ARTICLE | doi:10.20944/preprints202208.0437.v1
Subject: Medicine & Pharmacology, Other Keywords: COVID-19; LaLiga; sports; spatial and temporal analysis; serological status
Online: 26 August 2022 (02:59:56 CEST)
Objectives: COVID-19 pandemic interrupted the Spanish professional football competition until May 2020, when it was restarted following a surveillance protocol established by LaLiga. The aims were to describe the infective and serological status of professional football players (PLY) and staff (STF) between May 5th 2020 until April 22nd 2021, to analyze the spatial-temporal distribution of the COVID-19 disease in this cohort and its comparison to the Spanish population. Methods: a prospective observational cohort study was carried out. Differences between PLY and STF were assessed by Chi-squared test and test of equality of proportions. Pearson correlation test was used to measure the presence of an association between the percentages of positivity in population and LaLiga cohort. Results: 137,420 RT-PCR and 20,376 IgG serology tests were performed in 7,112 professionals. Positive baseline serology was detected in 10.57% of PLY and 6.38% of STF. Among those who started the follow-up as not infected and before STF vaccination, 11.87% of PLY and 5.03% of STF became positive. Before summer 2020 the prevalence of infection was similar than the observed at national level. The percentage of positivity in the Spanish population was higher than in LaLiga cohort, but both series showed a similar decreasing trend.
Subject: Social Sciences, Accounting Keywords: performance analysis; elite football; multivariate analysis; principal components analysis; LaLiga
Online: 8 February 2021 (16:18:14 CET)
The use of principal components analysis provided information about the main characteristics of teams, based on a set of indicators, instead of displaying individualized information for each of these indicators. In this work we have considered reducing an extensive data matrix to improve interpretation, using the principal components analysis. Subsequently, with new components and with a multiple linear regression, we have carried out a comparative analysis between the best and bottom teams of LaLiga. The sample consisted of the matches corresponding to the 2015/16, 2016/17 and 2017/18 seasons. The results showed that the best teams were characterized and differentiated from bottom teams in the realization of a greater number of successful passes and in the execution of a greater number of dynamic offensive transitions. The bottom teams were characterized by executing more defensive than offensive actions and showing a fewer number of goals, a greater ball possession time in the final third of the field. Goals, ball possession time in the final third of the field, number of effective shots and crosses are the main performance factors that influence the offensive success of football. This information allows us to increase knowledge about the key performance indicators in football.
ARTICLE | doi:10.20944/preprints201907.0072.v1
Subject: Social Sciences, Other Keywords: performance analysis; football; gender differences; LaLiga; technical-tactical behaviour; observational methodology
Online: 4 July 2019 (09:38:22 CEST)
The aim of this study was to identify gender differences in technical-tactical behaviour in football. To this end 68 matches of the first division of the Spanish men’s and women´s league, corresponding to 2016/17 season were analyzed. A comparison of medians was carried out using the Mann-Whitney U-test were conducted as post hoc test and a grouping of the variables through the clustering bootstrapping technique in both groups. We have detected statistically significant differences regarding all accurate passes, in favour of men, as well as a greater number of yellow cards. In female football, a greater number of picking up free balls, interceptions, lost balls, recoveries, challenges and attacks, both positional and counterattacks, are produced. The clustering analysis also allowed that in male football, the circumstance of receiving a red card is closely related to the number of goals conceded and most of the shots on goal are achieved by positional attacks. In women's football, ball possession on own half is closely related to the number of losses. These results could be useful for gender-specific training information for optimal preparation. However, more research is warranted to establish the main gender differences and characterize women's football.