Loading...
17 results
Search Results
Now showing 1 - 10 of 17
- Who are the prominent players in the UEFA champions league? : an approach based on network analysisPublication . Manuel Clemente, Filipe; M. L. Martins, FernandoThis study aimed to analyze the centrality levels of elite football players. Tactical positions and tactical line-ups were considered factors to be used in analyzing the variance in the prominence of players, measured by social network measures. The best 16 teams from the UEFA Champions league were analyzed during the entire competition. A total of 109 matches were analyzed for this study. Significant statistical differences between positions were found in % indegree (p = 0.001; ES = 0.268, moderate effect), % outdegree (p = 0.001; ES = 0.301, moderate effect) and % betweenness (p = 0.001; ES = 0.114, minimum effect). No statistical differences between tactical line-ups in % outdegree (p = 1.000; ES = 0.001, no effect) or % indegree (p = 1.000; ES = 0.001, no effect) were found. Central midfielders had the greatest values of centrality, thus confirming their importance in the linkage process of the team. Position had great influence on the centrality levels of players.
- Network analysis in basketball : inspecting the prominent players using centrality metricsPublication . Manuel Clemente, Filipe; M. L. Martins, Fernando; Kalamaras, Dimitris; Mendes, RuiThe aim of this study was to analyse the team-members cooperation in basketball by using centrality metrics of network. Different ages were compared in this study. Forty players (10 players of under-14; 10 players of under16; 10 players of under-18 and 10 players in amateurs with more than 20 years) voluntarily participated in this study. A total of 326 units of attack were generated based on the team-members interactions and then converted in final graphs. The one-way ANOVA for the factor tactical position found statistical differences in the dependent variables of %DCentrality (F(4,15) = 13.622; p-value = 0.001; n2 = 0.784; Large Effect Size) and %DPrestige (F(4,15) = 20.590; p-value = 0.001; n2 = 0.846; Large Effect Size). In conclusion this study showed that point guard was the prominent position during the attacking organization and that social network analysis it is a useful approach to identify the patterns of interactions in the game of basketball.
- Measuring collective behaviour in football teams : inspecting the impact of each half of the match on ball possessionPublication . Manuel Clemente, Filipe; Couceiro, Micael; M. L. Martins, Fernando; Mendes, Rui; Figueiredo, AntónioThe aim of this study was to inspect the influence of each half of matcha and the ball possession status on the players’ spatio-temporal relationships. Three official matches of a professional football team were analysed. From the players' locations were collected the team’s wcentroid, wstretch index, surface area and effective area of play at 9218 play instants. The results suggested that the values of teams’ dispersion and average position on the field decreases during the 2nd half of the match. In sum, this study showed that the half of match and the ball possession status influenced players’ spatio-temporal relationships, in a way that significantly contributes to the collective understanding of football teams.
- Physical and technical performances are not associated with tactical prominence in U14 soccer matchesPublication . Manuel Clemente, Filipe; Figueiredo, António José; M. L. Martins, Fernando; Mendes, Rui; Wong, Del P.The aim of this study was to analyse the association between physical/technical variables and the tactical prominence variables in U14 soccer matches. Twenty-two young amateur soccer players (13.5 0.5 years old, 5.4 0.5 years of practice, 163.3 9.8 cm in body height) from two teams of the Portuguese regional league volunteered for the study. Our results showed positive and moderate correlation between dribbling test and betweenness centrality (r = 0.324; p = 0.142), and negative moderate correlation between %fatigue index and betweenness centrality (r = −0.390; p = 0.073). Physical and technical variables had no statistical differences among tactical positions. Nevertheless, when tactical prominence of players from four tactical positions were compared, significant differences were found in terms of degree prestige (p = 0.001) and degree centrality (p = 0.002). This pilot study did not find strong correlations between physical/technical levels and tactical prominence in soccer matches.
- Social network measures to match analysis in soccer : a surveyPublication . Manuel Clemente, Filipe; M. L. Martins, Fernando; Mendes, Rui; G. M. Silva, FrutuosoIn this study we will present the most common and adequate network measures to analyse graph properties and to inspect the prominence of each player on a soccer team. Both approaches can provide a range of useful information. This kind of analysis will help to identify the prominence of players and also characterize the collective organization and patterns of the teams. General measures and centrality levels will be described and the applications will be discussed. By using social network analysis will be possible to quantify the structure of play and predict some behaviour. Such methodology will add new options to the field of match analysis.
- Using network metrics to investigate football team players’ connections : a pilot studyPublication . Manuel Clemente, Filipe; Couceiro, Micael; M. L. Martins, Fernando; Mendes, RuiThe aim of this pilot study was propose a set of network methods to measure the specific properties of football teams. These metrics were organized on “meso” and “micro” analysis levels. Five official matches of the same team on the First Portuguese Football League were analyzed. An overall of 577 offensive plays were analyzed from the five matches. From the adjacency matrices developed per each offensive play it were computed the scaled connectivity, the clustering coefficient and the centroid significance and centroid conformity. Results showed that the highest values of scaled connectivity were found in lateral defenders and central and midfielder players and the lowest values were found in the striker and goalkeeper. The highest values of clustering coefficient were generally found in midfielders and forwards. In addition, the centroid results showed that lateral and central defenders tend to be the centroid players in the attacking process. In sum, this study showed that network metrics can be a powerful tool to help coaches to understanding the specific team’s properties, thus supporting decision-making and improving sports training based on match analysis.
