Research in soccer has traditionally focused on very specific aspects of the game, such as technical and physiological aspects, and has largely ignored important issues such as tactical performance and the role of individual players within the team. The aim of this study was to study the different relationships that Xabi Alonso, one of the world's best midfielders, establishes with his teammates during offensive play, and to investigate his connections with the pitch in terms of where his direct interventions started and finished, his use of technical actions, his involvement in set plays and interceptions, and his relationship with shots at goal. To do this, we analyzed all the matches played by the winner of the 2012 UEFA European Championship: Spain. We employed an observational methodology design (Anguera, 1979) using a modified version of the ad hoc soccer observation instrument designed by Amatria et al. (2016). The resulting data were analyzed by polar coordinate analysis (Gorospe and Anguera, 2000), which is a powerful data reduction technique with high predictive power. The results showed significant associations (Z > 1.96; p < 0.05) between Alonso and players in different positions, a wide sphere of influence on the pitch, both for the start and end of interventions, and a strong link with game interruptions and interceptions and with the use of different technical actions. No significant associations were detected for type of shot. Studies on tactical performance that take account of the multiple factors involved in soccer will lead to better decision-making by coaches and facilitate analysis of a player's true performance.

The objective of the study was to analyze how parental support relates to the physical activity practice, satisfaction with sports, level of physical activity, academic performance and alcohol consumption. Descriptive cross-sectional study, with 1100 adolescents (12–16 years old), where the factors related to parental support, gender and age acted as independent variables, and satisfaction with sport, level of physical activity (PA), academic performance and alcohol consumption acted as dependent variables. A multivariate statistical analysis was conducted. Adolescents with little parental support show (p < 0.001) more boredom, less fun, worse academic performance and higher alcohol consumption. Gender shows differences (p < 0.001) experiencing girls more boredom, less fun, less PA practice and higher academic performance than boys. Age establishes (p < 0.01) that older adolescents (15–16 years old) experience more boredom, less fun, less PA practice, lower academic performance and higher alcohol consumption than young boys and girls (12–14 years old). Parental support towards PA practice improves healthy habits, benefits academic performance and school satisfaction with physical and sports activity.

The use of multidimensional statistical technique based on decision trees is of recent application in sports science. In the case of football, this technique has not yet been sufficiently proven. The aim of the present study was to search for different success models for the corners in the FIFA World Cup 2014 and FIFA Women's World Cup 2015. For this, the statistical analysis focused on the search for classification models for the different criteria considered (shot, shot between the three posts and goal), based on the creation of different decision trees that allow the most important variables to be identified quickly and efficiently. For this, 1117 corners were collected between the two competitions, performed in 116 international matches. It has been possible to establish multivariate models for the "shot" and "shot between the three posts" criteria, allowing, in some cases, to quadruple the potential for offensive success. On the other hand, we have been able to identify significant differences in the male and female model of execution. These findings suggest the need to continue deepening the study of tactical behavior in women's soccer from a multivariate perspective, and also propose a better optimization of the management and training of this type of actions for both male and female football. In addition, it has allowed to test the decision tree statistical technique in the analysis of high performance football, with satisfactory results and of great relevance in the applied field.

The objective of this study was to examine the effect of the situational match status variable on the ball possession of the teams that participated in the 2015 FIFA Women’s World Cup. The 52 games played during the championship have been collected, and 3,740 ball possessions made by the teams were analyzed. The teams have been divided into successful and unsuccessful. Three types of analysis have been carried out: a univariate analysis for both groups with the categorical and continuous variables selected; a bivariate analysis, using chi-square tests and the exact Fischer test; and finally, a multivariable technique such as the decision trees was incorporated. The available results show significant differences between the two groups considered. Specifically, there are significant differences between winning and losing teams in terms of match status. The results of the post hoc test have shown that unsuccessful teams make few ball possessions with a winning match status, most of the possessions are performed when they are losing. Instead, successful teams make more possessions when they are winning than when they are losing. Also, spend more time keeping the ball in their offensive zone, and completing a greater number of passes in it. The results of the decision tree identified that the unsuccessful teams have more ball possessions in forward and middle lines with a draw during the first half, while in the second, a large percentage of possessions are made with an unfavorable match status. Instead, the successful teams have more ball possessions in the first part with a draw, while in the second it happens with a favorable match status.

The aim of this study was to determine the efficacy of defensive play in elite football, to identify variables associated with the direct recovery of ball possession, and to propose a model for predicting the success of defensive transitions. We analyzed 804 transitions in the final stages of the Fedération Internationale Football Association (FIFA) World Cup 2010, and investigated the following variables using univariate, bivariate, and multivariate analyses: duration of defensive transition, possession loss zone, position of players at the start and end of the defensive transitions, defensive organization, general defensive approach, time of the match, position of defense, zone in which the offensive transition ends, match status, and outcome of the defensive transition. We found that the defensive transitions started most frequently in the middle offensive zone (48.9%), with an organized defense set-up (98.8%), and were unsuccessful on 57.2% of occasions. The bivariate analysis showed that the variable most strongly associated with direct recovery of the possession of the ball (p = 0.018) is the area in which the ball is lost, and the multivariate analysis showed that the duration of the defensive transition can be used as a performance indicator, with transitions lasting between 0 and 15 s associated with a higher likelihood of directly recovering the ball. This work has allowed us to identify a pattern of tactical-strategic behavior with major probabilities of success in the defensive transitions. These results will be able to be used by coaches to improve the performance of their teams in this type of situation in the game.

The evolution of soccer over the past 30 years has brought about a faster pace of play and more demanding player dynamics that have led to a paradigm shift in how the game is analyzed. Classic, purely descriptive studies of midfielder performance paint a disjointed picture that is far from the reality of the complex network of relationships and interactions that mark modern-day soccer. The aim of this study was to investigate the relationships established by Xavier “Xavi” Hernández, captain of FC Barcelona and a member of the Spanish national team for many years, during his participation in the final stages of the 2012 UEFA European Football Championship. The authors studied Xavi’s relationship with other players on the pitch, the areas in which his interventions started and ended, his use of technical–tactical skills, and his involvement in set plays. A modified version of a purpose-designed observation instrument was used within an observational methodology study. The data were analyzed by polar coordinate analysis, which is a powerful data reduction technique that reveals significant prospective and retrospective relationships between a focal behavior (Xavi) and other behaviors of interest. The results show that Xavi presents a mutual activation with behaviors from J6 (Iniesta) and J21 (Silva) and significant relationships in attack set-up zones. He is also the most important player in set piece situations, when he uses technical behaviors of control and passing. Studies on tactical performance should analyze all inputs of play and focus on a deep, layered analysis of results to facilitate the work of soccer coaches and educators.