onto some sporty people, resulting in less money to actually put on those events.

It has to change. Sports like skiing seem to make it work. Lindsey Vonn is so far ahead of the rest of the field that she has asked to compete with the men. She’d stand a fair chance. A mixed gender relay was introduced in swimming so men and women can compete together rather than having separate events. We loved seeing our women competing in the Olympics as much as we did the men. Now let’s get them back on their screens.

 

*And after the amazing Paralympics you might also expect some more attention for those athletes. However, the BBC Disability Sport page still seems to be stuck in September.

**Do let me know if I missed something obvious – the overwhelming onslaught of male pheromones and yellow banners screaming off the page may have messed up my brain.

***i.e. the greatest sport on earth: athletes reach speeds of up to 70km/h (43mph) while basically wearing nothing but razor sharp knives under their feet and a tight fitting body suit – no helmets or any other type of protection is used. Its popularity is sadly restricted to Holland and Holland alone – though we like it that way as we can scoop up lots of Olympic medals without anyone else noticing.

In which the Dutch try and keep their cool

Elfstedentocht

Picture courtesy of Art Rock (Hennie)

If you have been around any Dutch people for the last couple of days, you might have noticed something strange. Whenever the temperatures drop below zero degrees, the Dutch tend to get a bit excited. After all, we are known to be a nation of ice skaters. But it’s not until it gets really cold, and for a longer period of time that we tend to get really aroused. Other nations observe us in horror as we switch into gear: it might be the year of another Elfstedentocht.

The Elfstedentocht, or eleven city tour, is the stuff of Dutch legends. Where the British have King Arthur and ‘1966’, we have this – despite the Americans’ best efforts to sell us Hans Brinker and his dike-plugging abilities. The tour consists of 200km, or 125 miles, of ice skating across the Northern region of the Netherlands known as Friesland, visiting 11 different towns and cities, often in gruelling weather conditions. As the ice has to be at least 15cm thick along the entire route, the Tour of Tours doesn’t happen very often: a mere 15 times over the last century, with the last rendition on 4 January 1997.

With the ice mega-marathon being so rare, speculation on whether there will be another one, and when exactly it will happen has become a sport in its own right. The Royal Dutch Meteorological Institute (KNMI) prides itself on being the only institution in the world with an official ice growth model. An example of the model’s predictions is shown in Figure 1. On the Y-axis, numbers above 0 represent water temperatures, while sub-zero figures show predicted ice thickness. The bottom graph shows predicted air temperatures. The model uses data of a high resolution (specific ‘weather’ data for a 16×16km grid), represented by the red line, and data of a lower resolution (using a 32×32km grid, the blue line) to predict ice thickness given 50 slightly different scenarios (the green lines).

Ice thickness prediction

Figure 1: Predicted ice thickness in the Netherlands, as of 8 February 2012.

Looking at these graphs, things are starting to look pretty good: ice thickness is where it should be, and the big freeze seems to have settled for at least the end of the week. Reason enough for the ‘rayonhoofden’, 22 regional ice managers, to gather for a meeting for the first time in 15 years last Sunday. However, as George E. P. Box put it: all models are wrong, the practical question is how wrong do they have to be to not be useful. Although the Dutch ice growth model is pretty sophisticated, taking factors such as wind chill and measurement uncertainty into account, it only models ice growth for 2-meter deep stagnant water in central Holland. As you might imagine with a 200km long route, not all of the waters and canals abide by that assumption.

Although a large part of the route is covered by the much desired ‘zwart ijs’ (black ice or smooth, hard ice), there are still holes in some places, caused by anything from fierce winds, to geese and snow. But with still half a week of freezing temperatures to go, insufficient ice quality can be dealt with. Ice transplantations, in which ice gets dumped into ice holes to encourage them to close are in full swing, and even the army has been called in to sweep snow, which can act as insulation, from the ice on the route.

The Dutch are desperate for an Elfstedentocht. The tour is already a rare event, and with average temperatures predicted to climb over the 21st century, the prospect of seeing thousands of ice skaters race across the canals of Friesland seems ever further off. The next couple of days will be vital. The Dutch will try and keep their cool, but whether it will be enough for the Elfstedentocht only time will tell.

