Júlio Garganta

Shared Knowledge or Shared Affordances? Insights from an Ecological Dynamics Approach to Team Coordination in Sports

Previous research has proposed that team coordination is based on shared knowledge of the performance context, responsible for linking teammates’ mental representations for collective, internalized action solutions. However, this representational approach raises many questions including: how do individual schemata of team members become reformulated together? How much time does it take for this collective cognitive process to occur? How do different cues perceived by different individuals sustain a general shared mental representation? This representational approach is challenged by an ecological dynamics perspective of shared knowledge in team coordination. We argue that the traditional shared knowledge assumption is predicated on ‘knowledge about’ the environment, which can be used to share knowledge and influence intentions of others prior to competition. Rather, during competitive performance, the control of action by perceiving surrounding informational constraints is expressed in ‘knowledge of’ the environment. This crucial distinction emphasizes perception of shared affordances (for others and of others) as the main communication channel between team members during team coordination tasks. From this perspective, the emergence of coordinated behaviours in sports teams is based on the formation of interpersonal synergies between players resulting from collective actions predicated on shared affordances.

Sistema de avaliação táctica no Futebol (FUT-SAT): Desenvolvimento e validação preliminar

The purpose of this paper was to report the development and preliminary validation of tactical assessment system in Soccer and highlight its advantages. The validation process followed five perspectives of the concept of validity that consider the value of heuristic methods and the importance of the description of behavior performed in playing situations. Thus, the process of validation was focused on four points: i) acceptability and reasonableness of the test perceived by players; ii) analysis of content of assessment tool through a panel of experts; iii) potential of the assessment tool to discriminate the quality of the performance of players; iv) observation reliability. The results displayed values higher than 0.63 for correlation between the evaluations of coaches and the system. It shows the potential of this system to distinguish the performances of players based on the evaluations of coaches. The players who performed the field test agreed with its physical demands and spatial and normative configurations. All experts endorsed the categories and variables of this system. The reliabilities showed values higher than 0.79 for intra and inter-observers. Therefore, it is possible to conclude that the system is valid and reliable for the assessment of the tactical behavior of soccer players.

Influence of Relative Age Effects and Quality of Tactical Behaviour in the Performance of Youth Soccer Players

The present study examines the associations between tactical performance indexes with quality of tactical behaviours and birth-date quarters of youth Soccer players. The sample comprised a total of 534 youth players classified into four seasons of 3 months (January-March; April-June; July-September; October-December). A system of tactical assessment in Soccer (FUT-SAT) was used to collect data. Descriptive statistics and multinomial logistic regression were applied. The tactical performance indexes were divided into tercis (low, moderate and high) in order to evaluate the influences of relative age effects and quality of tactical behaviours. The quality in the “penetration” and “offensive coverage” principles were positively related to moderate performance indexes. Players with the highest quality in the “depth mobility” and “unity defensive” principles were more likely to present higher performance indexes. Regarding the defensive phase, those with better qualities in the “delay”, “concentration” and “defensive unity” principles were more likely to have moderate performance index. Additionally, better quality in the “defensive coverage” and “balance” principles corresponded to a higher likelihood of having a superior performance index. Relative age effects were observed only in high defensive performance index. The present results revealed a positive correlation between tactical performance indexes and quality of tactical behaviours.

Ball recovery patterns as a performance indicator in elite soccer

In soccer, it seems relevant to understand the relationship between the ball recovering and the subsequent success or failure of attacking play. However, few studies have considered the links between the type of ball recovery in different pitch zones, the competition stages and the overall teams success. The present study aims to analyze the attacks (n = 1619) carried out by the semi-finalist teams in the 2010 FIFA World Cup in order to explore ball recovery patterns as a performance indicator. SoccerEye observational instrument, SoccerEye recording software, Sequential Data Interchange Standard-Generalized Sequential Querier (SDIS-GSEQ) and SPSS analytic software—one-way analysis of variance, two-way analysis of variance and regressions—were applied. Direct ball recovery, in specific by interception and defensive behavior followed by a pass, was the mostly frequent behavior, with the later inducing attacking play efficacy (p<0.017). Differences were detected between the group and play-off stages with regard to the types of direct ball recoveries. The ball was most often regained in defensive and mid-defensive central zones, evidencing differences to all other pitch zones (p≤0.001). Throw-ins were the only type of ball recovery that differentiated the semi-finalists, namely Germany and Spain (p<0.009). It was found that recovering directly the ball possession in mid-defensive central zones increases attacking efficacy. Consequently, coaches should consider this tactical determinant in order to organize the training process. Specifically, it is fundamental to improve the collective defensive organization protecting central strip zones and simultaneously performing high-pitched pressure to constrain the ball carrier.

