Jaime Sampaio

A Review on the Effects of Soccer Small-Sided Games

A Review on the Effects of Soccer Small-Sided Games Over the last years there has been a substantial growth in research related to specific training methods in soccer with a strong emphasis on the effects of small-sided games. The increase of research in this topic is coincident with the increase of popularity obtained by specific soccer conditioning, which involves training players to deal with soccer match situations. Given the limited time available for fitness training in soccer, the effectiveness of small-sided games as a conditioning stimulus needs to be optimized to allow players to compete at the highest level. Available studies indicate that physiological responses (e.g. heart rate, blood lactate concentration and rating of perceived exertion), tactical and technical skill requirements can be modified during small-sided games by altering factors such as the number of players, the size of the pitch, the rules of the game, and coach encouragement. However, because of the lack of consistency in small-sided games design, player fitness, age, ability, level of coach encouragement, and playing rules in each of these studies, it is difficult to make accurate conclusions on the influence of each of these factors separately.

The effects of situational variables on distance covered at various speeds in elite soccer

Abstract The aim of this study was to examine the effect of match location, quality of opposition, and match status on distance covered at various speeds in elite soccer. Twenty-seven Spanish Premier League matches played by a professional soccer team were monitored in the 2005–2006 season using a multiple-camera match analysis system. The dependent variables were the distance covered by players at different intensities. Data were analysed using a linear regression analysis with three independent variables: match status (i.e. whether the team was winning, losing or drawing), match location (i.e. playing at home or away), and quality of the opponents (strong or weak). The top-class players performed less high-intensity activity (>19.1 km · h−1) when winning than when they losing, but more distance was covered by walking and jogging when winning. For each minute winning, the distance covered at submaximal or maximal intensities decreased by 1 m (P<0.05) compared with each minute losing. For each minute winning, the distance covered by walking and jogging increased by 2.1 m (P<0.05) compared with each minute losing. The home teams covered a greater distance than away teams during low-intensity activity (<14.1 km · h−1) (P<0.01). Finally, the better the quality of the opponent, the higher the distance covered by walking and jogging. Our findings emphasize the need for match analysts and coaches to consider the independent and interactive effects of match location, quality of opposition, and match status during assessment of the physical component of football performance.

Discriminant analysis of game-related statistics between basketball guards, forwards and centres in three professional leagues

Abstract The aim of the present paper was to examine the differences in game-related statistics between basketball guards, forwards and centres playing in three professional leagues: National Basketball Association (NBA, superior level) in the USA, Associación de Clubs de Baloncesto (ACB, one of the best European leagues) in Spain and Liga de Clubes de Basquetebol (LCB, inferior level) in Portugal. We reasoned that the knowledge of these differences could allow the coaches to better establish and monitor playing patterns and increase the effectiveness of the player recruitment process. Archival data was gathered for the 2000–2001 play-off final series of the NBA (five games), ACB (three games) and LCB (four games). For players in each league, discriminant analysis was able to identify game-related statistics that maximized mean differences between playing positions (p<0.05). The interpretation of the obtained discriminant functions was based on examination of the structure coefficients greater than ∣0.30∣. In the LCB league, centres and guards were discriminated mainly in terms of defensive tasks, with emphasis on blocks (structure coefficient, SC=0.35) and defensive rebounds (SC=0.43) and a de-emphasis on unsuccessful 3-point field-goals (SC= − 0.37). In the ACB, centres and guards were discriminated by offensive tasks, with emphasis on assists (SC=0.52) and 3-point field-goals, both successful (SC=0.35) and unsuccessful (SC=0.35), and a de-emphasis on offensive rebounds (SC= − 0.44). Finally, in the NBA league guards and centres were discriminated by offensive tasks, with emphasis on offensive rebounds (SC=0.31) and a de-emphasis on assists (SC= − 0.37) and unsuccessful 3-point field-goals (SC= − 0.34). These three analyses provided high overall percentages of successful classification (86% for the LCB league, 74% for the ACB and 85% for the NBA). Generally, the players’ game-related statistics varied according to playing position, probably because of the well-known differences in the players’ anthropometric characteristics that conditioned the distance they play from the basket. Coaches can use these results to reinforce the importance of relying on different players’ contributions to team performance and evaluate players’ game performance according to their playing position. Conversely, these discriminant models could help in player recruitment and improve training programmes.

