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Concept: UEFA Champions League


The aim of the study was a detailed analysis of the sprinting activity of professional soccer players. The study involved 147 players who played in 10 matches of the 2008-2009 and 2010-2011 UEFA Europa League seasons. The number of performed sprints and total sprint distances covered by the players were examined using collected statistical material. Two types of sprints were distinguished based on their duration: S - short duration sprint (below 5 s) and L - long duration sprint (above 5 s). Additionally, sprints were classified according to their distance: 0-10 m, 10.1-20.0 m, and > 20 m, respectively. The analysis of the sprinting activity of soccer players also involved their respective positions of play. The study was carried out using Amisco Pro® (ver. 1.0.2, Nice, France), one of most comprehensive, up-to-date computer systems for match analysis.The statistical analysis revealed that the mean total sprint distance covered by players (≥ 24 km • h-1) amounted to 237 ± 123 m. With regard to the position of play, the forwards covered the longest sprint distance (345 ± 129 m), i.e. 9% longer than midfielders (313 ± 119 m), and over 100% longer than central midfielders (167 ± 87 m). The average number of sprints performed by the soccer players was 11.2 ± 5.3. It should also be emphasized that about 90% of sprints performed by professional soccer players were shorter than 5 s, while only 10% were longer than 5 s. Analysis of physical loads of soccer players during matches can be useful for individualization of training of soccer players' speed capabilities. It is an essential instrument of modern planning and application of training loads.

Concepts: Statistics, Arithmetic mean, Average, Running, UEFA Europa League, UEFA, UEFA Champions League, UEFA Intertoto Cup


Background: Football (soccer) betting, as a strategic form of betting, became one of the favorite wagers for pathological gamblers. Previous studies demonstrated the psychological and biological significance of the ‘illusion of control’ (personal control) and ‘near miss’ results in gambling. In our study, we explored whether knowledge and expertise of pathological sports gamblers can ensure a successful bet. Sample and Methods: Participants were divided into three groups of individuals - pathological gamblers, amateurs and laypersons - and were asked to predict in advance the general result and the exact result of football matches in the European Champions League Round of 16. Results: The 165 participants included 53 pathological sports gamblers (52 males and 1 female), 78 laypersons (45 females and 33 males) and 34 amateurs (all males). After a thorough statistical analysis, we found no significant differences between the groups, no matter what kind of previous knowledge they had acquired. Conclusion: This study demonstrates that the ‘illusion of control’ of pathological gamblers, attained by knowledge of the game and its latest data and information (especially in a strategic gamble as football betting), has no factual background. Moreover, our study demonstrates without a doubt that there is no significant difference between the male pathological sports gamblers group and the male/female laypersons group.

Concepts: Male, Female, Statistical significance, Sex, Probability, Gambling, UEFA Champions League, Bookmaker


The aim of this study was to define and categorise different styles of play in elite soccer and associated performance indicators by using factor analysis. Furthermore, the observed teams were categorised using all factor scores. Data were collected from 97 matches from the Spanish La Liga and the English Premier League from the seasons 2006-2007 and 2010-2011 using the Amisco® system. A total of 19 performance indicators, 14 describing aspects of attacking play and five describing aspects of defensive play, were included in the factor analysis. Six factors, representing 12 different styles of play (eight attacking and four defensive), had eigenvalues greater than 1 and explained 87.54% of the total variance. Direct and possession styles of play, defined by factor 1, were the most apparent styles. Factor analysis used the performance indicators to cluster each team’s style of play. Findings showed that a team’s style of play was defined by specific performance indicators and, consequently, teams can be classified to create a playing style profile. For practical implications, playing styles profiling can be used to compare different teams and prepare for opponents in competition. Moreover, teams could use specific training drills directed to improve their styles of play.

Concepts: Factor analysis, Premier League, Association football, Team, La Liga, UEFA, UEFA Champions League, Serie A


Epidemiological studies on football (soccer) injuries are needed to assess both the magnitude of the problem and the effectiveness of preventive programmes. However, few data are available for Italy, which hosts one of the main football leagues in Europe. In this study, we aimed to describe the epidemiology of football injuries in the 2012/2013 and 2013/2014 seasons of the Italian Serie A. Information about injury location, type, date of occurrence and duration of absence was obtained from , a free collaborative international database on football. Overall, 363 injuries occurred throughout the two seasons affecting 286 players. The most commonly reported injuries were thigh-strain and knee injury, which accounted for 42% and 19% of all injuries, respectively. Injury incidence increased with age and was particularly higher from August to October. Results suggest that injury prevention strategies should be introduced from the preseason to reduce the risk of injuries, especially muscle strains.

