ANALYSE THIS: Is the PL table telling the truth or lying?

FOOTBALL – In November 2011, the then coach of FC Twente Co Adriaanse coined the term rangjournalistiek (best translated as rank journalism) referring to his opinion that the league table during the season doesn’t reflect how good or bad the competing teams are. At the beginning of this season, Infostrada’s Head of Analysis Simon Gleave went in search of different methods to try and quantify this.

The method

One of the simplest methods to use is simply to compare the results this season with those achieved in exactly the same fixtures as last season. In order to have a shorthand to describe this, let’s call it the ISG coefficient. Firstly though, there is a problem to solve – what do we do with the promoted clubs? Quite simply the best promoted club replaces the best relegated club, second best replaces the second best etc. So, last night’s West Ham United v Stoke City match is compared to last season’s Wolverhampton Wanderers v Stoke City fixture. When I was looking at this earlier in the season I discovered that Chris Collinson at Sky Sports was doing the same. He has jokingly told me that I am the only person who can check that his numbers are correct.

The thinking
The thinking behind this is that teams retain a certain ability from season to season and this is reflected when looking at the points they achieve. There is a positive relationship between points in one season with points the following season. By treating the promoted teams as we do, we weaken this relationship a little but by doing so we keep things simple and it allows us to judge how those promoted teams are performing in relation to their initial goal of survival.

By comparing fixtures in this way, we can do the following:
– Identify whether a team is really doing better this season than last and quantify this.
– Assess whether they are on target to finish in a better or worse position in the final league table.
– Compare promoted clubs’ progress with their relegated counterparts from last season

Click here to interact with the graphic

The graphic above shows the current league table on the left, the ISG coefficient for each club in the first bar graph and a projection of points at the end of the season based on all remaining results being the same as last term.

Early narratives
Even this very simple assessment has illustrated that some of the early season narratives in the Premier League were worth challenging.

– Everton’s good start was not reflected here as their results were never more than two points in total better than last season.
– Manchester City’s results in comparison to last season have been consistently better than Manchester United’s.
– Sunderland have never had a negative ISG coefficient this season.

West Bromwich Albion
Looking at the projected final table, a clear top-5 has already emerged and is likely to be similar to last season as one might expect. West Bromwich Albion’s fourth position looks impressive in the current standings but their ISG coefficient is only +2. Their victory against Chelsea on Saturday was simply a repeat of last season’s result and to finish much higher than in 2011/2012 their results will need to improve a lot more than they have so far in comparison to last term.

All models are wrong
Of course, this is a very simple model and the projected final standings rely on as much data as possible to be accurate. However, as statistician George Box said, “essentially all models are wrong, but some are useful”. This one certainly belongs amongst the useful ones and we will be revisiting this throughout the season, not only for the Premier League but also for other competitions.


4 thoughts on “ANALYSE THIS: Is the PL table telling the truth or lying?

  1. Pingback: *Official* English Football Season 2014-15 - Page 174

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  3. Pingback: The Times’ Bill Edgar vs other models | Scoreboard Journalism

  4. Pingback: - Hele Norges fotballportal

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