Elfstedentocht probability

Figure 2: Model for relative probability for an ‘Elfstedentocht’ (ice thickness > 15cm) in the 21st century. ‘Relatieve kans’ = relative probability Red line: IPCC highest predicted temperature increase White line: IPCC mean predicted temperature increase Black line: IPCC lowest predicted temperature increase

Beware of the tweeting cyclist

Tour de France - Grand Depart

Which of these riders will be the next to get up close and personal to the asphalt? Picture by Laurie Beylier

Written for Significance

 

In the lull between the end of Wimbledon and the start of the football transfer window, two all-time favourites of the British, one of the most magnificent sporting events of the year takes place: the Tour de France (TdF). Unfortunately, it also appears to be one of the most underrated events, by the British at least. It might have something to do with France being the sole centre of attention for three whole weeks, the popularity of track cycling (even though road cycling can ride in circles around the track variant, very big circles where the TdF is concerned) or the lack of a British Tour de France winner. But with a rider like Mark Cavendish and his ability to actually win – as opposed the ‘cursed’ British tennis players – the spectacle ought to be at least as appealing as the Wimbledon finals.

One feature that does seem to grasp the attention is the spectacular falls that are bountiful in La Grande Boucle. The first week has been notorious for years: traditionally, it is filled with flat stages and the just under 200 riders are all but too eager for some early results in the race they have had their eyes on all year. This year was off to a maybe even more nervous start than normal as there were more flat stages before the riders reached the first real mountains: the Pyrenees. Moreover, the weather wasn’t exactly what you’d expect during summer in France, and wet roads and nervous riders are not the best combination. This shows in the number of riders leaving the Tour early, mostly due to injuries sustained by falls.

Figure 1: Proportion of riders still competing in the Tour de France by stage

Figure 1: Proportion of riders still competing in the Tour de France by stage

That some stages can be particularly dangerous is shown in Figure 1. The line depicts the proportion of riders that remain in the race. During stage 9, a very rainy day with a couple of small, but tricky hills, no less than 8 riders had to leave the race injured. Even more fell but managed to carry on, among whom were the victims of the most spectacular fall: Johnny Hoogerland and Juan Antonia Flecha who were driven off the road and into barbed wire by a car trying to pass them. Accidents like this can happen of course: in the past, riders have had to leave the race after collisions with anything from dogs, motorcycles to not-so-innocent onlookers. However, there might be a trend as to what sort of riders are more likely to get seriously injured. Maybe it’s the younger, less experienced riders who don’t know what to expect? Or maybe the opposite: the older riders who are defying age and maybe better judgement in trying to finish on the Champs-Élysées one last time?

There only one way to find out: throw some data and analyses at the problem. Wikipedia helpfully has a list of riders of this year’s Tour with some additional data on each rider such as country of origin, team and, more importantly, their age. After the first 10 stages, a trend does appear to be developing: older riders seem to be more likely to leave to the Tour: each year increase in age, increase the risk of leaving the Tour by around 10%. However, the difference is not statistically significant and with just 20 riders having been eliminated at this point, this finding is likely to be due to chance. The same holds true when looking at number of previous Tour entries; and there is no one ill-prepared team whose riders have a tendency to get up close and personal with the asphalt.

It gets more interesting when you add Twitter to the equation. Sporza, a sports channel from Belgium, has compiled a list of tweeting riders and a quick analysis learns that these social media savvy men are much more prone to fall: their risk of leaving the Tour early is over twice as high as their non-tweeting colleagues. The effect just fails to reach statistical significance, so when looking just at the numbers we can’t be sure whether we should issue a warning to be on the lookout for all tweeting cyclists.

Survival analysis: riders surviving in the TdF by Twitter presence

Figure 2: proportion of Tour de France riders still in the race, by Twitter presence (mind the change in the values on the y-axis compared to the first graph)

The picture changes when we take the whole Tour de France, so flat and mountain stages, into account: Twitter loses its influence on the riders’ capability to remain on their bikes, but age does seem to explain away a part of the apparent randomness in the quitting behaviour. It’s only a very small effect, but the older riders do seem to be a tiny bit more likely to give in to injuries and fatigue. When taking a closer look at the Twitter behaviour of the riders, it becomes apparent that the younger riders are just a bit more likely to be on there, thus explaining the initial result. If anything, this shows that if you include enough nonsense in an analysis, you will find something. With Twitter and Tour de France it’s obvious that there is no real cause and effect relation, in trials and medical research it might be a lot less clear.

So should we beware of the tweeting cyclist? Perhaps not, but as it just so happens that the entire top three in the overall classification has a Twitter account, you might want to keep an eye out for them.