Concepts: Epidemiology, Premier League, Association football, Italy, UEFA Champions League, Serie A


BACKGROUND: The influence of injuries on team performance in football has only been scarcely investigated. AIM: To study the association between injury rates and team performance in the domestic league play, and in European cups, in male professional football. METHODS: 24 football teams from nine European countries were followed prospectively for 11 seasons (2001-2012), including 155 team-seasons. Individual training and match exposure and time-loss injuries were registered. To analyse the effect of injury rates on performance, a Generalised Estimating Equation was used to fit a linear regression on team-level data. Each team’s season injury rate and performance were evaluated using its own preceding season data for comparison in the analyses. RESULTS: 7792 injuries were reported during 1 026 104 exposure hours. The total injury incidence was 7.7 injuries/1000 h, injury burden 130 injury days lost/1000 h and player match availability 86%. Lower injury burden (p=0.011) and higher match availability (p=0.031) were associated with higher final league ranking. Similarly, lower injury incidence (p=0.035), lower injury burden (p<0.001) and higher match availability (p<0.001) were associated with increased points per league match. Finally, lower injury burden (p=0.043) and higher match availability (p=0.048) were associated with an increase in the Union of European Football Association (UEFA) Season Club Coefficient, reflecting success in the UEFA Champions League or Europa League. CONCLUSIONS: Injuries had a significant influence on performance in the league play and in European cups in male professional football. The findings stress the importance of injury prevention to increase a team's chances of success.

Concepts: Association football, UEFA Europa League, UEFA, UEFA Champions League, FIFA, FIFA Club World Cup


We test the soccer myth suggesting that a particularly good moment to score a goal is just before half time. To this end, rich data on 1,179 games played in the UEFA Champions League and UEFA Europa League are analysed. In contrast to the myth, we find that, conditional on the goal difference and other game characteristics at half time, the final goal difference at the advantage of the home team is 0.520 goals lower in case of a goal just before half time by this team. We show that this finding relates to this team’s lower probability of scoring a goal during the second half.

Concepts: Association football, UEFA Europa League, UEFA, UEFA Champions League, UEFA Intertoto Cup, Liverpool F.C.


The Nordic hamstring (NH) exercise programme was introduced in 2001 and has been shown to reduce the risk of acute hamstring injuries in football by at least 50%. Despite this, the rate of hamstring injuries has not decreased over the past decade in male elite football.

Concepts: Premier League, Association football, Accident, La Liga, UEFA, UEFA Champions League, Promotion and relegation, Serie A




Talent identification and development in soccer is often biased by maturation-related differences of young athletes. However, there is no information available about success rates for youth maturing at different tempos to achieve success in elite adult soccer. The purposes of this study were to determine the prevalence of different maturational groups among boys playing soccer, and to track them for competence in adult performance. A prospective cohort study design was used to follow 55, 14-year-old boys playing in Serbian youth soccer Division I over eight years. At the age of 14, biological age using skeletal age rates was determined, and participants were categorized as early maturers (EaM), normal maturers (NoM), and late maturers (LaM). Game competence for adult soccer at age 22 was described as elite if an individual played for clubs competing in top-five international soccer leagues (La Liga, Premier League, Bundesliga, Serie A, and Ligue 1), and/or has become a member of an adult National team. Among boys in our study group, 43.8% were categorized as EaM, 35.4% as NoM, and 20.8% as LaM (P = 0.11). A significant difference in biological age was found among maturational groups at age 14, with EaM > NoM > LaM (P > 0.0001). When assessed for adult soccer competence, 33.3% of participants (16 out of 48 players) succeed in achieving elite level. Elite soccer competence acquired 60.1% players from the group of LaM, 38.1% from NoM, and 11.8% from EaM (P > 0.0001). Our comparative analysis suggests that soccer excludes early maturing boys and favors late maturing boys as level of performance increases.

Concepts: Cohort study, Premier League, Association football, La Liga, UEFA, UEFA Champions League, Ligue 1, Serie A