The Weighting Game.

Shot counts verses goal counts as a predictor of future performance is a debate that that is being fought out not only in football, but also in hockey. Sample size is at the heart of the issue. Goals are obviously more important in terms of who wins th… Read more ›

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Breaking down the Ballon d’Or shortlist: Messi, Ronaldo and Neuer

ESPN FC’s Paul Mariner and Alexis Nunes weigh in on the Ballon d’Or and FIFPro Top Forwards shortlists.

The three finalists for the FIFA Ballon d’Or were announced on Monday: Lionel Messi, Manuel Neuer and Cristiano Ronaldo. Here’s a look at the stats that made them great in 2014 and the possible accomplishments that lie before them…

* After one goal in eight previous World Cup games, Lionel Messi scored four times at the 2014 World Cup and won the Golden Ball as the tournament’s best player. He’s had 52 goals in 62 games for club and country this year, also adding the La Liga and Champions League… Read more ›

Massey Ratings For Football Part One

Introduction We all know the league table can lie and one of the common causes of this is strength of schedule. Take Southampton, at the time of writing they are currently second in the Premier League twelve matches in yet still haven’t played Chelsea, Manchester City, Manchester United or Arsenal. Without wishing to be dismissive [...] Read more ›

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Why Uttoxeter Probably Isn’t A Hotbed of Swimming Talent.

Occasionally the newspapers publish stats based articles that do not relate to sport, but do serve to highlight some of the dubious assumptions that can be made from such studies.
In the run up to Christmas, a raft of newspapers, including the Daily Telegraph reported that the drink driving capital of Britain was Llandrindod Wells, a small rural town in mid Wales.

LW had over the last 12 months 1.98 convictions per 1,000 drivers, second to Blackpool with 1.85 such convictions. After establishing the drink driving hotspot, a couple of reasons were then devised to explain the results, lack of public transport and a belief that an offender will not be caught in a rural setting, for example.

However, studies comprising very different sample sizes inevitably lead to conclusions that may fail to represent the true picture. Most famously a study decided that small schools are inherently better than large ones because they appeared in disproportionate numbers at the top of a performance table and is quoted in Daniel Kahneman’s book “Thinking, fast and slow”.

In short, sometimes samples are too small to come to a reliable conclusion.

LW has a population of just over 5,000. If the town follows national trends around 80% of the population will be able to legally hold a driving licence. So, 1.98 convictions per 1,000 drivers implies that 8 cases of drink driving were successfully caught and prosecuted in LW over the previous 12 months.

If we imagine that one such case went undetected. Now LW has a conviction rate of 1.75 per 1,000 and they fall to 4th in the table. Blackpool is now top and it may seem that seaside towns lead to drink driving.

If convictions drop to 6 LW fall to the middle of the roll of shame with entirely unexceptional conviction rates per 1,000 drivers. However, two extra cases added to the actual total catapults the town to 2.5 cases per 1,000, well above the next worst, Blackpool.

So it is possibly the size of LW population that has contributed to making them a headline in the national press. Blackpool, in contrast has around 118,000 drivers and the conviction rate is much less susceptible to large changes occurring in that headline rate because of small numerical changes in convicted or non-convicted cases. Blackpool has probably prosecuted around 280 drink drivers.

Percentages derived from small sample sizes can bounce around if the raw number of cases alters by just one or two.  Just as small schools can be shown to be the best, as in the study quoted in Kahneman’s book, they can also quickly become the worst if just a handful of students produce poor results rather than excellent ones.

To keep the blog sports orientated, let’s use this dubious method to “prove” that Uttoxeter, population 12,000, a small town on the correct side of the Staffordshire/Derbyshire border is a hot bed of swimming world records.

Around 12% of the population are in the age group that would typically hold a world swimming record. So Uttoxeter has around 1,400 potential champions. They currently have one actual world record holder, Adam Peaty (100/1 to be Sports personality of the Year, but don’t let that put you off voting for Adam).

Therefore, Uttoxeter has 0.7 world record swimmers per 1,000 likely candidates. This of course would double if we made the conditions gender specific, but it is still good enough to give it the best headline rate in the country.

So Uttoxeter can be shown to be the place for swimming excellence, but only by using percentages applied to small sample sizes which obscure, rather than illuminate the less startling reality of the situation.

Sadly, it is  flawed conclusion, based on the exploits of a single outstanding swimmer, especially as the town doesn’t currently have a swimming pool!

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Five Aside: Messi sets second scoring record in a week with hat trick

Barcelona’s Lionel Messi becomes the Champions League all-time goals leader with 72.

Lionel Messi scored his 72nd, 73rd and 74th Champions League goals Tuesday against APOEL Nicosia in Cyprus, breaking Raul’s all-time record of 71 goals in the tournament.

Here are five stats on the Argentine’s scoring record.

* The hat trick scored against APOEL was Messi’s fifth career Champions League hat trick, two more than any other player in tournament history.

* In the 47 Champions League games where Messi has scored at least one goal, Barcelona is 38-2-7, losing to Celtic in 2012… Read more ›

Is the Sloan Sports Analytics Conference still worth attending?

I have been attending the MIT Sloan Sports Analytics Conference since 2010, right at the time that the Conference was transitioning from an intimate meeting of professional sports insiders and academics to a slick and polished cultural event.  As happens every year at this time, I receive notifications from the organizers of the conference that encourage […] Read more ›

Who plays and gets paid more? Player participation in MLS 2014

I’ve been working on front-office efficiency figures for Major League Soccer in 2014, and while I’ve been putting those results together I wanted to see what kind of information could be shown with the data that I have.  One idea that came to mind was to take minutes played data of MLS players in the […] Read more ›