Resumen de Physical, technical and tactical performance analysis of the chinese football super league
Soccer is one of the most extensively analyzed sports, which requires from team and player the high quality of technical, tactical and physical performance, most of the research done on performance analysis in soccer is of an applied nature, based on observational research. Its final objective is to enhance player’s and teams’ performance by providing knowledge which has meaning within the specific context of competition or training. In order to increase the success probability, performance analysis provides the coach and player with information about past performances and may be useful also in generating data for predictive model development. However, there exist still some limitations that need to be considered in the future research, for example: lack of situation and interaction context in which such performances happen; lack of operational definitions and conflicting classifications of activity or playing positions that make it difficult to compare similar group of studies. In order to solve these issues, the following five independent and correlated studies were undertaken in this PhD thesis.
The first study (Chapter 2) aimed to identify the key physical and technical performance variables related to team quality in the 2014 Chinese Super League (CSL). Team’s performance variables were collected from 240 matches and analysed via analysis of variance among end-of-season-ranked groups and multinomial logistic regression. The results indicated significant physical performance differences among groups were identified for sprinting (top-ranked group vs. upper-middle-ranked group) and total distance covered without possession (upper and upper-middle-ranked groups and lower-ranked group). For technical performances, teams in the top-ranked group exhibited a significantly greater amount of possession in opponent’s half, number of entry passes in the final 1/3 of the field and the Penalty Area, and 50-50 challenges than lower-ranked teams. Finally, time of possession increased the probability of a win compared with a draw.
The second study (Chapter 3) aimed to identify and measure different styles of play in professional soccer. The sample comprises all of 240 matches played in the CSL during the 2016 season. Data were examined using a factor analysis. Five factors had eigenvalues greater than 1 and explained 76.1% of the total variance. The following styles of play were found: Factor 1 (“possession" style of play, correlated with the ball possession, ball possession in opponent half and in the final third of the field, positional attacks, passes, accurate passes, passes forward and back), Factor 2 (set pieces attack, correlated positively with the number of set pieces attacks, and negatively with ball possession in own-half), Factor 3 (counterattacking play, correlated with interceptions, interceptions in opponents half, recovered balls, and number of counterattacks) and Factor 4 and 5 (transitional play, correlated with lost balls, and picking up free balls). The results showed that possession style of play were more used by teams Guangzhou Evergrande and Guangzhou RF (best classified teams), and less used by Henan Jianye team (low level team). In addition, the set piece style of play was mainly used by the team Henan Jianye, and less used by Yanbian team.
The third study (Chapter 4) aimed to identify the technical and physical differences between domestic (Chinese) and foreign (no-Chinese) soccer players according to playing-positions in the 2014 CSL; and to classify domestic and foreign players (best/worst) based on their match performance characteristics. Data were provided by Amisco Sports Analysis Services, a total of 3,468 observations were examined in the study. Discriminant and one-way ANOVA analyses showed important differences between domestic and foreign players in the CSL in terms of physical and technical performance indicators for various playing positions. More specifically, foreign players performed more passes, shots, and aerial and ground challenges when compared with domestic players. While fewer physical performance differences were observed between groups, foreign WD and WM covered greater distances than their counterparts, and domestic F covered greater distances than their foreign counterparts. Additionally, the best foreign players exhibited greater values for most variables per playing position (e.g. CD, WD, CM, WM and F) compared to the worst foreign and best/worst domestic players. Lastly, the best domestic players were better than the worst foreign players for total distance (CD, WD, WM and F), high-intensity (WM), number of high-intensity actions (WM), sprint (WM), number of sprint (WM), sprint of total distance (WM), number of passes (CM and WM), number of forward passes (CM), number of ground challenges (CD), and number of shots and shot success (F).
The fourth study (Chapter 5) aimed to compare the technical and physical performances of starters, substitutes and whole-match players of different playing positions: central defender, full-back, central mid-fielder, wide mid-fielder, and forward. Data were collected from 240 matches of the Chinese Super League (CSL) that involved 16 teams during the 2014 season. Match performance data were gathered by Amisco Sports Analysis Services and Opta Sportdata and analyzed using independent or paired t-tests of the following groups: starters (n=4,794) vs. substitutes (n=1,208); whole-match players (n=3,505) vs. substitutes (n=1,208); within-player comparisons, starters (n=258) vs. substitutes (n=258). Between-player and within-player analyses, demonstrated that substitutes experienced greater work-rates (e.g. high-intensity runs) and completed more technical actions (e.g. pass success) than starters but with a lower efficacy. These findings not only provide the information to coaches for optimizing the impact of player’s performance on match play and also provide support in the development of substitution strategies to manage team success during competition.
The final study (Chapter 6) aimed to identify the key performance indicators related to technical and tactical aspects by playing position (defender, midfielder and forward) and nationality in the Chinese Football Super League (CSL). Data were collected from 240 matches of CSL played by 16 teams in the 2016 season. Match performance data were gathered by OPTA Sports Data from a total of 2,364 observations that included domestic (n=1,081) and foreign players (n=1,283) observations. All comparisons were completed by the nonclinical magnitude-based inferences. The analyses of 49 variables related to passing and attack organization, defense and goal scoring showed significant differences between domestic and foreign players when analyzed according to playing positions. Therefore, the current study provides match performance profiles that can be used by coaches to improve the recruitment process and team composition with regard to domestic and foreign players.
This PhD thesis has brought some novel aspects of match performance of team and player in the elite adult male soccer competitions. Additionally, this PhD thesis has established team and player’s performance profiles, which can be used in team’s management, player’s performance assessment, recruitment process, and also provide coaching staffs with important information related to physical, technical and tactical differences for the proper practice in the CSL.