Basketball game-related statistics that discriminate between teams’ season-long success

Abstract The aim of the present study was to identify the game-related statistics that discriminate between season-long successful and unsuccessful basketball teams participating in the Spanish Basketball League (LEB1). The sample included all 145 average records per season from the 870 games played between the 2000–2001 and the 2005–2006 regular seasons. The following game-related statistics were gathered from the official box scores of the Spanish Basketball Federation: 2- and 3-point field-goal attempts (both successful and unsuccessful), free-throws (both successful and unsuccessful), defensive and offensive rebounds, assists, steals, turnovers, blocks (both made and received), and fouls (both committed and received). To control for season variability, all results were normalized to minutes played each season and then converted to z-scores. The results allowed discrimination between best and worst teams’ performances through the following game-related statistics: assists (SC=0.47), steals (SC=0.34), and blocks (SC=0.30). The function obtained correctly classified 82.4% of the cases. In conclusion, season-long performance may be supported by players’ and teams’ passing skills and defensive preparation.

Statistical analyses of basketball team performance: understanding teams’ wins and losses according to a different index of ball possessions

The aim of the present paper is to investigate the discriminatory power of game statistics between winning and losing teams in the Portuguese Professional Basketball League. Methodological issues concerning game rhythm contamination and data organization according to game type (regular season or play-off), game final outcome (win or loss), game location (home or away) and game final score differences are discussed. Archival data were obtained for the 1997-1998 and the 1998-1999 Portuguese Professional Basketball League seasons for (a) all 353 regular season home and away games and (b) all 56 play-off home and away games. Cluster analysis was conducted to establish, according to game final score differences, three different groups for the subsequent analysis (close games, with final score differences between 1 and 8 points; balanced games, with final score differences between 8 and 18 points and unbalanced games, with final score differences above 18 points). Afterwards, discriminant analysis was used to identify the game statistics that maximize mean differences between winning and losing teams according to previously defined factors (type, location, cluster groups). Obtained results allowed us to understand that in balanced and unbalanced games, losing teams performed poorly in all game statistics. In contrast, results from close games allowed us to identify different team performance profiles according to game type and location. Globally, regular season profile was best discriminated by successful free-throws, whereas play-offs profile was best discriminated by offensive rebounding. On the other hand, home wins were best discriminated by committed fouls whereas successful free-throws discriminated away wins. Coaches and players should be aware of these different profiles in order to increase specificity at the time of game planning and control.

Discriminative power of basketball game-related statistics by level of competition and sex.

The purpose of this study was to identify the basketball game-related statistics that best discriminate performances by sex of players and level of competition. Archival data were obtained from the International Basketball Federation boxscores for all games during mens senior (n = 62), mens junior (n = 64), womens senior (n = 62), and womens junior (n = 42) World Championships. The game-related statistics gathered included 2- and 3-point field-goals (both successful and unsuccessful), free-throws (both successful and unsuccessful), defensive and offensive rebounds, blocks, assists, fouls, steals and turnovers. For the analysis only the close games were selected (N = 105, 1 to 12 points difference). Mens teams were discriminated from womens teams by their higher percentage of blocks and lower percentage of steals and unsuccessful 2-point field goals. Junior teams were discriminated from senior teams by their lower percentage of assists and higher percentage of turnovers. In the two-factor interaction, the teams were mainly discriminated by the game-related statistics identified for level of competition.

Length, width and centroid distance as measures of teams tactical performance in youth football

Abstract Small-sided games are commonly used in training and teaching contexts of football. However, few studies have focused on the tactical implications of this type of drills. The aim of this study is to identify how tactical collective behaviour varies with age in different small-sided game formats. We investigated the in-game field position in three different age groups of youth football players [under-9 (n=10; age = 8.5±0.53), under-11 (n=10; age = 10.4±0.52) and under-13 (n=10; age = 12.7±0.48)], participating in two different small-sided game conditions (GK + 3×3 + GK and GK + 4×4 + GK). A team variable was created based on the players’ length per width ratio (lpwratio), and a match variable was calculated as the distance between the centroid of the two teams. Results show that team variable values were influenced by the age of the players, as younger teams tend to present a higher value of lpwratio in their dispersion on the pitch. The variability of this variable also showed a decrease for teams with older players, suggesting a more consistent application of the width (stretching and creating space) and concentration (compressing into a confined area) principles of play and reflecting a higher level of collective tactical behaviour. Match variable showed a larger centroid distance for the older age groups in comparison with the younger players in the GK + 3×3 + GK, while all age groups demonstrated similar large centroid distances in the GK + 4×4 + GK game format. These results suggest that length and width ratio and centroid distance are useful measures of tactical performance in small-sided games in youth football.