Field dimension and skill level constrain team tactical behaviours in small-sided and conditioned games in football.

Abstract This study analysed the influence of field dimension and players’ skill level on collective tactical behaviours during small-sided and conditioned games (SSCGs). Positioning and displacement data were collected using global positioning systems (15 Hz) during SSCGs (Gk+4 v. 4+Gk) played by two groups of participants (NLP- national-level and RLP-regional-level players) on different field dimensions (small: 36.8 × 23.8 m; intermediate: 47.3 × 30.6 and large: 57.8 × 37.4 m). Team tactical performance was assessed through established dynamic team variables (effective playing space, playing length per width ratio and team separateness) and nonlinear signal processing techniques (sample entropy of distances to nearest opponents and the teams’ centroids’ mutual information). Results showed that the effective playing space and team separateness increased significantly with pitch size regardless of participant skill level (P < 0.001, η2 = 0.78 and P < 0.001, η2 = 0.65, respectively). Playing length per width ratio increased with pitch size for the NLP but was maintained at a relatively constant level by RLP across treatments indicating different playing shapes. There was significantly more irregularity in distances to nearest opponents for the NLP in small (P = 0.003) and intermediate fields (P = 0.01). Findings suggest that tactical behaviours in SSCGs are constrained by field size and skill level, which need to be considered by coaches when designing training practices.

Abordagem sistêmica do jogo de futebol: moda ou necessidade?

Varias tentativas tem sido feitas para descrever a estrutura do rendimento no Futebol. No entanto, apesar de alguns factores poderem ja ser reunidos, os catalogos de prioridades e as estruturas hierarquicas estabelecidas pouco mais tem conseguido do que reproduzir pequenas e desarticuladas fraccoes do jogo. Todavia, a realidade tem demonstrado que a pertinencia do estudo dos problemas inerentes ao jogo e ao jogador devera situar-se mais ao nivel da interaccao dos factores do que em cada um deles per se. Diversas conclusoes decorrentes de varios estudos realizados, fazem emergir a necessidade de encontrar metodos que permitam reunir e organizar os conhecimentos, a partir do reconhecimento da complexidade do jogo de Futebol e das propriedades de interaccao dinâmica das equipas implicadas, enquanto conjuntos ou totalidades. No presente artigo pretendemos evidenciar que a abordagem sistemica do jogo de Futebol constitui uma importante referencia a considerar nos processos de ensino e treino do Futebol, na medida em que oferece a possibilidade de identificar e avaliar accoes/sequencias de jogo que, peia sua frequente ocorrencia, ou por induzirem desequilibrios (ofensivos e defensivos) importantes, se afiguram representativas da dinâmica das partidas.

Performance analysis in soccer: a Cartesian coordinates based approach using RoboCup data

In soccer, like in business, results are often the best indicator of a team’s performance in a certain competition but insufficient to a coach to asses his team performance. As a consequence, measurement tools play an important role in this particular field. In this research work, a performance tool for soccer, based only in Cartesian coordinates is presented. Capable of calculating final game statistics, suisber of shots, the calculus methodology analyzes the game in a sequential manner, starting with the identification of the kick event (the basis for detecting all events), which is related with a positive variation in the ball’s velocity vector. The achieved results were quite satisfactory, mainly due to the number of successfully detected events in the validation process (based on manual annotation). For the majority of the statistics, these values are above 92% and only in the case of shots do these values drop to numbers between 74 and 85%. In the future, this methodology could be improved, especially regarding the shot statistics, integrated with a real-time localization system, or expanded for other collective sports games, such as hockey or basketball.

