Daniel Barreira

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.

Goal Scoring in Soccer: A Polar Coordinate Analysis of Motor Skills Used by Lionel Messi.

Soccer research has traditionally focused on technical and tactical aspects of team play, but few studies have analyzed motor skills in individual actions, such as goal scoring. The objective of this study was to investigate how Lionel Messi, one of the worlds top soccer players, uses his motor skills and laterality in individual attacking actions resulting in a goal. We analyzed 103 goals scored by Messi between over a decade in three competitions: La Liga (n = 74), Copa del Rey (n = 8), and the UEFA Champions League (n = 21). We used an ad-hoc observation instrument (OSMOS-soccer player) comprising 10 criteria and 50 categories; polar coordinate analysis, a powerful data reduction technique, revealed significant associations for body part and orientation, foot contact zone, turn direction, and locomotion. No significant associations were observed for pitch area or interaction with opponents. Our analysis confirms significant associations between different aspects of motor skill use by Messi immediately before scoring, namely use of lower limbs, foot contact zones, turn direction, use of wings, and orientation of body to move toward the goal. Studies of motor skills in soccer could shed light on the qualities that make certain players unique.

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.

The Influence of Scoring Targets and Outer-Floaters on Attacking and Defending Team Dispersion, Shape and Creation of Space During Small-Sided Soccer Games

Abstract The effect of altered game formats on team performances during soccer practice can be harnessed by coaches to stimulate specific tactical behaviours. The aim of the present study was to analyse the influence of using (i) small goals [SG], (ii) goalkeepers [7G] and (iii) floaters [7GF] on the dispersion, shape and available space of teams during small-sided games (SSGs). Twenty-four male soccer players were distributed into four teams composed of five players, two goalkeepers and two floaters that performed six SSG bouts of 6 min, interspersed with 6 min of passive recovery. Offensive and defensive phases were also analysed separately in order to verify the preservation of basic principles of attacking (teams more stretched to create free space) and defending (teams more compact to tie-up space) during SSGs. The variables used to characterize the collective behaviour were: length [L], width [W], team shape [Sh], and team separateness [TS]. Results revealed that the teams showed different collective behaviours depending on SSG format and a playing phase: a) L and W were higher in attack than in defence in all SSGs; b) team shapes were more elongated in defence in all SSGs except SG; c) the space separating players from their closest opponents (TS) was shorter in 7G; and d) SG and 7GF elicited greater defensive openness due to increased team width. The results suggest that manipulating task constraints, such as goal size, presence or absence of goalkeepers and floaters can be harnessed by coaches to shape distinct team tactical behaviours in SSGs while preserving the basic principles of attacking and defending.

How elite-level soccer dynamics has evolved over the last three decades?: input from generalizability theory

Soccer dynamics have evolved in response to environmental fac- tors such as match status, type of competition, and competition stage. Ob- servational analysis has shed light into the behavior of players, but few re- searchers have looked at the complexity of the interactions between players and their teams over time. Here we investigated the variables in;uencing the patterns of play and the evolution of tactical and technical behaviors through the last three decades. A retrospective inferential study was applied. SoccerEye observational instrument and recording software were used to observe and record 45 matches and 6791 attacks from European and World Cup semi-<nals and <nals between 1982 and 2010. Publicly available broadcast footage was used for the analysis. Generalizability theory was used as the basis of the statistical analysis. =e patterns of pl ay changed by 31.4% from 1982 to 2010. Team dynamics were in;uenced by match s tatus (28.0%), competition stage (26.5%), and game period (18.1%). During the last decade (2002-2010), teams tended to use less the dribble and running with the ball but to increase long passing rate. During 2002-2010 decade, the frequency of attacks down the wings was higher than in 1982-2000, probably a result of the numerical disadvantage of the attacking team in the area of play. Soccer dynamics have changed towards more teamwork and less individual work over the last 30 years. However, not only time, but also match status, competition stage, and game period have in; uenced the patterns of play.