Competing with Lower Level Opponents Decreases Intra-Team Movement Synchronization and Time-Motion Demands during Pre-Season Soccer Matches

This study aimed to quantify the time-motion demands and intra-team movement synchronization during the pre-season matches of a professional soccer team according to the opposition level. Positional data from 20 players were captured during the first half of six pre-season matches of a Portuguese first league team. Time-motion demands were measured by the total distance covered and distance covered at different speed categories. Intra-team coordination was measured by calculating the relative phase of all pairs of outfield players. Afterwards, the percentage of time spent in the −30° to 30° bin (near-in-phase mode of coordination) was calculated for each dyad as a measure of space-time movement synchronization. Movement synchronization data were analyzed for the whole team, according to each dyad average speed and by groups of similar dyadic synchronization tendencies. Then, these data were compared according to the opponent team level (first league; second league; amateurs). Time-motion demands showed no differences in total distance covered per opposition levels, while matches opposing teams of superior level revealed more distance covered at very high intensity. Competing against superior level teams implied more time in synchronized behavior for the overall displacements and displacements at higher intensities. These findings suggest that playing against higher-level opponents (1st league teams) increased time-motion demands at high intensities in tandem with intra-team movement synchronization tendencies.

PHYSIOLOGICAL RESPONSES AND ACTIVITY PROFILES OF FOOTBALL SMALL-SIDED GAMES

Abstract Aguiar, MVD, Botelho, GMA, Gonçalves, BSV, and Sampaio, JE. Physiological responses and activity profiles of football small-sided games. J Strength Cond Res 27(5): 1287–1294, 2013—The aim of this study was to identify the acute physiological responses and activity profiles of football small-sided games (SSG) formats. Ten professional football players participated in 4 variations of SSG (2-, 3-, 4-, and 5-a-side) with an intermittent regime involving 3 × 6-minute bouts with 1 minute of passive planned rest in which the heart rate (HR), rating of perceived exertion (RPE), activity profile, and body load were recorded. The higher percentage of maximum HR values were found in 2- and 3-a-side formats (p ⩽ 0.05). The lowest RPE value was found at the 5-a-side, and the highest was found at the 2-a-side (13.48 ± 2.67 and 17.01 ± 1.80, respectively, p ⩽ 0.05). The distance covered in the 2-a-side format (598.97 ± 78.91 m) was smaller than in all other formats. The 2-a-side format presented the lowest number of sprints (0.71 ± 0.86) and the 3-a-side the highest (2.50 ± 1.65). Statistically significant differences were found across SSG in the total body load. The 4-a-side presented the highest and the 5-a-side the lowest values (95.18 ± 17.54 and 86.43 ± 14.47, respectively). The body load per minute declined each 2 minutes of play. Maintaining a constant area:player ratio, coaches can use lower number of players (2- and 3-a-side) to increase cardiovascular effects but use higher number of players (4- and 5-a-side) to increase variability and specificity according to the competition demands.

Explanations for the United States of America's dominance in basketball at the Beijing Olympic Games (2008)

Abstract Anecdotally, the fast pace at which the USA mens basketball team played at the 2008 Olympics was the main reason for their dominance, although there is no way of quantifying what a fast pace is or how it contributed to point differentials. The aim of this study was to examine the game-related statistics that discriminate between fast- and slow-paced games, as well as to identify key performance factors relating to point differentials. We analysed game-related statistics for each quarter of the eight games played by the USA using a k-means cluster analysis to classify game pace using ball possessions per game quarter. We then tested for differences in game statistics between slow- and fast-paced game quarters using analysis of variance and discriminant analysis. How differences in game-related statistics affected point differentials was examined using linear regression. The largest structure coefficient between game paces for the USA was for recovered balls (0.33, P < 0.001). The biggest contributors to the point differences in games were recovered balls (16.9, P < 0.001) and field goals (22.2, P < 0.001). We conclude that when the USA play a fast-paced game, they are able to recover more balls from opponents that they then turn into effective field-goal shooting.