Asier Zubillaga

Application of four different football match analysis systems: a comparative study.

Abstract Using a video-based time–motion analysis system, a semi-automatic multiple-camera system, and two commercially available GPS systems (GPS-1; 5 Hz and GPS-2; 1 Hz), we compared activity pattern and fatigue development in the same football match. Twenty football players competing in the Spanish second and third divisions participated in the study. Total distance covered during the match for the four systems was as follows: 10.83 ± 0.77 km (semi-automatic multiple-camera system, n = 20), 9.51 ± 0.74 km (video-based time–motion analysis system, n = 17), 10.72 ± 0.70 km (GPS-1, n = 18), and 9.52 ± 0.89 km (GPS-2, n = 13). Distance covered by high-intensity running for the four systems was as follows: 2.65 ± 0.53 km (semi-automatic multiple-camera system), 1.61 ± 0.37 km (video-based time–motion analysing system), 2.03 ± 0.60 km (GPS-1), and 1.66 ± 0.44 km (GPS-2). Distance covered by sprinting for the four systems was as follows: 0.38 ± 0.18 km (semi-automatic multiple-camera system), 0.42 ± 0.17 km (video-based time–motion analysing system), 0.37 ± 0.19 km (GPS-1), and 0.23 ± 0.16 km (GPS-2). All four systems demonstrated greater (P < 0.05) total distance covered and high-intensity running in the first 15-min period and less (P < 0.05) total distance covered and high-intensity running during the last 15-min period than all other 15-min intervals, with a reduction (P < 0.05) in high-intensity running from the first to the last 15-min period of 46 ± 19%, 37 ± 26%, 50 ± 26%, and 45 ± 27% for the semi-automatic multiple-camera system, video-based time–motion analysis system, GPS-1, and GPS-2, respectively. Our results show that the four systems were able to detect similar performance decrements during a football game and can be used to study game-induced fatigue. Rather large between-system differences were present in the determination of the absolute distances covered, meaning that any comparisons of results between different match analysis systems should be done with caution.

Examination of fatigue development in elite soccer in a hot environment: a multi-experimental approach

The study examines fatigue in elite soccer played in hot conditions. High‐profile soccer players (n=20) were studied during match play at ∼31 °C. Repeated sprint and jump performances were assessed in rested state and after a game and activity profile was examined. Additionally, heart rate (HR), blood lactate, muscle temperature and body mass changes were determined. Repeated sprint and jump performances were reduced (P<0.05) by 2.6% and 8.2%, respectively, after the game. The fatigue index in the repeated sprint test was 6.0±0.7% after the game compared with 1.7±1.0% at rest (P<0.05). High‐intensity running was 57±4% lower (P<0.05) during the last 15‐min interval of the game compared with the first 15‐min period. No differences were observed in mean HR or blood lactates between halves. Muscle temperature was 40.5±0.4 °C after the first half, which was 0.8±0.2 °C higher (P<0.05) than after the second half. Net fluid loss during the game was >2% of the body mass. Correlations were observed between net‐fluid loss and repeated sprint test fatigue index after the game (r=0.73, P<0.05) and Yo‐Yo intermittent recovery, level 1 test performance and high‐intensity running during the final 15 min of the game (r=0.51, P<0.05). The study provides direct evidence of compromised repeated sprint and jump performances induced by soccer match play and pronounced reduction in high‐intensity running toward the end of an elite game played in a hot environment. This fatigue could be associated training status and hyperthermia/dehydration.

Designing small-sided games for training tactical aspects in soccer: Extrapolating pitch sizes from full-size professional matches

Abstract The aims of this study were to examine the 1) individual playing area, 2) length and width of the rectangle encompassing the individual playing area and 3) distance between the goalkeepers and their nearest team-mates during professional soccer matches and compare these to previously reported pitch sizes for small-sided games (SSGs). Data were collected from four Spanish La Liga matches of the 2002–03 season, and notated post-event using the Amisco® system. The pitch sizes obtained from real matches were smaller and different from those used previously for SSGs. In addition, the current pitch sizes show significant (P < 0.001) effect of ball location in all variables examined. For example, overall individual playing area (F [5, 2562] = 19.99, P < 0.001, η2 = 0.04) varied significantly across six different zones of the pitch. Based on these empirical results, pitch sizes with individual playing areas ranging from 65 m2 to 110 m2 and length to width ratio of 1:1 and 1:1.3 are generally recommended for training tactical aspects according to different phases of play. It is possible to design SSGs with a more valid representation of the tactical conditions experienced in full-size matches and their use may improve the training effect of tactical aspects of match performance in soccer.

