Inter-team variability in game play under critical game scenarios: a study in high-level men’s volleyball using social network analysis (Variabilidad entre equipos en el juego bajo escenarios críticos de juego: un estudio en voleibol masculino de alto ni

Critical scenarios are highly relevant to match analysis because they contribute to a better understanding of performance and provide essential information about team evolution. The goal of this study was to investigate inter-team variability in high-level men's volleyball during critical game scenarios (i.e., non-ideal setting conditions). Ten matches of the Men’s 2019 Volleyball Nations League Finals (Russia, USA, Poland, Brazil, Iran, France) were analyzed (n = 649 plays). Six independent Eigenvector Centrality networks were created (632 nodes; 3507 edges) using Social Network Analysis. When playing under critical scenarios the top two ranked teams differed in side-out attack. Specifically, the USA presented quick attacks, mainly in zone 4, using both the strong attack and exploration of the block. Conversely, Russia presented a game with high attack tempos and strong attacks. The USA and Russia also differed from Poland and Brazil in their approach to the game, the latter two teams using a varied attack (between strong, exploited, and directed attacks). After one error in attack, most teams presented a game style characterized by strong attacks, although Russia played using exploration of the block. The study shows teams competing at the same competitive level have differences in game patterns. The variability in approaches to the attack in critical scenarios (e.g., under non-ideal setting conditions and/or after consecutive attack errors) revealed that teams find different solutions for similar problems. Findings imply that match analysis should focus on exploring inter-team differences in gameplay while being cautious when interpreting aggregate data. Resumen. Los escenarios críticos son muy relevantes para el análisis de partidos porque contribuyen a una mejor comprensión del rendimiento y proporcionan información esencial sobre la evolución del equipo. El objetivo de este estudio fue investigar la variabilidad entre equipos en el voleibol masculino de alto nivel durante escenarios críticos de juego (principalmente en condiciones de colocación no ideales). Se analizaron diez partidos de las Finales de la Liga de Naciones de Voleibol Masculino 2019 (Rusia, Estados Unidos, Polonia, Brasil, Irán, Francia) (n=649 jugadas). Se crearon seis redes de centralidad de autovector independientes (632 nodos; 3507 bordes) utilizando el análisis de redes sociales. Cuando se jugaba en escenarios críticos, los dos mejores equipos clasificados diferían en ataque lateral. Específicamente, los Estados Unidos presentaron ataques rápidos, principalmente en la zona 4, utilizando tanto el fuerte ataque como la exploración del bloqueo. Por el contrario, Rusia presentó un juego con altos ritmos de ataque y ataques fuertes. Los Estados Unidos y Rusia también se diferenciaron de Polonia y Brasil en su enfoque del juego, los dos últimos equipos utilizando un ataque variado (entre ataques fuertes, explotados y dirigidos). Después de un error en ataque, la mayoría de los equipos presentaron un estilo de juego caracterizado por ataques fuertes, aunque Rusia jugó utilizando la exploración del bloque. El estudio muestra que los equipos que compiten al mismo nivel competitivo tienen diferencias en los patrones de juego. La variabilidad en los enfoques del ataque en escenarios críticos (en condiciones de colocación no ideales y/o después de errores de ataque consecutivos) reveló que los equipos encuentran diferentes soluciones para problemas similares. Los hallazgos implican que el análisis de partidos debe centrarse en explorar las diferencias entre equipos en el juego y, al mismo tiempo, ser cauteloso al interpretar los datos agregados.

Expertise and the work of football match analysts in TV sport broadcasts

In this paper we describe expertise as a way of seeing. We use match analysis `punditry’ as a setting to show how professional vision is interactionally achieved in TV sport broadcasts through environmentally coupled gestures enhanced by camera actions and a new technology of vision called telestrator. The paper is based on data from video sequences of (English) football TV broadcasts where the pundit shows to the TV host in the studio and to the non-expert audience at home what happened during a football match. We argue that the transparency of seeing is the product of an artfully instructed process whereby the pundit shows what should be seen, how it should be made accountable, and what the audience should expect in order to fully appreciate what they see. The paper shows how broadcasted match analysis expertise interactionally achieves this through the time-critical linking of talk, gesture, and technological environment.

High-intensity curvilinear movements’ relevance in semi-professional soccer: An approach from principal components analysis

Due to the high number of variables reported from tracking systems, the interest in data reduction techniques has grown. To date, principal component analysis (PCA) has been performed in soccer, but since the results depend on the variables included, a lack of objectivity continues to be of concern. The aim of this study was to highlight the variables that compose the principal components (PC) in semi-professional soccer, including all variables extracted from tracking systems. Data were collected from a semi-professional Spanish team that participated in 10 matches. From more than 250 variables, the PCA grouped a total of 19 variables in six PCs, explaining 72% of players’ external load. All variables were related to centripetal force, high intensity running, and high-intensity efforts and short efforts. Interestingly, the first PC was composed of four variables related to centripetal force. The current exploratory analysis indicated that, in addition to traditional high-intensity displacement variables, force measures should also be considered in soccer match analysis due to their effect on a player’s external load.

