Which team is currently the strongest of the Eredivisie? Ask this question to a fan, a manager, a pundit and an analytic football blogger and you will probably come up with four very different answers…
The fan would probably not understand the very fact that you’re asking this, particularly at this time of the year with the Eredivisie that just finished. Obviously, it would be Ajax, duh. They just won the league for the third time in a row, didn’t they?
The manager would maybe find a bit more nuance and say that this season Ajax was just a bit stronger than PSV, particularly near the season end, and Ajax’ 3-2 win in Eindhoven put them in the driver’s seat towards the title.
The pundit would push Ajax forward as the strongest team, and immediately start feeding you correlations disguised as explanations as to why Ajax is stronger than the other teams. Ajax is building a ‘successful revolution’, the team plays a ‘recognizable style of football’ and they allow home-grown talent a decent shot in their first team.
The analytics blogger would probably take most time in answering this question, and to be fair, if you would ask me, I would not be quite so sure whether to pick Ajax or PSV.
We’ll now look into the important question of determining the best team in the league, based on a few assumptions.
Firstly, playing 34 football matches is a poor way to determine which team has the most quality, as was demonstrated quite elegantly by @penaltyblog.
Secondly, luck has more influence in football than it’s generally credited for. If skill would be the prime factor involved, wouldn’t betting companies be capable of calling the correct winners of football matches in more than the 50% to 55% of cases that they do now?
Imagine this thought experiment…
It’s August 10, 2012 and the 2012/13 Eredivisie is about to start in Tilburg, where newly promoted Willem II is about to host NAC Breda. Just prior to the kick-off, we press an imaginary ‘save’ button and quickly fast-forward to May 12, 2013, the final Match Day.
Here we reload our ‘save game’ from August 10, 2012 and we run the same season again. And again, and again and again… A million times.
Using bookmaker odds as an estimate for team strength, we can do just that. After all, bookmaker odds can’t be too far off, otherwise we would be allowed an easy occasion to make some cheap money exploiting them. And if we would all do so, the odds would get corrected quickly. Admittedly, the odds are never perfect and there is quite some evidence that strong home teams will be overestimated, but only slightly so.
Using some recently acquired skills in R we can run a simulation of one million seasons in just under four minutes, so let’s go straight to the winners…
The 2012/13 Eredivisie, as we can see, was more of a two horse race than it was held for. On the other hand, this simulation also turns out that only two teams – now relegated VVV and Willem II – did not manage to win a single simulation out of a million runs. All other teams, had at least a one in a million shot at the Eredivisie title, if we use bookie odds as an indicator for their chance of winning matches.
Process versus results
This should be an important piece of information for people in charge of professional football clubs. The old adage had always been that ‘the winning coach is always right’, and going by the recent laudation of Frank de Boer as up and coming manager, that adage is presently as strong as ever. Results dominate our image.
In fact, it’s the underlying process that should get our attention. Give me a manager that substantially increases my team’s chances of winning the league, rather than a manager that wins the league without an underlying improvement of performance. Professional football organizations that appoint managers on the basis of results only, run a serious risk of dumping a manager who was developing the underlying process well and trading him for a manager that has experienced just a bit more luck.
The separation of process and results will be an important goal at 11tegen11 during the upcoming season, and using simulations will be a crucial tool to do so.
Some of you may have noticed a decrease in the frequency of new articles on 11tegen11. I can assure you that this is a temporary thing and activity on 11tegen11 will pick up over the summer. It is in part due to the start of Dutch Volkskrant blog ‘De Zestien’, where you are more than welcome to read articles by @SimonGleave, @Tijsrokers, @MichieldeHoog and myself. I hear Google translate does a decent, and on occasion surprisingly entertaining job in making the Dutch articles accessible to foreign readers.