Using network science to analyze football passing networks: dynamics, space, time and the multilayer nature of the game

From the diversity of applications of Network Science, in this Opinion Paper we are concerned about its potential to analyze one of the most extended group sports: Football (soccer in U.S. terminology). As we will see, Network Science allows addressing different aspects of the team organization and performance not captured by classical analyses based on the performance of individual players. The reason behind relies on the complex nature of the game, which, paraphrasing the foundational paradigm of complexity sciences "can not be analyzed by looking at its components (i.e., players) individually but, on the contrary, considering the system as a whole" or, in the classical words of after-match interviews "it's not just me, it's the team".Comment: 7 pages, 1 figur

Open source technologies involved in constructing a web-based football information system

The current information systems and match analysis software associated to professional football output a huge amount of statistics. Many football professionals are particularly interested in real time information about the tactical plan occurring during the match, and the relations between that information and what was prepared in the training sessions. It is fundamental to have on the bench, and on-the-fly, the most relevant information each time they have to take a decision. In this paper, we present a set of open source technologies involved in building a multi-platform web based integrated football information system, supported in three main modules: user interfaces, databases, and the tactical plan detection and classification. We show that the selected technologies are suitable for those modules, allowing field occurrences to trigger meaningful information

Spatial movement pattern recognition in soccer based on relative player movements

Knowledge of spatial movement patterns in soccer occurring on a regular basis can give a soccer coach, analyst or reporter insights in the playing style or tactics of a group of players or team. Furthermore, it can support a coach to better prepare for a soccer match by analysing (trained) movement patterns of both his own as well as opponent players. We explore the use of the Qualitative Trajectory Calculus (QTC), a spatiotemporal qualitative calculus describing the relative movement between objects, for spatial movement pattern recognition of players movements in soccer. The proposed method allows for the recognition of spatial movement patterns that occur on different parts of the field and/or at different spatial scales. Furthermore, the Levenshtein distance metric supports the recognition of similar movements that occur at different speeds and enables the comparison of movements that have different temporal lengths. We first present the basics of the calculus, and subsequently illustrate its applicability with a real soccer case. To that end, we present a situation where a user chooses the movements of two players during 20 seconds of a real soccer match of a 2016-2017 professional soccer competition as a reference fragment. Following a pattern matching procedure, we describe all other fragments with QTC and calculate their distance with the QTC representation of the reference fragment. The top-k most similar fragments of the same match are presented and validated by means of a duo-trio test. The analyses show the potential of QTC for spatial movement pattern recognition in soccer

How players exploit variability and regularity of game actions in female volleyball teams

Variability analysis has been used to understand how competitive constraints shape different behaviours in team sports. In this study, we analysed and compared variability of tactical performance indices in players within complex I at two different competitive levels in volleyball. We also examined whether variability was influenced by set type and period. Eight matches from the 2012 Olympics competition and from the Portuguese national league in the 2014–2015 season were analysed (1496 rallies). Variability of setting conditions, attack zone, attack tempo and block opposition was assessed using Shannon entropy measures. Magnitude-based inferences were used to analyse the practical significance of compared values of selected variables. Results showed differences between elite and national teams for all variables, which were co-adapted to the competitive constraints of set type and set periods. Elite teams exploited system stability in setting conditions and block opposition, but greater unpredictability in zone and tempo of attack. These findings suggest that uncertainty in attacking actions was a key factor that could only be achieved with greater performance stability in other game actions. Data suggested how coaches could help setters develop the capacity to play at faster tempos, diversifying attack zones, especially at critical moments in competition

Teams' coordination dynamics reveals performance outcomes of open play attacks in professional soccer

