Different ways of seeing stats
Marathon winners are getting faster. But don't be fooled into thinking this means distance running is in rude health, says Michael Blastland in his regular column.
When my dad ran his first marathon, it was considered a strange, almost deranged pursuit. Few tried. There was no Great North run. The mass participation we see today was unknown in the UK.
Meanwhile in the US in the late 1970s, Jim Fixx put on his trainers, lost 30 kilos, wrote The Complete Book of Running, became a jogging guru and helped start a boom. The boom came to the UK.
In 1981, the London marathon began, motivated by race-founder Chris Brasher's experience of the New York marathon. Since then, the London event has multiplied five or six times in size - from about 6,000 finishers to about 34,000 last year - and become the inspiration in turn of hundreds of thousands.
Martin Lel breaks the tape in 2008
Winning times today would have stretched the imagination of those who ran it 28 years ago. Faster by nearly 20 seconds in every mile of the men's race, and 30 seconds per mile in the women's race, the pace at the front of both the men's and women's races would feel to many spectators like a two-hour sprint.
The winner last year was within a whisker of two hours five minutes - astonishing. By many measures, marathon running has enjoyed a phenomenal boom.
But something odd has also happened, not in the headline performance of winners, nor in the steady increase in popularity.
To discover what's peculiar, we need to look deeper - at the distribution of times across the field. It's a good lesson that there's seldom a just one story - in this case, that winning times are being cut - for any lump of data.
The chart, right, shows how many people finished within certain times at one of the first London marathons, and again last year. These were not unusual races in their period.
What's striking is the strange disappearance of good runners. That's good runners, rather than great - those who are far better than most, but not world-class, the kind who would impress at club level.
In 1982, a time of two hours 40 minutes would have placed you 457th. Last year, it would have been good enough for 184th - this despite the huge increase in competitors.
Matthew Parris, the Times columnist and former MP, finished in 1985 in the best time ever by an MP - an impressive two hours, 32mins, 57 seconds, for 385th out of about 20,000. Last year, this would have placed him 83rd out of 34,000. The year before (a hot day, admittedly), his time would have been good for 46th.
Of course, the weather can make a difference and you would expect some variation anyway. But not of this order, especially given that the old-timers argue the course is quicker these days (corners smoothed, cobbles carpeted, etc). But whilst there is now a flood of finishers at four hours-plus, it's become no more than a dripping tap just below the top.
Mind the gap
I should declare an interest. My dad, close to two hours, 40 minutes at his best, was a keen runner for 50 years and competed several times in the London. He still watches every televised minute of every race and marvels at the winners. But he mourns the spaces between those who come after.
Demand for places is high
How does this affect the way we think of the health of the sport? We could say that road running, including the marathon, is best measured by how many take part. On that basis it looks vibrant. We could look at the times of the winners, or at Paula Radcliffe - for years the best female marathon runner in the world - and we could say that excellence thrives (although not for the best British men, who are off the pace.)
So does it matter if the equivalent of the bottom half of football's premier league, the good but not great, has all but disappeared? It might, if this is where champions begin. Or it might matter simply for its own sake.
Where have all the good runners gone? There should be several hundred people out there in the UK who could perform to a high standard, but don't. It could be that good runners are avoiding the glitzy, big ticket events. But road races around the country are not recording good times in the numbers that they used to be.
The London marathon is glorious. To complete it on any terms is an achievement. But where is the tradition that pre-dated the boom? It was a small part of British life, to train and race as hard as you could on the heels of the best, important only really to those who loved it. But they did love it and the data suggests that, ever so quietly and amidst all the success, a part of running is dying.
• It's only a pie, a humble pie, but pay attention: this matters. In a small but animated corner of Dataviz (that's the world of data visualisation to you and me), aficionados are hotly debating the pie chart. Some eager to kill it.
First in the blogs, then Seed magazine, then this week under the headline "Pie charts don't cut it" in the New York Times, the story is growing, or should we say rising? (NB: bad puns are mandatory.)
How can a mere pie excite such fuss? Because statistics are a tool, not an end in themselves. Stats, and all their paraphernalia of charts and maps and the like, help show the world, or they do nothing. And the point about pies, allegedly, is that they obscure data rather than clarify. There could be no worse crime - if guilty.
Stephen Few, of Perceptual Edge, offers a good summary of the arguments against - and also this image, among others.
See a pie, flip it up
His illustration, reproduced on the right, shows how the pie has become too humble for some, who can't resist the sort of graphics packages that invite you to jazz it up with 3D effects. But turn a pie on its side and it seems that people pay more attention to the leading edge than the surface. The relative angles and proportions at the surface - which are what matter - are obscured.
What's more, we're not good at estimating those angles even when the pie is flat. Show more than a very few portions in a pie and it becomes hard to compare one with another. Bar charts, say some, do it better.
Pies do have their defenders, but even they tend to dislike the 3D fad. And it's true of more than pies that people are doing zappy things with visualisation just because they can. Yet clever software doesn't necessarily mean better communication.
Dataviz has been discovering that statistical tools needn't look dull, but also that there's a difference between looking flash and working well. The pie, it's now argued by some, never did either.
Death to the pie - what do you think about this, and the running stats?
Add your comments on this story, using the form below.
Are the good runners not attending some other races which are cheaper, more fun, less pressure and they are actually in with a chance of winning? There is much more choice of where to compete than there was 20 years ago.
Bob Robert, Bristol
One of the reasons why the number of "good" runners is dropping is because there is less motivation to run for the sake of running. Many people use it to fund-raise for their favourite cause and enjoy the experience of being part of what is now a great British institution. It's taking part that counts for so many more than taking their time apart.
Harun Rabbani, London
Death to the pie chart? No, just use it properly, as with all stats you can manipulate to support whatever your argument is. Don't make it 3D or flip it. Keep it flat, and order the segments by size, start at 12 o'clock and work round clockwise largest to smallest - easy as pie!
Many good runners prefer off-road events such as fell or multi terrain races. Part of the reason for this is difficulty in obtaining police and local authority support to stage road races and the aggression, impatience and dangerous driving of a minority of car drivers when road races are staged. Another explanation might be in the time required to train to a good standard. Finding the time to get out and put in 100-mile weeks as well as hold down a job and fulfil family obligations is far more difficult now than it was 30 years ago.
H Pearson, Leeds, UK
Originally it was mainly club and other regular runners who applied. Today, with more applying than places, and the vast majority of the increase being down to fun runners and people who have only started running to do the one marathon, inevitably the "good" runners are denied the places given to the masses today.
Luke Senior, Dewsbury, UK
Could it not be the case that the "good runners" are now trapped in the start with the mass of fun runners, whereas the elite runners, say sub 2h15, occupy the front for the quick get away? What about the increased amount of marathons available to run these days - does that not dilute attendance at London? And what about the rise of other athletic sports such as triathlon? Maybe the good runners have diversified. I don't doubt that the good runners are out there but the London marathon has become a charity fundraiser for the masses or an elite Olympic qualifier, leaving little space for them.
John Turner, Douglas Isle of Man
I'm not a huge fan of pie charts, but they have their (limited) place. What should be outlawed are 3D charts and graphs which entertain the eye but obscure the message - this goes for 3D bar charts too. What might make people happier about their charts is if they can easily apply pre-defined colour schemes rather than using the default colours in Excel, or faffing about changing each colour manually, or loading some nice colour scheme from another file (my preferred lesser evil).
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