Study of playing styles in the spanish first division of football before, during and after covid-19

Abstract

Due to the worldwide negative impact on sports caused by the COVID-19. The aim was to analyze the influence of the pandemic on playing styles, measured through the interaction of game indicators, to verify the existence of the home advantage effect at three different time points in the Spanish top professional league. To achieve this, 5320 cases (2660 matches) from the 2014/2015 season to 2020/2021of LaLiga were analyzed. All seasons unfolded normally except for the 2019/2020 season, which experienced a three-month hiatus of inactivity due to the pandemic. During the 2020/2021 season, matches began without spectators or with a limited number of fans to maintain the allowed social distance. A descriptive analysis and classification trees using the CRT technique were performed to identify playing styles. The results showed a simplification of the game throughout the seasons. Visiting teams adapted better to more effective playing styles to achieve better results. These differences may be attributed to rule changes, the total/partial absence of spectators, a three-month inactivity period, and the accumulation of matches in a short period of time. Teams should take into account the different situations analyzed in order to display an effective playing style to achieve their different objectives. Keywords: Notational Analysis; Playing style; Classification tree; Performance indicators.