Mestrado em Treino de Alto RendimentoThe aim of this study was to examine whether teams’ coordination dynamics reveals the success of the attacking and defending performance outcomes. The players’ trajectories from 8 matches were recorded, 242 open play attacks ending in defensive success and 122 ending in attacking success were selected for analysis. Four compound variables (surface area, stretch index, length and width) were used to capture the overall teams’ dispersion behaviors during each play. The results showed that attacking teams presented larger values than the defending teams. Only the width measure revealed significant superior values for both teams when the attacks ended with defensive success. The positive correlations values between teams in every measure showed that, teams spent most of the time contracting and expanding together. However, only the length correlation value presented significant higher values when attacks ended with attacking success than defensive success. The relative analyses showed an equal distribution across every mode of coordination between teams when the attacks ended with defensive success. A lead-lag relation was observed when attacks ended in attacking success, with defending teams temporally leading the spatial contraction-expansion relationship. Findings suggest that attacking teams succeed when break symmetry with defending teams, exploiting subtle temporal lags in coordination between teams.O objetivo deste estudo foi examinar se a coordenação dinâmica das equipas revela sucesso atacante e defensivo. As trajetórias dos jogadores foram capturadas de 8 jogos e foram selecionados 242 ataques terminados em sucesso defensivo e 122 em sucesso ofensivo. Para capturar os comportamentos de dispersão das equipa em cada jogada, utilizaram-se 4 variáveis de dispersão (área de equipa, stretch index, comprimento e largura). Os resultados mostraram que a equipa atacante apresenta valores superiores à equipa defensora. Apenas a largura revelou valores superiores significantes para as duas equipas em ataques de sucesso defensivo. Os valores de correlação positivos entre as equipas revelam que as duas equipas contraem e expandem ao mesmo tempo. Contudo, apenas a correlação do comprimento apresentou valores significantes superiores nos ataques terminados em sucesso atacante do quem em sucesso defensivo. As análises relativas mostraram uma distribuição igual entre equipas ao longo de cada modo de coordenação, quando os ataques terminaram em sucesso defensivo. Observou-se uma relação de "lead-lag" quando os ataques terminaram em sucesso atacante, com a relação espacial de contração-expansão a ser liderada temporalmente pela equipa defensora. Os resultados sugerem que o sucesso das equipas atacantes surge de uma quebra de simetria com as equipas defensoras, explorando atrasos temporais subtis na coordenação entre equipas

The emergence of team synchronization during the soccer match : understanding the influence of the level of opposition, game phase and field zone

Mestrado em Treino de Alto RendimentoThe aim of this study was to examine whether the level of opposition, game phase and field zone influence whole team synchronization. Positional data from six friendly soccer matches against opponents of different level were collected using GPS units. Game phase and dominant field zone were further noted using observational video analysis. The whole team synchronization was assessed in each game using the cluster phase method. Results revealed that the opponent team level had a major impact on the degree of teams synchronization, while the influence of game phase and dominant field zone is very limited. The analyses of movement synchronization both in longitudinal and lateral displacement axes consistently revealed that competing against amateur opponents tend to decrease the degree of team synchrony. Differences between game-phase occurred only in games against 1st league teams. In overall, higher values of team synchronization were found in matches against opponents of similar higher level and in the defensive phases. These findings suggested that the selection of the opponent teams during pre-season friendly matches is a critical factor, even more since demarcated differences in team synchronization between game phases appeared only when competing against opponents of similar higher level.Com este estudo pretendeu avaliar-se se o nível de oposição, a fase de jogo e o sector do campo influenciam os níveis de sincronização da equipa. Os dados posicionais de seis jogos amigáveis contra adversários de diferentes níveis foram capturados com a utilização de unidades de GPS. A fase de jogo e a zona dominante do campo foram registadas posteriormente através da análise observacional de vídeo. O grau de sincronização da equipa enquanto um todo foi calculado para cada jogo com recurso ao método cluster phase. Os resultados revelaram que o nível de oposição exerce uma influência clara no grau de sincronização das equipas enquanto que a influência do sector do campo e da fase de jogo é limitada. Diferenças entre a fase de jogo ocorreram apenas em jogos contra equipas da primeira liga. No geral, foram encontrados valores mais altos de sincronização colectiva em jogos frente a opositores de nível igualmente mais elevado e na fase de jogo defensiva. Estas descobertas sugeriram que a selecção das equipas adversárias para os jogos amigáveis durante a pré-época é um factor crítico, enaltecido pelo facto de os resultados terem demonstrado diferenças na sincronização colectiva entre fases de jogo somente frente a adversários de nível igualmente superior

Effects of manipulations of player numbers vs. field dimensions on inter-individual coordination during small-sided games in youth football

The relative space per player formulated in small-sided and conditioned games can be manipulated either by promoting variations in player numbers or by modifying field dimensions. In this study we analysed how the same relative spaces per player, obtained through manipulations of player numbers and field dimensions, influenced inter-individual coordination. The positional data (GPS, 10 Hz) of 24 U-15 yrs performing in three different relative spaces per player (118, 133 and 152m2) was used. Inter-individual behavioural measures included: (i) effective relative space per player, (ii) radius of free movement; (iii) numerical relations inside each player’s relative space per player; and (iv) players’ spatial distribution variability. Magnitude-based inferences were used to analyse the practical significance of the selected variables. Results showed that manipulations of player numbers elicited more free space in the vicinity of each player. However, more advantageous numerical relations adjacent to each individual player and broader individual spatial distributions on field were observed during manipulations of field dimensions. These findings highlight the complex nature of performance behaviours captured by the co-adaptation of players to surrounding spatial constraints. Sport pedagogists should carefully evaluate the use of player numbers and field dimensions as strategies to simulate constraints of specific game contexts

