Some time ago, Chris Anderson and I had some discussion about the importance of being tall in modern football. He blogged about some statistical Fingerübungen of mine. In some of the charts I produced I linked average national body height in a society with the performance of the respective national teams. Chris himself seemed to be ambivalent about this idea, since he rightly pointed out case that run counter to this idea. On the Club level, most prominently, Barcelona is a well-known example of small, agile midfield players instilling terror in La Liga and the Champions League alike. Since football statistics is a larger than life affair, it is time to resume the issue and summarize what we know about this important matter, once and for all.
Football is a democratic sport. This is perhaps one of its secrets as a global success story. Famous players range from short players like Lionel Messi (169cm), to giants like Zlatan Ibrahimovic (195cm). They may be thin like Peter Crouch (75kg/203cm) or big like Hans-Peter Briegel (79kg/187cm), a German player of the 1980s whom the fans affectionately called ‘steam roller’. Short people, as well as short teams can surely compensate missing physique. They can be faster, more agile, more nimble, or simply better organized. The German women’s national team learned this painful lesson in its home world cup 2011. They lost their quarter finals against the Japanese team, the future champions, despite the fact that, on average, the German players were 10cm taller than their Japanese opponents.
Nonetheless, size, or tallness, more precisely, does matter. Kristof Van Hout is reportedly the tallest professional football player in the world with a body height of 6’10” (208cm). The goalkeeper currently plies his trade for K.V. Kortrijk in the Belgian Pro League after moving from better-known Standard Liege. Tallness is not always important, but in some positions it is crucial. Goalkeepers and central backs are perhaps those positions where it matters most (yes, I do know that Iker Casillas is ‘only’ 185cm). Yet, the ‘arms race’ in body height might also make it necessary for certain strikers to be tall, especially for those teams that like ‘hoofing’ the ball.
Indeed, studies have found tallness to matter, even if not always in ways expected. Some studies have found that taller players are more likely to get booked. Yet, even if it is no general rule, very often, the physically stronger teams win (in the data I collected it seems to increase the odds of winning quite considerably). For example, the Brazilian male team who won the world cup in 1994 was incidentally also the tallest team. Brazil is also a good example to show why other countries persistently ‘underperform’. There are many reasons why certain nations are less successful in football. Soccernomics mentions factors such as size of the population or GDP per capita. Past successes might also play a role, although this just shifts the puzzle to the past. But for similar levels of GDP or population, these explanations don’t bite. In these cases, physique might make the difference.
Figure 1 shows this. The figure plots national averages in body heights (Wikipedia, several entries per country possible) and success in football. Success in football is difficult to measure, but for purposes of convenience I just took the FIFA coefficient which continuously counts looses and wins of national teams weighted by ‘importance’ of the match and the opponent. We see that there is a big difference between Mexico and Brazil when it comes to body height. Mexican history saw a completely different inflow of migrants than Brazil. This historical legacy is still visible in a national average that is some 8cm lower than the Brazilian average. Moreover, the variation in body height among Brazilian men is arguably much higher. This is crucial: it does not do harm to have some short people in the midfield or as full backs, as long as you find enough tall central defenders.
The figure also may explain the shortcoming (no pun intended?) of many South Asian teams. And these teams are aware of the problem. Some years ago the Cambodian national team introduced a minimal body height of, if I remember well, 160cm. It is not the only example. As the size of the goals has remained constant since the introduction of the game, but many peoples, especially in rich countries, have increased in size for the last 100 years, the gap has increased.
The gap is not equally decisive everywhere. For instance, if we look at the same relationship for female national teams, the relationship is still visible, but markedly weaker (figure 2). This is probably related to the fact that female professional football is still a nascent phenomenon and not known to the same degree across the world. In male football, where scouts penetrate every last corner of this globe to look for the latest Didier Drogba or Shinji Kagawa this is much less of a problem. Here professionalism tends towards the physical limits of the game. Indeed the relationship of figure 1 is stable, statistically speaking, if one tries to ‘controls’ for the other determinants of success mentioned above.
Similar things apply to the club level. Take the most successful German club, Bayern Munich. Over the last 50 years the average height of the players increased by some 5cm (data from fussballdaten.de). By the way this is less than the increase in the overall population. Professional football players were always above the national average. But the rising trend is visible, and even more so among goalkeepers and central defenders. Another fact is visible in figure 3. The variability of body height has more than doubled from some ca. 8cm to 18cm. Balon D’Or winner Frank Ribery (170cm) can still be the pivot of the Bayern machine, as long as its goalie, Manuel Neuer, is 192cm.
All in all, size does matter in football. Next time inhabitants of short nations see their teams loose they should give their boys some credit or growth hormones. Even better: make your people healthy.