With my last article I introduced the concept of Goal Rating Models. I showed you that a very simplistic rating model won’t guarantee you profit. However, tweeking and adjusting your model will make it better in time. This is how you get closer to where you want to be. In order to do that, you need to understand the stats your model is based upon. In this case, we are talking about goal stats. To help you with this I wanted to present you one of the anomalies typical for the football market. Namely, the rapid increase of goals scored in the last rounds of the season in European Leagues.
Goal Stats: End of Season Frenzy
Today I share with you one of the interesting observations I have made when researching European goal data from the last ~20 seasons. As some of you might know, the average number of scored goals in the last rounds of the season increases dramatically for just about every major European football league (which is probably true for all leagues in general, although I don’t have data to confirm it). Have a look at the average number of goals per country for the last 15 rounds of the season. I have based those on the last 22 seasons, using the available data at football-data.co.uk.
You see there is a clear upward slope towards the end of the season. The increase is less pronounced for England and Scotland and more for the continental leagues. For Italy, Germany, France, Spain, the increase seems to start 9-10 rounds before the last one. Than it peaks in the very last round of the season when teams score the most. There might be different explanations for this phenomenon. Less motivation due to the season being settled, tired players, youngsters getting time on the pitch. All factors point in the same direction.
I got pretty excited when I found out about this anomaly. We know that more goals are scored in the second half of a football game than in the first. But it seems to be another universal rule that more goals are scored in the last weeks of a season. After finding that out, my first thought was to test the profitability of a strategy built around the finding.
Do the markets know about it?
I decided to omit England and Scotland from the test. The increase in goal scoring at the end of the season for those leagues was less profound. I wanted to restrict myself to the leagues with a story to tell.
Moreover, I noticed the increase starts around 10 rounds before the end of the season. Therefore, I tested a strategy backing the >2.5 goals at the maximum available odds for the respective league in the last 10 rounds of the season. I have calculated the results from the last 11 seasons. The data used was from football-data.co.uk. Here are the results:
The first letter stands for the country (Spain, Italy, Germany and France) and the number for the tier of the league, first or second. One can clearly see that from the 8 tested leagues the strategy would have been profitable only for Segunda, Ligue 1 and somewhat for Serie A. Moreover, it is striking how low the returns for the German leagues go in the last round(s). Especially considering that Germany is the country with the most profound increase in goals and the most goals in general as could be seen in the first graph. On the other hand, although France appears to be the league with the least goals among the tested, the profit backing overs there seems to be one of the higher ones.
Can you make a profit with it?
Despite the fact that for Segunda and Ligue 1 one can see a nice steady increase in profit, the strategy for all leagues combined seems to be a losing one. Whether it is worthy to try it for those two leagues alone you can decide for yourself.
In any case, it is a good example for how the bookmaker has incorporated a stats trend in the price before we even know about it. Therefore stats alone don’t tell us anything in the betting world. At least unless you look at them from the perspective of the betting odds. Still, if you dig deep enough, you can find a successfull betting angle and benefit from it.
Goal Stats: What are they good for?
Obviously, one cannot make a profit by betting every trend observed on a market. However, if you model a rating throughout the season, you should know about those anomalies. Otherwise you will weigh a goal at the end of the season the same as one at the beginning. However, obviously, those are not worth the same. A goal in the beginning of the season might secure you important points in the midst of a battle for the title or for avoiding relegation. A goal at the end of the season likely comes from a meaningless game, where everything has already be settled. Those are mostly only slightly more important than a regular friendly game. This, in turn, explains the number of goals scored in them. Obviously, not all goals are made alike and the Goal Stats show that.
If you want to use this information to build a Goal Rating Model, I strongly suggest to refer to my step-by-step guide on Building a Rating Model. It also wouldn’t hurt to check my last article for a practical example.
I am planning to publish a few more articles on interesting football stats. So, if this is what you are looking for make sure to follow me on Twitter or Facebook in order to be notified for new blog posts. Thanks for reading and see you around!