Explorative study on patterns of same structure in male and female matches from elite spanish soccer

I Brage finner du siste tekst-versjon av artikkelen, og den kan inneholde ubetydelige forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på www.ingentaconnect.com / In Brage you'll find the final text version of the article, and it may contain insignificant differences from the journal's pdf version. The definitive version is available at www.ingentaconnect.comThe aim of this study was to explore emergent patterns of game structure in male and female matches from elite soccer by using playing distances measured according to the ball location. Archive data based on carefully selected four male and four female matches from elite Spanish soccer seasons 2002-3, 2003-4 and 2004-5 were collected by help of AMISCO PRO® system. Differences across six ball locations were found in mean playing length (χ2 5=328.1 and 520.9, P<0.001) and playing width (χ2 5=39.6 and 26.9, P<0.001) from male and female matches, respectively. Both sexes displayed similar movements in playing length that vary with stretch-contraction-stretch patterns and in playing width that vary with opposite patterns of contraction-stretch-contraction, but these patterns varied to a significantly greater extent in male matches. For example, male matches (mean=44.93±8.34 m) produced significantly (U=128564.0, z=-8.2, P<0.001) longer playing width during transition phase in midfield compared with female matches (mean=41.80±8.00 m). Results suggest that female matches produced less favourable patterns of game structure with fewer penetration opportunities than male matches. Specific suggestions for coaching intervention were given. This study demonstrates the potential of analysing playing distances according to the ball location for studying patterns of game structure in real soccer matches.Seksjon for coaching og psykologi / Department of Coaching and Psycholog

O efeito das substituições no comportamento tático e no rendimento físico dos jogadores profissionais de futebol de alto rendimento

O objetivo deste estudo foi analisar o impacto das substituições no comportamento tático e no rendimento físico de jogadores profissionais de futebol da primeira liga inglesa. Foram analisadas 40 substituições diretas de jogadores das posições de médios centro, extremos e avançados, ocorridas durante a segunda parte dos jogos. Para captar o comportamento tático individual dos jogadores foram utilizadas duas variáveis compostas: a variação da distância de cada jogador ao seu locus de referência espacial e a distribuição espacial dos deslocamentos de cada jogador (heat map). A partir destas variáveis foram calculadas a média, desvio padrão e coeficiente de variação, assim como duas medidas de entropia - que permitem mensurar a regularidade e a variabilidade/imprevisibilidade do comportamento tático individual de cada jogador. Para captar o rendimento físico dos jogadores foi utilizada a distância total percorrida e a distância percorrida em cinco categorias de intensidade. Os médios centro e os avançados substituídos apresentaram uma diminuição da imprevisibilidade no período inicial do jogo comparativamente com o período anterior à substituição. Foi também evidente a tendência para ocorrer uma diminuição do rendimento físico nos jogadores substituídos entre o período inicial de jogo e o período imediatamente anterior à substituição. Da mesma forma, para os médios e os extremos, os jogadores quando entraram na qualidade de substitutos apresentam também um maior rendimento físico que os jogadores substituídos. O jogador da posição do substituto/substituído, que permaneceu em campo apresentou também menor rendimento físico que os substitutos. Estes resultados sugerem que as motivações táticas justificam as substituições de médios centro e avançados e as motivações físicas justificam as substituições de médios centro e extremos.The aim of this study is to investigate the impact of substitutions in the behavior and physical performance of professional football players. The analysis was focused on forty direct substitutions of players that performed as central midfielders, external midfielders and forwards, occurring in the second half of the match. Player’s tactical behavior was calculated using two variables: movement variability present in distance over time, considered as a player positional spatial reference (locus) and in player’s action zones (heat map). Mean, standard deviation and coefficient of variation were calculated from these variations, as well as two entropy measures – which allow us to measure regularity and unpredictability/variability of tactical behavior for each player. Player’s physical performance was calculated using total distance and distance covered in five categories of movement intensity. Results showed that central midfielders and forwards replaced decreased unpredictability in previous period of substitution. The trend for having a decrease in substituted player’s physical performance was clear in previous period of substitution. In the same way, substitute players that performed as central midfielders and external midfielder showed better physical performance than players they replaced. The player of the same position of substitute/ substituted, that remained in the pitch, showed less workrate than replaced players. These findings suggest that tactical motivations justified the substitutions for central midfielders, and forwards and physical motivations justified substitutions for central midfielders and external midfielders