Differences in strength and speed demands between 4v4 and 8v8 small-sided football games

ABSTRACT The aims of this study were (i) to characterise the acceleration demands of two different formats of small-sided game (SSG), i.e., 4v4 + goalkeepers (4v4 + GK) and 8v8 + goalkeepers (8v8 + GK); (ii) to analyse the correlation between performance in power-based tests and acceleration-based physical loading during the two different SSG formats and (iii) to analyse the neuromuscular-induced fatigue. Eighteen adult male footballers participated in the study (20.7 ± 1.0 years, 178 ± 5 cm and 71.4 ± 2.1 kg). Baseline measurements were obtained from countermovement jumps, 15 s repeated jumps and 5 and 15 m sprints. A total of 36 min was analysed for each SSG (4v4 + GK: two sets of 3 × 6 min, and 8v8 + GK: 2 × 18 min). Heart rate, blood lactate, perceived exertion and movement pattern (GPS) were analysed. Distances covered by very-high-intensity activities and very-high-speed running were lower in 4v4 + GK than in 8v8 + GK (effect sizes (ES) = −0.69 ± 0.67 and −1.04 ± 0.67, respectively; very likely), while accelerations and decelerations were higher in 4v4 + GK than in 8v8 + GK (ES = 1.13–1.52; almost certainly). Blood lactate concentrations were higher (ES = 1.40 ± 0.58; almost certainly) and players perceived themselves to be more tired (ES = 0.80–2.31; almost certainly) after 4v4 + GK than after 8v8 + GK. Sprint ability in 5 and 15 m tests decreased (ES = 0.87 ± 0.58 and 0.89 ± 0.58, respectively; almost certainly) only after 4v4 + GK. This SSG format appeared more demanding in relation to repetitions and fatigue development of muscle power-based actions than 8v8 + GK. It may therefore be logical to use the former type of SSG to target development of power-related football actions.

Influence of opponent standard on activity profile and fatigue development during preseasonal friendly soccer matches: a team study

ABSTRACT We examined the influence of competitive standard of the opponent on activity profile and fatigue during preseason friendly soccer matches. Time motion analysis was performed in a male professional soccer team (N = 14) during six friendly games played against professional, semi-professional and amateur-level opponents (PL, SPL and AL). The reference team covered higher acceleration distance, acceleration and deceleration > 2 m· s−2 distance against PL than AL (ES = 0.77 to 0.91). Acceleration and deceleration distance > 2 m· s−2 was also higher (ES = 0.66 to 0.84) against SPL than AL. Greater decreases in total distance, distance> 16 km· h−1 and > 22 km· h−1, total acceleration and deceleration, acceleration and deceleration distance > 2 m· s−2 (ES = 0.84 to 2.20) were also observed during PL compared to AL opponent. Playing against a stronger opponent seems to be more physically demanding, with special emphasis on events related with change of velocity (accelerations and decelerations). Declines in physical performance appear more evident against a higher opponent.

Como tem a dinâmica do Futebol de elite evoluído ao longo das últimas três décadas?: aplicação da Teoria da Generabilidade

Soccer dynamics have evolved in response to environmental fac- tors such as match status, type of competition, and competition stage. Ob- servational analysis has shed light into the behavior of players, but few re- searchers have looked at the complexity of the interactions between players and their teams over time. Here we investigated the variables in;uencing the patterns of play and the evolution of tactical and technical behaviors through the last three decades. A retrospective inferential study was applied. SoccerEye observational instrument and recording software were used to observe and record 45 matches and 6791 attacks from European and World Cup semi-<nals and <nals between 1982 and 2010. Publicly available broadcast footage was used for the analysis. Generalizability theory was used as the basis of the statistical analysis. =e patterns of pl ay changed by 31.4% from 1982 to 2010. Team dynamics were in;uenced by match s tatus (28.0%), competition stage (26.5%), and game period (18.1%). During the last decade (2002-2010), teams tended to use less the dribble and running with the ball but to increase long passing rate. During 2002-2010 decade, the frequency of attacks down the wings was higher than in 1982-2000, probably a result of the numerical disadvantage of the attacking team in the area of play. Soccer dynamics have changed towards more teamwork and less individual work over the last 30 years. However, not only time, but also match status, competition stage, and game period have in; uenced the patterns of play.