Effects of Prolonged Intermittent Exercise on Perceptual-Cognitive Processes.

PURPOSE The visual search behaviors and thought processes underpinning anticipation and how these are influenced by intermittent exercise were examined in high- and low-level soccer players. METHODS High-level (n = 8) and low-level (n = 8) players completed a soccer-specific, intermittent exercise protocol that simulated the demands of a match while responding to filmed sequences of offensive play. HR, blood lactate concentrations, anticipation performance, visual search behaviors, and immediate retrospective verbal reports were assessed. RESULTS High-level players demonstrated superior anticipation compared with low-level counterparts, but both groups showed reduced accuracy across the exercise protocol. Mean HR and blood lactate values increased significantly from the beginning to the end of each half of the match (P < 0.05). Visual search data revealed significant group-test session interactions for the number of locations (P < 0.0001), mean fixation durations (P = 0.003), and number of fixations (P < 0.0001). When compared with low-level participants, high-level players used more fixations of shorter duration to more locations at the beginning of each half; whereas at the end of the exercise protocol, they used fewer fixations of longer duration to a lower number of locations. There was a significant group-type of statement-test session interaction (P = 0.001) for the verbal report data. High-level participants generated a great number of evaluation, prediction (in the beginning of the second half), and deep planning statements (during the first and the last test sessions). In contrast, low-level players used more superficial cognition statements than high-level individuals in both halves. CONCLUSION The intermittent exercise induced changes in perceptual-cognitive processes in both groups, although high-level players exhibited superior anticipation across test sessions accompanied by more effective search behaviors and elaborate thought processes.

Comparing Tactical Behaviour of Soccer Players in 3 vs. 3 and 6 vs. 6 Small-Sided Games

Abstract The present study aimed to compare players’ tactical behaviour in 3 vs. 3 and 6 vs. 6 soccer small-sided games (SSGs). The sample comprised 3,482 tactical actions performed by 18 U-11 youth soccer players from a Portuguese club, in 3 vs. 3 and 6 vs. 6 SSGs. All participants played eight minutes in both situations and field size was adapted according to the number of players involved (30 m x 19.5 m for 3 vs. 3 and 60 m x 39 m for 6 vs. 6). The System of Tactical Assessment in Soccer (FUT-SAT) was used for data collection and analyses. Descriptive analysis was conducted to verify frequencies and percentages of the variables assessed. The chi-squared (χ2) test was performed to compare the frequencies of the variables between 3 vs. 3 and 6 vs. 6 SSGs and Standardized Residuals (e) were used to examine the influence of the frequency of one or more variables within 3 vs. 3 and 6 vs. 6 SSGs. Data treatment was performed through SPSS for Windows®, version 18.0. Results indicated that players displayed safer behaviours in 6 vs. 6 SSG and more aggressive behaviours in 3 vs. 3 SSG. Findings can aid coaches and teachers to develop different players’ tactical skills according to the chosen SSG (3 vs. 3 or 6 vs. 6) form.

SoccerEye: A Software Solution to Observe and Record Behaviours in Sport Settings

In soccer, the need for direct observation of tactical behaviour has led to continuous technological advances in motion recording software. Here we present SoccerEye, a sports-specific software tool to observe and record the behaviour of soccer players in their natural setting and in real time. The software was written in Visual Basic Express 2010 and includes the following features: computerised coding, improved-quality recording, episodic sampling, the measurement of time, and diachronic analysis. Its configuration is well defined but allows for incorporation of ad hoc categories. Data can be exported in multiple generic formats, including the SDIS format for the analysis of interaction sequences with GSEQ software. However, by considering time and sequential decisions, SoccerEye itself tracks activity profiles and the dynamics of play. The greatest advantage of SoccerEye is the possibility to conduct diachronic analysis, which regards an event or multi event sequence in terms of change over time. This type of analysis takes into account the behaviour of a player and his or her team when facing the opponent, the space (pitch area) and time (starting time and duration) of each event, and other factors such as match status, match time, and competition stage. SoccerEye is a free- access user-friendly application that can be used to observe a single player or an entire team while controlling over the environment in which the observation takes place. This tool will hopefully contribute to the better understanding of the dynamics of soccer play.