Perceptions of Football Analysts Goal-Scoring Opportunity Predictions: A Qualitative Case Study

This study aimed to understand the way tactical football analysts perceive the general match analysis issues and to analyze their tactical interpretation of the predictive models of conceded goal-scoring opportunities. Nine tactical analysts responded to the semi-structured interviews that included a general section on the match analysis and a specific one on the results of a study on goal-scoring opportunities conceded by a Spanish La Liga team. Following their transcription, the interviews were codified into categories by the two researchers using Atlas Ti® software. Subsequently, frequency count and co-occurrence analysis were performed based on the encodings. The content analysis reflected that analysts play a crucial role in the analysis of their own team and that of the opponent, the essential skills to exercise as a tactical analyst being “understanding of the game” and “clear observation methodology.” Based on the case study of the conceded goal-scoring opportunities, the major causes and/or solutions attributed by analysts in some of the predictive models were the adaptability of the “style of play” itself according to the “opponent” and “pressure after losing.”

112 ROBOT-ASSISTED MINIMALLY INVASIVE ESOPHAGECTOMY CAN BE PERFORMED EVEN IN LEARNING CURVE PERIOD; PROPENSITY SCORE MATCH ANALYSIS

Da Vinci Surgical System Xi was introduced in our institution in 2017. Since then we started robot-assisted minimally invasive esophagectomy (RAMIE) as private practice. Japanese national insurance system started to reimburse RAMIE in 2018. Since then, the number of RAMIE is explosively increasing. Currently the indication of RAMIE in our institution purely depends on machine availability. However, the real clinical benefit of RAMIE over conventional minimally invasive esophagectomy (MIE) remains unknown. Methods Between January 2015 and January 2020, data of 156 consecutive patients with esophageal carcinoma undergoing esophagectomy was retrospectively reviewed. After exclusion of 12 salvage esophagectomy for patients after definitive chemoradiotherapy (>50Gy), 10 mediastinoscopic esophagectomy, 5 esophagectomy without upper mediastinal dissection, 2 two-stage esophagectomy and 1 total pharyngo-laryngo-esophagectomy, 126 patients (46 RAMIE and 80 MIE) were included in the analysis. The 1:1 propensity score match analysis was performed to compare the short-term outcomes between RAMIE and MIE. Results After matching, 45 RAMIE and 45 MIE were analyzed. RAMIE took significantly longer thoracic operation time (370 min vs. 288 min; P < 0.0001). Intraoperative blood loss (80 g vs. 50 g; P = 0.0759), harvested thoracic nodes (22 vs 25; P = 0.1188), harvested upper mediastinal nodes (12 vs 12; P = 0.4233) were similar. RAMIE showed less severe postoperative morbidity (Clavien-Dindo Grade III or higher) (9% vs. 22%; P = 0.0810) and lower incidence of recurrent laryngeal nerve palsy (Clavien-Dindo Grade II or higher) (7% vs. 18%; P = 0.1076). There was no postoperative death in both groups. Conclusion Although this result contains our early learning curve period of RAMIE, short term outcome of RAMIE is acceptable from a safety point of view.

Collision with opponents—but not foul play—dominates injury mechanism in professional men’s basketball

Background To identify injury patterns and mechanisms in professional men’s basketball by means of video match analysis. Methods In Germany, injuries are registered with the statutory accident insurance for professional athletes (VBG) by clubs or club physicians as part of occupational accident reporting. Moderate and severe injuries (absence of > 7 days) sustained during basketball competition in one of four seasons (2014–2017 and 2018–2019) in the first or second national men’s league in Germany were prospectively analyzed using a newly developed standardized observation form. Season 2017–2018 was excluded because of missing video material. Results Video analysis included 175 (53%) of 329 moderate and severe match injuries. Contact patterns categorized according to the different body sites yielded eight groups of typical injury patterns: one each for the head, shoulders, and ankles, two for the thighs, and three for the knees. Injuries to the head (92%), ankles (76%), shoulders (70%), knees (47%), and thighs (32%) were mainly caused by direct contact. The injury proportion of foul play was 19%. Most injuries (61%) occurred in the central zone below the basket. More injuries occurred during the second (OR 1.8, p = 0.018) and fourth quarter (OR 1.8, p = 0.022) than during the first and third quarter of the match. Conclusion The eight identified injury patterns differed substantially in their mechanisms. Moderate and severe match injuries to the head, shoulders, knees, and ankles were mainly caused by collision with opponents and teammates. Thus, stricter rule enforcement is unlikely to facilitate safer match play.

Data-driven detection of counterpressing in professional football

Detecting counterpressing is an important task for any professional match-analyst in football (soccer), but is being done exclusively manually by observing video footage. The purpose of this paper is not only to automatically identify this strategy, but also to derive metrics that support coaches with the analysis of transition situations. Additionally, we want to infer objective influence factors for its success and assess the validity of peer-created rules of thumb established in by practitioners. Based on a combination of positional and event data we detect counterpressing situations as a supervised machine learning task. Together, with professional match-analysis experts we discussed and consolidated a consistent definition, extracted 134 features and manually labeled more than 20, 000 defensive transition situations from 97 professional football matches. The extreme gradient boosting model—with an area under the curve of $$87.4\%$$ 87.4 % on the labeled test data—enabled us to judge how quickly teams can win the ball back with counterpressing strategies, how many shots they create or allow immediately afterwards and to determine what the most important success drivers are. We applied this automatic detection on all matches from six full seasons of the German Bundesliga and quantified the defensive and offensive consequences when applying counterpressing for each team. Automating the task saves analysts a tremendous amount of time, standardizes the otherwise subjective task, and allows to identify trends within larger data-sets. We present an effective way of how the detection and the lessons learned from this investigation are integrated effectively into common match-analysis processes.