The inter-individual relationship between training status and activity pattern during small-sided and full-sized games in professional male football players

ABSTRACT Objectives: We analysed the inter-individual relationship between training status and activity pattern in small-sided games (SSG) and full-sized games (FG). Methods: Fourteen Italian elite male senior football players were monitored during four training sessions incorporating SSG, and six FG, during the pre-season. Baseline measurements included, countermovement jump (CMJ), 5-m sprint time and Yo-Yo intermittent recovery test level 1 distance (YYIR1). Activity pattern was collected via 15-Hz global positioning system with 100-Hz accelerometer integrated. Results: Maximum accelerations (Accmax) and maximum decelerations (Decmax) showed moderate correlations (P < 0.05; r = 0.49 and 0.52) between SSG and FG. YYIR1 correlated with total distance covered (TD) in both SSG and FG (P < 0.05; r = 0.42 to 0.57) and with high-intensity distance (HIR) during FG (P < 0.05; r = 0.46 ± 0.38). CMJ showed positive correlations with TD, Accmax, Decmax, total accelerations (Acctot) and total decelerations (Dectot) during FG (P < 0.05; r = 0.40 ± 0.38, 0.41 ± 0.40, 0.46 ± 0.38, 0.65 ± 0.29, 0.57 ± 0.33). Multiple regression analysis revealed Decmax during SSG, as significant predictor of physical performance during FG, explaining a significant amount of variation in HIR, very-high speed running, Accmax and Decmax (P < 0.05; R2 = 0.49, 0.44, 0.26 and 0.49) during FG. Conclusions: SSG seems more effective to enhance muscular efforts occurring during FG, such as accelerations and decelerations, rather than speed patterns. Specifically, Decmax distance imposed during SSG was identified as the predictor of players’ movement patterns during FG. Thus, importance of eccentric strength (i.e. imposed when decelerating) to achieve football-specific fitness is emphasised. These findings may assist coaches and any football practitioners for pre-season programming.

Variability of activity profile during medium-sided games in professional soccer

BACKGROUND In Southern European countries it is very frequent to perform medium-sized games (MSG) as last training drill. We analyzed the individual variability and changes in activity patterns during MSG throughout the preseason. METHODS Activity profile during MSGs (10v10+goalkeepers, duration: 10-min, field length: 50 m, width: 90 m, area per player: 204.5 m2) was quantified using a GPS in 14 professional male players (6 defenders, 5 midfielders 5 and attackers). RESULTS Inter-individual variability was higher for high-intensity (HIR), very-high speed (VHS), maximum acceleration (Accmax) and maximum deceleration (Decmax) distance (CV=25.2 to 43.3%), compared to total distance (TD), total acceleration (Acctot) and total deceleration (Dectot) distance (CV= 8.3 to 18.3%). Defenders showed higher variability in TD, HIR, VHS, Acctot and Dectot (ES= 1.30 to 11.28) compared to the other field positions, whereas attackers showed higher variability in HIR, VHS Accmax and Decmax (ES=-4.92 to 2.07) than other the field positions. Variability in TD regularly increased (ES= -2.13 to -0.91) towards the end of the preseason, while HIR and VHS variability tended to increase over the 3rd and the 4th preseason week (ES=-0.94 to -3.05). However, the behavior of variability across the preseason period was more unpredictable for Acctot and Dectot, both decreasing in the 3rd week (ES= 0.70 to 1.20), while Decmax increased in the 4th week (ES=-0.91±0.59). CONCLUSIONS During MSGs, individual variability of activity differs among field positions, and tends to increase with either speed or acceleration intensity, underlining the need of an individualized approach for training load monitoring.