COMPARISON OF TACTICAL BEHAVIOUR EFFICIENCY BETWEEN U-12 AND U-13 YOUTH SOCCER PLAYERS Rodrigo de Miranda Monteiro Santos/NUPEF-UFV Elton Ribeiro Resende/NUPEF-UFV Israel Teoldo da Costa/NUPEF-UFV rodrigo.m.santos@ufv.br KEYWORDS: Soccer; Tactical Behaviour; Age Group. INTRODUCTION The study of team sports through the observation of players behaviour is not recent, having begun alongside with the constraints of expertise (GARGANTA, 2001). In Soccer, as well as in other team sports, tactical behaviour can be defined as the sequences of actions performed by players aiming to deal, by the most appropriate means, with match situations, considering the constraints of time, space and task (BOULOGNE, 1972; GARGANTA, 1997). Accordingly, the analysis of tactical behaviour should not be solely based on a particular action performed in isolation, but rather on general tactical patterns, which comprise all the typical characteristics of isolated actions of all players within a team (MAHLO, 1969). In this respect, tactical behaviour analyses in Soccer have been led in recent years with the purpose of verifying the level in which this variable could be affected by other factors (SAMPAIO; MAÇÃS, 2012). Some researchers examined the association between tactical behaviour and contextual variables (i.e. match location and match status), and concluded that players behaviour can be influenced by these constraints in some degree (TAYLOR et al., 2008; LAGO-PEÑAS, 2009). Yet, there seem to be a lack of further researches over this subject by the perspective of behaviour efficiency, and how it could vary according to different age groups. Thus, this study aims to compare tactical behaviour efficiency between players from U-12 and U-13 age groups. Methods Sample The sample comprised 5,319 tactical actions performed by 100 youth soccer players from U-12 (34 players) and U-13 (66 players) age groups. U-12 players performed 1,873 tactical actions while those from U-13 age group performed 3,446.
Instrument We used the System of Tactical Assessment in Soccer (FUT-SAT) (TEOLDO et al., 2010; TEOLDO et al., 2011), which enables the assessment of tactical actions performed by players with and without ball possession. Such assessment is based on ten core offensive (Penetration, Offensive Coverage, Depth Mobility, Width and Length and Offensive Unity) and defensive (Delay, Defensive Coverage, Balance, Concentration and Defensive Unity) tactical principles of the Soccer game. Procedures This study had the approval of the Ethics Committee from the Federal University of Viçosa (Of. Ref. Nr. 130/2011) and meets the norms established by the National Health Council (466/2012) and by the standards of the Declaration of Helsinki for researches with human beings (1996). In FUT-SAT s field test, participants are grouped in two teams, each one with three players and a goalkeeper (GK+3 vs. 3+GK). Players wore numbered vests of different colours, with the aim of facilitating their identification during video analysis. Players were asked to perform the test respecting the rules of the Soccer game, except by the offside rule (TEOLDO et al., 2011). Tactical behaviour efficiency was assessed through the accuracy of the tactical principles. Material Analyses were performed with the utilization of a laptop computer (DELL Inspiron N4030 Intel Core i3 processor). Video footage was converted into ".avi" files through Prism Video Converter Statistical Analysis Descriptive analysis (frequency, means and standard deviation) was conducted. Kolmogorov-Smirnov test was performed to verify data distribution. For parametric data ANOVA One Way was utilized, while for non-parametric Kruskal-Wallis test was used. Significance level was set to P<0.05. We performed test-retest reliability for the observations, respecting a 20-day interval for reanalysis, thus avoiding task familiarity issues (ROBINSON; O'DONOGHUE, 2007). For reliability calculation we used Cohen s Kappa test. Analyses were verified through the reassessment of 906 tactical actions, or 17.34% of the overall sample, a value which is greater than the percentage (10%) suggested by literature (TABACHNICK; FIDELL, 2012). Intra- and inter-observer reliabilities displayed Kappa values that ranged from 0.814 (SE=0.028) to 0.987 (SE=0.006) and from 0.881 (SE=0.015) to 0.987 (SE=0.005)