- Effects of the sports level, format of the game and task condition on heart rate responses, technical and tactical performance of youth basketball playersPublication . Manuel Clemente, Filipe; González-Víllora, Sixto; Delextrat, Anne; M. L. Martins, Fernando; Vicedo, Juan Carlos PastorThe aim of this study was to analyze the effect of different small-sided and conditioning games (SSCG) with different tactical contents on heart rate responses, technical performance and collective organization of youth basketball players of different performance levels. Twenty male basketball players from U14 (13.7 ± 0.8 years old; 4.2 ± 1.4 years of practice) and U16 (15.3 ± 1.1 years old; 6.4 ± 2.1 years of practice) participated in this research study. The two-way MANOVA revealed that the sports level (p = 0.009; = 0.151), format (p = 0.001; = 0.246) and task condition (p = 0.023; = 0.104; small effect size) had significant main effects on heart rate responses. It was also found that the format (p = 0.001; = 0.182) had significant main effects on technical performance. A smaller format significantly increased the heart rate, volume of play, efficiency index and collective density during attacking plays. The SSCG with attacking content statistically increased the heart rate, efficiency index and performance score. Therefore, this study revealed that different SSCGs with tactical content influenced the physiological responses of youth players.
- Analysis of physiological, technical, and tactical analysis during a friendly football match of elite U19Publication . Ortega, Juan Ignacio; Evangelio, Carlos; Manuel Clemente, Filipe; M. L. Martins, Fernando; González-Víllora, SixtoThe main objective was to analyze a friendly match of youth elite soccer players identifying the variance of tactical and physiological response parameters during the game. In addition, detecting the impact of both halves on player performance. For the purposes of this study twenty-two U19 players were analyzed playing 11v11. Activity profile, heart rate (HR and HRmax), grouped in five different zones were analyzed via Bluetooth technology, technical performance was analyzed by the Team Sport Assessment Procedure (TSAP), and tactical performance was measured by Social Network Analysis. A comparison of heart rate responses showed significant main effects in the halves (p = 0.001; η 2 p = 0.623). A comparison between tactical position and technical performance had significant main effects (p = 0.001; η 2 p = 0.390). Tactical position showed statistically significant effects on tactical prominence (p = 0.002; η 2 p = 0.296). Therefore, fatigue is a component distinguished in technical/tactical parameters, such as volume of play and efficiency index. Results suggest that fatigue effects may constrain technical performance and, for that reason, the use of instruments to monitor the fatigue effect during matches may be suggested.
- There are differences between centrality levels of volleyball players in different competitive levels?Publication . Manuel Clemente, Filipe; M. L. Martins, Fernando; Mendes, RuiThe aim of this study was to analyse the variance of network centrality levels between different competitive levels and tactical positions during attacking moments. Twenty-four volleyball players (U12 – 12 players, 11.7 0.4 years old, 1.9 0.9 years of practice; Amateurs – 12 players, 24.9 4.2 years old, 12.6 2.8 years of practice) voluntarily participated in this study. The multivariate MANOVA revealed no statistical differences in the independent variable of competitive level (λ = 0.001; F(3,22) = 0.001; p-value = 1.000; = 0.001; Very Small Effect Size). Statistical differences were found in the independent variables of tactical position (λ = 1.015; F(15,72) = 2.454; p-value = 0.006; = 0.338; Moderate Effect Size). The post hoc values revealed that position 3 is the prominent player during attacking moments in both competitive levels and that position 5 reveals the smallest centrality levels in attack.
- Technical accuracy it is associated with prominence levels in basketball?Publication . Manuel Clemente, Filipe; M. L. Martins, Fernando; Mendes, RuiThe aim of this study it was verify the association level between technical accuracy and tactical prominence variables of basketball players from different competitive levels. For such analysis, technical accuracy it was analysed using Team Sports Assessment Procedure and tactical prominence using social network analysis metrics. Forty-two basketball players from four different competitive levels (U14, U16, U18 and amateurs with more than 20 years old) it were observed during three official matches. Correlation tests revealed that %inDegree showed a large positive correlation with efficiency index (r = 0.665; p = 0.001) and very large positive correlation with volume of play (r = 0.844; p = 0.001) and performance score (r = 0.843; p = 0.001). The %outDegree showed very large positive correlation with volume of play (r = 0.743; p = 0.001), efficiency index (r = 0.710; p = 0.001) and performance score (r = 0.776; p = 0.001). This study allowed to identify that technical accuracy has great levels of correlation with tactical prominence, mainly in the case of inDegree centrality.