Six days left before the start of the World Cup 2018, where the hosts, Russia, face Saudi Arabia in the 1st match of Group A. At this point, it would be interesting to analyze the impact of some environmental factors on the performance of the countries participating in the biggest sports event in the world. Every detail is significant at this stage of the tournament.
The main purpose of this research is to find the interaction between several environmental factors and their total impact on the performance of international players, and specifically African ones. For the sake of this analysis, some in-game aspects, such as solo runs, were evaluated under different conditions, so that the extent of their effect could be quantified.
The wait for the FIFA 2018 World Cup is nearly over with only a few days left to go until the tournament starts. Apart from the in-game characteristics of each country, several out-game factors, such as weather conditions, are considered to be game changers and even have the ability to define the final result of a match. In the current research, efforts have been made to analyze the effects of such factors on the performance of African Nations.
DATA COLLECTION & METHODOLOGY
Data was collected for African countries participating in the FIFA 2014 World Cup Group Stage in Brazil. Information consists of weather conditions, and more specifically, humidity levels, wind speed and ambient temperature.
Regression analysis was used in order to explain the correlation between the above mentioned factors and some specific characteristics of the teams’ style of play. For this reason, not only linear regression, but also, parabolas and polynomial fitting up to 3rd order were used.
Total shots were normalized based on the ranking difference of the two countries.
RESULTS & DISCUSSION
I. WEATHER CONDITIONS
Initially, it would be interesting to evaluate whether specific weather conditions have a toll on the style of play of African countries. For that reason, weather is classified into three categories:
Firstly, the possibility of an African nation gaining at least a draw during the 3 group matches was studied. It is illustrated that rainy conditions suit best to Africans and this is mainly due to two reasons. The first one is cultural and takes into consideration the general approach of African players towards the rain, while the 2nd one may indicate an inability of the rest of the nations to perform well in such conditions, giving African countries the edge. This is enhanced by the fact that in optimal conditions (clear weather) African countries had managed to collect points only in one out of three games of this phase.
On the other hand the trend followed in the total distance covered, as well as the total solo runs during a game, are similar to that of the majority of the countries. In other words, African players manage to cover longer in-game distances and attack effectively the opposition when weather conditions seem more favorable.
Humidity is the amount of vapor water present in the air. It indicates the likelihood of precipitation, dew or fog. Several researches had been conducted in order to find its effect on athletes’ performance, but results are controversial and dependent on the temperature. Zhao, for instance, had pointed out the identical results on aerobic and anaerobic athletics in hot-dry and wet-dry environments.
Below, the interaction between humidity and solo runs could be found. Both the scattering of data and the polynomial fitting are shown to the figure, to provide the reader with an idea of the accuracy of models that have been used. The fitting used is a quadratic one, with b0 at -119.34, b1 around 4.83 and b2 close to -0.0346.
It is clear that with an increase in humidity, African players are fond of declaring direct attacks to ideally score a goal. This enhance in their performance might be attributed to the customary large humidity levels of some specific African countries, like Nigeria or Cote d’Ivoire, and indicates a slight advantage over other nations in such conditions.
For the rest of the depicted correlations only the fitting from regression analysis will be shown.
Cooling breaks were first implemented in the 2014 World Cup due to the relatively high temperatures in Brazil. Temperature plays a critical role to the overall performance of the players and is generally acknowledged as a factor that could change the balance of a match.
African players, being used to high temperatures, perform better when it comes to total scoring opportunities.
On the other hand, despite the fact that they are used in high temperatures, Africans declare direct attacks less often with an increase in ambient temperature (b0 around 60.57 and b1 at -0.7506). However, this trend might be explained by the stagnancy and fatigue of the opponents, driving African teams towards a more cautious, low tempo approach as well.
IV. WIND SPEED
Furthermore, wind speed is considered as the factor with the biggest impact on the style of play for a team. High wind speeds tend to shift the teams towards a more cautious play, with short passes preferred to long balls.
A statistical correlation was observed between the average speed of a player in a variation of several wind speeds, and a parabola was once again introduced to describe this relationship (b0 close to 26.71, b1 at 0.1355 and b2 around -0.0029).
It is concluded that African players are more active when wind speeds are above 5 m/s and they reach at a maximum 23 m/s. This behavior might be attributed to the physical attributes of the African players but it can also show an indication of weather impact on the style of play as mentioned above; High wind speeds make the players run more intensively towards the ball as its movement may be miscalculated by wind alterations. Further investigation should be conducted in order to be able to give a more definite answer.
To wrap up, an effort has been made to explain some out-game characteristics in order to quantify their impact on the performance of African countries. It is clear that even the slightest factor plays a crucial role to this stage of the tournament and managers, along with athletes, need to take everything into consideration.
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Zhao, J., Lorenzo, S., An, N., Feng, W., Lai, L. and Cui, S. (2013). Effects of heat and different humidity levels on aerobic and anaerobic exercise performance in athletes. Journal of Exercise Science & Fitness, 11(1), pp.35-41.
FIFA.com. (2018). 2014 FIFA World Cup Brazil™ – FIFA.com. [online] Available at: https://goo.gl/X7HVBP [Accessed 8 Jun. 2018].