Earlier this week I started to look at the issue of bias within the US soccer system based on a player’s height. While it was clear that
tall players are favored over short players, it wasn’t clear whether that was
true globally and to what extent. To do that, we'd have to look at other leagues around the world.

**METHODOLOGY**

I examined players playing within the league of their
nationality to remove the potential issue of a league transferring in a bunch
of short or tall players from abroad. It is widely accepted that height within
a specific region (like a country) is normally distributed. So, I found average
heights and standard deviations for 10 different nations in Europe to compare
the US to so we can see if this is just an American issue. By using standard
deviations, we normalized the data across nations to account for that
particular nation’s height profile so it makes sense to compare different
nations. For those who are unfamiliar with normal distribution and standard deviation
or need a refresher, click
here.

What I’ve done is created a category for players within one
standard deviation of the mean in each direction and then another category for
players who are more than one standard deviation from the mean. What we should
see is about 68% of players should be within one standard deviation from the
mean. We’ll call them “average players” in terms of their height. This was
pretty close to true across the leagues. Where it becomes interesting is when
we look at players that are more than one standard deviation from the mean.

Again, I will be using location quotients to compare the US
to the European leagues. Smaller values (less than one) mean there are fewer
players in that height group than should be expected. Values close to one mean
there are about as many players in that category as would be expected. Large
values (greater than one) mean there are more players in that category than
should be expected.

**HEIGHT BIAS IS PRESENT IN THE 10 EUROPEAN LEAGUES EXAMINED**

The results show that, pretty much across the board, there
is some bias toward choosing taller players (more than one standard deviation
from the mean). This shouldn’t be that surprising as there are obviously some
positions (mainly keeper and, to a lesser extent, center back) where it is
advantageous to have a bit of height. Interestingly, Portugal and Italy have a
pretty strong favor for tall players whereas Finland, Belgium, Austria, and
Sweden don’t seem to care all that much about player height.

**USA’S HEIGHT BIAS IS STRONGER THAN THAT OF EUROPE**

Alright, so many readers peppered me with questions
wondering about how USA stacked up against foreign leagues. Here it is: we have
a higher likelihood to see tall Americans in MLS than what is experienced from
these ten European nations, on average. On the flip side, we see a much lower
likelihood of short players in MLS than in Europe. If we combine all 10
European countries into a single group, we see that it is roughly three times
less likely to have a short player in the US than it is in Europe. Even with the inclusion of the relatively more tall-favoring leagues of Italy and Portugal, the USA had a higher concentration of tall players than Europe

Pretty
damning evidence that the qualities valued in the US soccer environment are
based more on physical characteristics than they are on soccer abilities.

In the next post in this series (likely sometime next week),
I’ll be looking at where exactly the short players get weeded out from becoming
pros in the top domestic league in the US.

Note: the leagues chosen for this examination were purely based on which nations had the necessary height data available and that I found.