respectively. These values are classified as "Almost Perfect" (0.81-1.00) by literature (LANDIS; KOCH, 1977). RESULTS AND DISCUSSION Table 1 presents values of means and standard deviation of the accuracy percentage of tactical principles performed by players from both age groups (U-12 and U- 13). Accuracy Percentage U-12 U-13 sig. OFFENSIVE Penetration 81.48±25.35 81.38±26.71 0.833 Offensive Coverage 92.93±10.62 93.45±10.05 0.831 Depth Mobility 94.59±18.80 80.39±34.69 0.065 Width and Length 92.45±11.01 90.48±12.44 0.317 Offensive Unity 84.37±25.99 85.62±23.91 0.883 DEFENSIVE Delay 78.73±18.45 62.58±27.97 0.005* Defensive Coverage 94.92±17.41 83.37±30.30 0.038* Balance 69.32±25.16 71.81±28.61 0.449 Concentration 95.06±13.78 92.29±15.31 0.192 Defensive Unity 88.17±14.78 83.81±19.08 0.323 Table 1: Means and standard deviation of accuracy percentage of tactical principles Results displayed significant higher values of accuracy percentage of the defensive principles of Delay (P=0.005) and Defensive Coverage (P=0.038) from U-12 compared to U-13 age group. This means that U-13 players were significantly less efficient when performing these principles than U-12 players. Such principles are related to space management inside the game centre (or closer to the ball), what may suggest that players from the U-12 age group were better at performing defensive actions closer to the game centre probably because players from lower age groups are slower in executing actions when in possession (WORTHINGTON, 1974; VÄNTTINEN; BLOMQVIST; HÄKKINEN, 2010). Thus, such limitation might have benefited players who were closer to the game centre, enabling them to easier recover the ball due to the increased time for decision-making (BECHARA, 2004; VÍLLORA et al., 2011). CONCLUSION It is concluded that tactical behaviour efficiency varies according to age group. Future studies should compare tactical behaviour efficiency between age groups where technical skills are expected to be fully developed. ACKNOWLEDGMENTS This study was funded by the State Department of Sport and Youth of Minas Gerais (SEEJ-MG) through the State Act of Incentive to Sports from CAPES, the Dean's Office for
Graduate and Research Studies and the Centre of Life and Health Sciences from the Federal University of Viçosa, Brazil. REFERENCES BECHARA, A. The role of emotion in decision-making: Evidence from neurological patients with orbitofrontal damage. Brain and Cognition, v.55, n.1, p.30-40. 2004. BOULOGNE, G. Organization de jeu - tactique/plan de jeu. E.P.S., v.117, p.52-55. 1972. GARGANTA, J. Modelação táctica do jogo de futebol - estudo da organização da fase ofensiva em equipas de alto rendimento. 1997. 312 p. (Tese de Doutorado). Faculdade de Desporto, Universidade do Porto, Porto, Portugal, 1997. 312 p.. A análise da performance nos jogos desportivos. Revisão acerca da análise do jogo. Revista Portuguesa de Ciências do Desporto, v.1, n.1, p.57-64. 2001. LAGO-PEÑAS, C. The influence of match location, quality of opposition, and match status on possession strategies in professional association football. Journal of Sports Sciences, v.27, n.13, p.1463-1469. 2009. LANDIS, R.; KOCH, G. G. The Measurement of Observer Agreement for Categorical Data. Biometrics, v.33, n.1, p.159-174. 1977. MAHLO, F. L'acte tactique en jeu. Paris: Vigot Freres. 1969. 244 p. ROBINSON, G.; O'DONOGHUE, P. A weighted kappa statistic for reliability testing in performance analysis of sport. International Journal of Perfomance Analysis in Sport, v.7, n.1, p.12-19. 2007. SAMPAIO, J.; MAÇÃS, V. Measuring Tactical Behaviour in Football. International Journal of Sports Medicine, v.33, n.5, p.395-401. 2012. TABACHNICK, B.; FIDELL, L. Using Multivariate Statistics: International Edition. London: Pearson Education. 2012. 1024 p. TAYLOR, J. B.; MELLALIEU, S. D.; JAMES, N.; SHEARER, D. A. The influence of match location, quality of oposition and match status on technical performance in professional association football. Journal of Sports Sciences, v.26, n.9, p.885-895. 2008. TEOLDO, I.; GARGANTA, J.; GRECO, P.; MESQUITA, I.; MAIA, J. Sistema de avaliação táctica no Futebol (FUT-SAT): Desenvolvimento e validação preliminar. Motricidade, v.7, n.1, p.69-84. 2011. TEOLDO, I.; GARGANTA, J.; GRECO, P. J.; MESQUITA, I.; SEABRA, A. Influence of Relative Age Effects and Quality of Tactical Behaviour in the Performance of Youth Soccer Players. International Journal of Perfomance Analysis in Sport, v.10, n.2, p.82-97. 2010.
VÄNTTINEN, T.; BLOMQVIST, M.; HÄKKINEN, K. Development of body composition, hormone profile, physical fitness, general perceptual motor skills, soccer skills and on-theball performance in soccerspecific laboratory test among adolescent soccer players. Journal of Sports Science and Medicine, v.9, n.4, p.547-556. 2010. VÍLLORA, S. G.; LÓPEZ, L. M. G.; VICEDO, J. C. P.; JORDÁN, O. R. C. Conocimiento táctico y toma de decisiones en jóvenes jugadores de fútbol (10 años). Revista de Psicología del Deporte, v.20, n.1, p.79-97. 2011. WORTHINGTON, E. Learning & Teaching Soccer Skills. North Hollywood: Wilshire Book Company. 1974. 182 p.