Saturday, 22 June 2019

17 Leagues, 6 Seasons, One Result

A few days ago, Joe tweeted the above message. 

The 17 leagues are comprised of the top two tiers of the Big Five leagues (England, France, Germany, Italy and Spain), plus Leagues One, Two and National in England, and the top leagues in Belgium, Netherlands, Portugal and Scotland. 

Not surprisingly, each league has its idiosyncrasies, not to mention varying over-rounds, and Joe followed up with: 

Before I get to last season, here are the numbers for the seasons for which we have Pinnacle's Closing Prices which are available at Joseph Buchdahl's site.

Some additional clarifications are that:

  • The seasons covered are the six seasons from 2012-13 to 2017-18
  • All Profit and Loss calculations use Pinnacle's Closing Prices
  • Any matches where Closing prices are missing have been excluded
  • 'Competitive' is defined as matches where no team has a 'true' win probability greater than 0.5
  • 'True' means after the over-round has been removed, i.e. the sum of the probabilities equals one. They are not truly true, but they are close.
First, the overall story, and I hope the picture is self-explanatory.

From the top, we have 40,524 matches and backing the Draw in each would have lost you 2.3%, which is basically the bookmaker's vig. 

There are faster ways of losing money than backing the Draw, but we can do better.

The next block shows the outcome of backing the Draw only in competitive matches, and the loss in this category is 1.4%.

Then I looked at matches where the two teams are within 25% of each other in terms of win probability, and finally at the relatively exclusive category where teams are within 10% of each other.

To keep Joe somewhat happy, 2018-19 is still to come, here are the numbers for Belgium and Netherlands:
As Joe suspected, these leagues do not follow the overall pattern, in fact the Netherlands results are the exact opposite of the overall results. Just back the Draw when a team is odds-on, and count the money, except that the market seems to have corrected since 2015, so this strategy is not recommended.

The only other league which is upside down like this is League One, although here we go from bad to worst with poor results across the board.
The other English leagues all follow the expected pattern, with the Premier League noticeably strong, something that will come as no surprise to readers of this blog.

For the Big Five leagues, the results for the top two levels are:

I'll update these results with 2018-19 in the next few days. 

Meanwhile, if anyone is interested in detailed results from any of the other leagues, let me know.

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