How to be successful in professional football: analysis of physical demands and match statistics of professional football teams competing in laliga

Abstract

The football performance depends on the combination of in-game technical, physical, and tactical actions in a context in which players’ psychology and motivation are also key for performance. The main objective of this Doctoral Thesis was to investigate the physical demands and game statistics of best-ranked and worse-ranked teams of the professional football first division league in Spain (LaLiga). Furthermore, a second objective was to analyse how the suspension of LaLiga due to the COVID-19 pandemic affected teams’ physical performance. To fulfil these objectives, we conducted 8 studies with descriptive, comparative, and relational experimental designs to analyse match data generated during ten seasons of LaLiga. In Study 1, accumulated teams’ attack and defensive match statistics were analysed along with the points earned at the end of each season in LaLiga for eight seasons (2010–2011 to 2017–2018). The analysis included a total of 3040 football matches. A multiple regression analysis was able to explain 84.1% of the total variance in the number of points earned at the end of the season with attacking statistics. Defensive statistics explained 73.5% of the variance in the end-season points. Overall, shooting accuracy while attacking along with avoiding clear positions for shooting from the opposing team were the indicators best associated with the points obtained at the end of the LaLiga championship. The aim of Study 2 was to analyse in-game match statistics of the top-3 and bottom- 3 teams ranked in LaLiga for eight seasons (2010–2011 to 2017–2018). Accumulated offensive and defensive match statistics when playing at home and away were obtained. The match statistics that best discriminated successfully from unsuccessful football teams were shooting accuracy while attacking and the number of shots conceded while defending. In addition, the game statistics related to passing were not related to success in football. The aim of Study 3 was to identify match statistics that best explained the differences between the first- and the second-placed teams in LaLiga. For this aim, the number of wins draws, losses, distribution of scored/ received goals, and accumulated attack, and defensive match statistics were obtained of the 1st and 2nd place teams for eight seasons (from 2010–2011 to 2017–2018). A higher number of wins when playing away was the best indicator of performance to differentiate between the winner and the second-place team in LaLiga. Increased shooting accuracy and conceding fewer shots from corners might also aid in obtaining victory in LaLiga. The aim of Study 5 was to determine the relationship between match running patterns with and without ball possession and the number of points earned at the end of the LaLiga. Running distance covered with and without ball possession at speeds ≥21 and <21 km/h were analysed for four seasons (2015–2016 to 2018–2019). Best football teams covered a greater distance with the ball than the less successful teams. Afterward, the aim of Study 6 was to determine the influence of a player’s peak/maximum running speed on the team’s ranking position at the end of a national league. Peak/maximum running speeds of 475 male professional football players were recorded for 38 fixtures in LaLiga for the 2017–2018 season. Successful and less successful football teams have squads with players able to obtain similar maximum running speeds during match play throughout the season. Hence, players’ maximum running speeds have a poor association with the team’s ranking position at the end of the LaLiga. Study 7 and Study 8 were associated with the suspension of LaLiga in the 2019-2020 season due to the first wave of the COVID-19 pandemic. This season was suspended for 12 weeks, and it was resumed to finish the remaining 11 fixtures. The aim of Study 7 was to perform a descriptive and comparative analysis of the running performance of teams competing in LaLiga across 4 seasons (2015-2016 to 2018-2019). We carried out this analysis to anticipate teams’ physical performance after the resumption of the competition as the suspension mimicked the duration of the transition period and preseason of prior seasons. The analysis included the average running distance per game for each of the 38 matchdays that compose LaLiga. This analysis revealed that teams habitually need 8-10 matchdays to reach a steady state of running performance. These data suggested that football players would progressively increase their performance across the 11 matchdays that were left to complete LaLiga in the 2019-2020 season. The aim of Study 8, was to analyse running patterns before suspension and after the resumption of LaLiga in the 2019-2020 season to determine how the lockdown affected players’ physical performance. A pairwise comparison was performed of running patterns of 2019–2020 vs. 2018–2019 season (i.e., control season). The analysis indicated that the high-intensity running performance of professional football teams was maintained after the resumption of the competition while the above-mentioned alterations likely aided in the in-game regulations that facilitated the maintenance of physical performance. As main conclusion, success in professional football in LaLiga was associated with shooting accuracy and the ability of teams to prevent the opposing team from shooting from a comfortable position. Interestingly, physical performance variables as running distance with and without the ball, peak running velocity, and the time when a goal is scored are poorly associated with success in LaLiga. In addition, although it was initially speculated that the physical performance of the teams would be notably reduced after home confinement during COVID-19 first wave, the introduction of new regulations allowed the team's physical performance to be maintained in the 11 rounds that were played to conclude the 2019-2020 season.