NETWORK THEORY CAN BE APPLIED IN TECHNICAL DECISION MAKING
Applying network theory to football is simply one more method to obtain additional information about a football match.
In elite football, very few goals are scored. Between 70 and 75% of the matches end up with less than 3 goals. For example, in the Premier league, 11.6% of the matches played between the 2000/01 and 2010/11 season finished with a 1-1 score, while the remaining results of 1-1, 2-1, 2-0, and 0-1 were repeated in 10.9%, 9.4%, 8.7%, and 7.6% respectively.1
But not all goals have the same effect on the final score. Scoring or conceding the first goal in the match often leads to important changes in the way many teams play.
A recent research 1 has studied how scoring first influences on the match outcome and how this effect depends on the rival’s level and the minute in which the goal is scored. The study published in the magazine International Journal of Performance Analysis in Sport in 2016, was based on the analysis of all the matches played during the 2014/15 season in the English Premier League (n=380), the Italian Ligue 1 (n=380), the Spanish La Liga (n=380), the Italian Serie A (n=380), and the German Bundesliga (n=306). The results show that if home teams score first, they finally win 84.85% of the matches. On the other hand, if the visitor scores first, 76.25% of them finally win the match. This effect on the final result is quite similar in the five leagues analyzed. Values vary for home teams from 87% in La Liga to 82% in the Serie A, and for visitors from 78% in the Premier League to 75% in the Bundesliga. However, the result of scoring the first goal on the final outcome is influenced by two additional variables: the rival’s level and the moment in which the goal is scored. When home teams play against rivals whose performance are better, similar or worse than theirs, the percentage of matches won after scoring first is 61%, 86% and 70% respectively. When visitors score first and play against a rival whose performance is better, similar or worse than theirs, the percentage of matches won is 57%, 50% and 76%. Goals do not have the same value in all matches.
Finally, the impact of scoring the first goal when nearer to the end of the game is also key: visitors have twice the odds of winning when scoring between the minutes 75-90 than when scoring between the minutes 0-15.
From this analysis, coaches should control the effect of scoring or conceding a goal in the further development of the match and work with the players in these two situations. When the goal is conceded, it is about helping footballers to control their frustration when things didn’t work out as planned. They must be able to stick to the plan devised for the match or modify it and adjust it to the new scenario without losing confidence in what they are doing. If they score first, they will then have to insist on keeping the same performance that has led them to this partial success during the match. Teams must have strategies prepared in order to face both scenarios. Psychological goals do not exist in football, there are no goals that affect more than others. It depends on how players react to the changes in the scoreboard. Whether they are affected for good or bad, that’s the purpose of training: helping to control scenarios during the match that cannot be anticipated.
Carlos Lago Peñas
1 Anderson, C. and Sally, D. (2013). The numbers game. New York: Penguin Books.
2 Lago-Peñas, C.; Gómez-Ruano, M.A.; Megías-Navarro, D. and Pollard, R. (2016). Home advantage in football: Examining the effect of scoring first on match outcome in the five major European leagues. International Journal of Performance Analysis in Sport. 16: 411-421.
Although there are several studies on this topic, many of them have analyzed these demands by looking at just a few variables or using very broad timeframes. A new study completed by physical trainers from F.C. Barcelona has analyzed several of these details more closely.
The understanding of the modifying variables of the game, based on the degrees of freedom.
Sports Analytics has grown exponentially thanks to IT sciences and it also encompasses other subareas (e.g. sports sciences, behavior sciences, medicine or data visualization) in addition to statistics with a focus that is more tactical and sports performance related.