Our premise is a simple one: are goalkeepers any more or less likely to be left-footed than outfield players? And does this footedness vary between different counties? We will look at explanations for any significant differences in our data.
We need a database of current professional footballers, into which parameters are easily entered. For this, the Football Manager 2012 database is ideal. However, unlike with our earlier research on the England's best positions, our use of Football Manager does bring up a few problems with the data. We'll look at some later.
One of these problems is that Football Manager's database covers players from leagues all over the world. So to make our data more managable, we shall only look at players based in England, France, Germany, Italy and Spain.
The most important points are these:
- There are clearly more left-footed outfield players than goalkeepers.
- The percentage of left-footed outfielders stays consistently between 22% and 25%.
- The percentage of right-footed goalkeepers is far more variable than that of the outfielders.
- English and Italian goalkeepers are far less likely to be left-footed, whilst the Spanish are the most likely.
The main trouble with our data, which is clear to see, is that the amount of English players far outweighs the other four nations. This is due to how Football Manager provides its search results. Due to the size of its database, sometimes players do not come up in searches. This is partially to make the size of the game more managable for computers, but also it encourages the player to use his or her scouting network. Which is fine, but not very useful for our research.
We will now look at the reasons behind the three points raised above.
- First of all we need to decide whether it is the outfielders (average 22.4%) or the goalkeepers (average 9.4%) who are the furthest away from the norm. Studies show that up to 10% of the world population is left-handed. There is also a proven significant link between handedness and footedness. So we can assume that the world percentage of left-footed people is also around 10%. Therefore it is the outfielders who are bucking the trend.
- We might find the answer to this in the characteristics of the right hemisphere of the brain (which is linked to the preference of the left-sided limbs), and see if they have any bearing on footballing ability. However, there seems to be a more prosaic explanation: bias. In a traditional 4-4-2 (but also applicable to other formations), managers tend to play left-footed players in both the left back position, and the left midfield position. This means there are two positions guaranteed to be held by a left-footed in an XI. There will also be two held by a right-footer, obviously. Assuming there is no bias for the other 6 positions, the actual amount of left-footed players in an outfield of 10 players is 2.6, or 26%. This is far closer to the value we have arrived at. In modern football however, coaches have tended to experiment more with the footedness of their wide players, meaning there is less bias, which probably explains why none of our nations actually reach the 26% level.
- The higher variability of goalkeepers can in part be put down to the fact that their sample size is roughly 10% of that of the outfield players.
- Again, we could consider the characteristics of the hemispheres of the brain. However, not only is there vague and contradicting evidence on the subject, but it also puts us into the realm of psychology, which is just one step away from biology. So moving swiftly on, we again can look for a more reasonable explanation. The fact that the English and Italians have the least left-footed goalkeepers, whilst the Spanish have the most, is a good starting point. In both England and Italy, goalkeepers are just expected to stop shots, rather than to have any creative roles. In Italy this is because the libero traditionally does the playmaking from the back, whilst in England, no-one does any playmaking. However, in Spain, goalkeepers often are more capable with the ball at their feet, especially under the tiki-taka style pioneered by Barcelona, and copied by the pack. So then, there seems to be a correlation between the creative role offered to a goalkeeper, and the percentage of goalkeepers that are left-footed. It is a common footballing cliché that left-footers are more elegant (for example you never hear of someone possessing a "cultured right foot"), and perhaps there is some truth in that.
Outfield players are more likely to be left-footed than goalkeepers, by a surprisingly large margin. Additionally, the percentage of left-footed goalkeepers varies between different nations. Whilst some of the reasons behind these discoveries may lie in the domain of people in lab coats, there are also sensible, simple reasons behind it, too.
Even if this article hasn't unearthed any ground-breaking discoveries, it might hopefully also serve as an example of how to look at data objectively and rationally.
Football Manager 2012 - database of footballers based in England, France, Germany, Italy and Spain.
Wiki Answers - a concise explanation of what percentage of the world population is left-handed.
Wikipedia - statistics on laterality laid out in an easy-to-read manner. Shows the link between handedness and footedness.