Analysis of entries into the penalty area as a performance indicator in soccer

Abstract This study examines entries into the penalty area as a performance indicator that distinguishes between winning, drawing and losing soccer teams. It assesses whether entries into the penalty area are influenced by match status, a players dismissal and the respective quality of the competing teams. Two observers analysed the relation between defensive and offensive strategies and their scoring consequences for all 64 matches played in the 2006 World Cup. Kappa values ranged between 0.93 and 0.98 for intra-reliability and between 0.88 and 0.98 for inter-reliability. It was found that winning teams received significantly fewer entries into their own penalty area (mean=41.42, s=11.86) than drawing (mean=50.07, s=14.75) and losing teams (mean=47.23, s=12.14). Teams that received more entries into their own penalty area than the opposing team were significantly more likely to concede a goal (P <0.001). Teams losing by one (mean=0.41, s=0.21), two (mean=0.42, s=0.26) or more than two goals (mean=0.34, s=0.13) received significantly fewer entries into the penalty area per minute than teams winning by one (mean=0.55, s=0.27) or two goals (mean=0.59, s=0.39). Teams with fewer players on the pitch received significantly more entries into the penalty area per minute than teams with more (mean=0.22, s=0.07) or the same number (mean=0.14, s=0.05) of players. Based on these results, it is suggested that teams should enter the opposing teams penalty area but should not allow their opponents to do the same. These results also highlight the significance of the dismissal of a player.

Attacking and defensive styles of play in soccer: analysis of Spanish and English elite teams

ABSTRACT 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.

Influence of Ball Position on Playing Space in Spanish Elite Women's Football Match-Play

The aims of this study were to examine the playing area in female football matches according to the position of the ball. We investigated: 1) the space between the two offside lines (the length), 2) the width, 3) the distance from the least advanced defender to the goal line in defensive activity, 4) the distance from the least advanced attacker to her goal line in attacking activity, 5) the distance between the goalkeeper and her nearest attacking team mate, and 6) the distance between the goalkeeper and her nearest defending team mate. With these measurements we were also able to obtain 7) the individual playing area used during female professional football matches. Data were collected during Spanish matches and notated post-event using the Amisco® system. A total of 2756 game situations were coded from four games. The distribution of players was significantly (p<0.001) wider and shallower when the ball was in the central areas of the field (37.07 m × 43.84 m “zone 3” and 36.36 m × 42.82 m “zone 4”) than when the ball was in a “building up play” zone (43.31 m × 39.24 m “zone 1”), and the finishing and scoring zone (48.14 m × 39.80 m “zone 6”). The values obtained for the individual playing area varied between 77.91 m2 and 96m2. The players stood further from the goals depending on the position of the ball. The spaces at the back of the defensive line changed from 45.75 m to 6.90 m (to the goal line) depending on the position of the ball. In addition, the spaces at the back of the less advanced attacking line changed from 16.45 m to 52.24 m, depending on the position of the ball. There were significant differences (p<0.05) in playing spaces between all zones. The results show that the spaces were significantly different depending on the ball position. Changes in playing space are presented as an important factor to consider when designing game-specific training activities for female football.

Influence of contextual variables on styles of play in soccer

ABSTRACT The aim of the present study was to evaluate the effect of match status, venue, and quality of opposition on the styles of play in soccer. Data were collected from 380 games of the English Premier League from the 2015–2016 season. Linear mixed models were applied to evaluate the influence of these contextual variables on membership scores for Direct Play, Counterattack, Maintenance, Build Up, Sustained Threat, Fast Tempo, Crossing, and High Pressure. The results showed that match status had a significant effect on the eight styles of play (all P < 0.001), venue had a significant effect on all styles of play (P < 0.01) except Counterattack and Maintenance, and quality of opposition had a significant effect on all styles of play (P < 0.05) except Counterattack. Moreover, the interaction between match status and quality of opposition, and venue and quality of opposition showed significant effects on some styles of play. The results of this study imply that contextual variables influence the use of styles of play in soccer match play. Consequently, this provides meaningful recommendations for practitioners in soccer.

Explorative Study on Patterns of Game Structure in Male and Female Matches from Elite Spanish Soccer

The 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 (χ25=328.1 and 520.9, P<0.001) and playing width (χ25=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.

Analysis of Small Game Areas of 4vs4 and 7vs7 in Spanish Professional Football

This study was originally published in Proceedings of the 2nd International Congress on Sports Sciences Research and Technology Support (PerSoccer-2014), pages 231-235.