Alberto Lorenzo

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.

Ball possession effectiveness in men's and women's elite basketball according to situational variables in different game periods

Abstract The aim of the present study was to identify the importance of basketball performance indicators in predicting the effectiveness of ball possessions in mens and womens basketball, when controlling for situational variables and game periods. The sample consisted of 7234 ball possessions, corresponding to 40 games from the Spanish professional leagues. The effects of the predictor variables on successful ball possessions according to game period were analysed using binary logistic regressions. Results from mens teams show interactions with number of passes and ending player during the first five minutes, with starting and ending zone, defensive systems, screens used and possession duration during the middle thirty minutes, and there were interactions with passes used, possession duration and players involved during the last five minutes. Results from womens teams show interactions with starting and ending zone, passes used, defensive systems and ending player during the first five minutes, and with starting and ending zone, and screens used during the middle thirty minutes. The results show no interaction with situational variables in mens basketball, while league stage was important during the middle thirty minutes and last five minutes in womens basketball, whereas match status was only important during the last five minutes.

Differences in Game-Related Statistics of Basketball Performance by Game Location for Men's Winning and Losing Teams:

The aim of the present study was to identify game-related statistics that differentiate winning and losing teams according to game location. The sample included 306 games of the 2004–2005 regular season of the Spanish professional mens league (ACB League). The independent variables were game location (home or away) and game result (win or loss). The game-related statistics registered were free throws (successful and unsuccessful), 2- and 3-point field goals (successful and unsuccessful), offensive and defensive rebounds, blocks, assists, fouls, steals, and turnovers. Descriptive and inferential analyses were done (one-way analysis of variance and discriminate analysis). The multivariate analysis showed that winning teams differ from losing teams in defensive rebounds (SC = .42) and in assists (SC = .38). Similarly, winning teams differ from losing teams when they play at home in defensive rebounds (SC = .40) and in assists (SC = .41). On the other hand, winning teams differ from losing teams when they play away in defensive rebounds (SC = .44), assists (SC = .30), successful 2-point field goals (SC = .31), and unsuccessful 3-point field goals (SC = –.35). Defensive rebounds and assists were the only game-related statistics common to all three analyses.

Effectiveness during ball screens in elite basketball games

Abstract Ball screens are one of the most frequently used tactical behaviour in elite basketball games. The aim of the present study was to identify their predictors of success related to time, space, players, and tasks performed. The sample was composed of 818 ball screens corresponding to 20 close games (mean differences in score of 3.1 ± 0.8 points) randomly selected from the playoff games of the Spanish Basketball League (2008–2011). Classification tree analysis (CHAID) was used to analyse which variable or combination of variables, better predicts effectiveness during ball screens. The main results allowed identifying interactions with dribbler actions after the screen and the orientation of the screen on the ball. The results showed no interaction with game quarter and quarter minute temporal-related variables in both analyses. The present findings allow improving coaches’ strategic plans that involve selecting the most appropriate offensive approach when performing ball screens.

Exploring the effects of substituting basketball players in high-level teams

ABSTRACT Substituting basketball players during competition is a key process to optimise collective performance. Available research on this topic is scarce, probably due to the difficulty in isolating these effects; thus, the aim of this study was to identify the temporal effects of substitutions in basketball (Spanish professional basketball league). The sample was composed of 1118 substitutions gathered from 21 basketball games. The analysed variables were coach-controlled (player and team’s personal fouls, player in and player out roles, player’s in and out minutes on-court and timeout situation); on-court (foul committed, free throws, 2- and 3-point field-goal effectiveness) and situational variables (scoreline, quality of opposition, game location and game quarter). The results showed positive scoring performances after the substitution for all the analyses. During the first quarter, there were significant effects for fouls committed, scoreline and game location after the substitution. The player’s out personal fouls, free-throw effectiveness, player in, minutes on-court player in, timeout situation and 3-point field-goal effectiveness were significant during the second quarter. The team’s personal fouls, game location, and scoreline were identified as important in the third quarter. The fourth quarter did not show significant effects on the independent variables. Current findings allow optimising coaches’ plans and team management of on-court and bench players throughout the game.

Examining Choking in Basketball: Effects of Game Outcome and Situational Variables during Last 5 Minutes and Overtimes

This study examined choking in basketball by identifying the effects of game outcome and situational variables during the last 5 min. and overtimes of close games. The sample consisted of two 5 min. segments (last 5 min. of the game, n = 147, of which 97 did not go into overtime; 5 min. of overtime, n = 50) drawn from 147 games from the Spanish Professional Basketball League (2007 to 2011). The following game-related statistics were gathered: 3- and 2-point field goals and free-throws (both successful and unsuccessful), offensive and defensive rebounds, assists, recovered balls, turnovers, blocks (both made and received), and fouls committed and received. The results suggested the need to account for the temporal structure and multi-skilled nature of the task when devising appropriate interventions.

Shaq is Not Alone: Free-Throws in the Final Moments of a Basketball Game

Abstract It has been previously observed that basketball free-throw (FT) shooting efficiency decreases towards the end of the game. The aim of the current study was to explore possible determinants for this distinctive pattern during close games (point differential of equal or under 2 points during the final minute of the game). A sample of shots attempted by 92 players in the Spanish professional basketball league (ACB) was collected. Several personal (age, experience, playing position and career FT percentage) and contextual (team ability, competition stage, game location, seconds remaining and score differential) variables were considered for the analysis of the data. The effects of the predictor variables on the players’ performance were analyzed according to two game contexts (FT attempted during the final minute or the last pair of FTs) using binomial logistic regression analysis. The results showed that during the final minute the only statistically significant variable was being in the center playing position (OR = 1.58), which decreased the FT shooting percentage compared to forwards and guards. In addition, the results during the last pair of FTs showed that the playing position of guards (OR = 1.70) and centers (OR = 2.22) was significant (a decrease in their FT percentage). Conversely, the score differential when tied (OR = -1.17) or losing (OR = -2.43) was significant, reflecting a lower probability of missing the shot. The results were interpreted and discussed from the viewpoints of crisis theory and the literature on choking in athletic performance.

ECCENTRIC EXERCISES COMBINED WITH ELECTRICAL STIMULATION IN THE TREATMENT OF JUMPER'S KNEE: A STUDY ON SIX HIGH LEVEL JUMPING ATHLETES

Introduction Treatment of patellar tendinopathy (PT)/Jumpers knee (JK) is known to be difficult, and there is no treatment of choice. This work analyses the development of a protocol using eccentric exercises and electrical stimulation, both using maximum tendon loading, to treat elite athletes suffering from Jumpers knee. Methods Six high level jumping athletes with chronic painful PT/JK completed a 6-month treatment/training programme using eccentric exercises and electrical stimulation. The protocol was done12 weeks in the winter pre-season and 10 weeks in the summer pre-season, for all together 36 months. Pain during patellar tendon loading activity was evaluated on a VAS, before the first session and then every 6 months. Results The VAS average fell significantly when the initial measurement is compared with those at 18, 24 and 48 months (p<0.01). There were no significant differences between the other comparisons, although they always improved when the protocol was followed and worsened following interruption of the latter (p>0.05). Discussion In a small group of high level jumping athletes with chronic painful PT/JK, eccentric exercises combined with electrical stimulation showed promising clinical results with significant pain reduction during tendon loading activity.

Players’ technical and physical performance profiles and game-to-game variation in NBA

Abstract The aim of this study was to (i) identify technical and physical performances of basketballers according to playing position in strong and weak teams, and (ii) describe variability in game-to-game performance according to game outcome, location, quality of teams and opposition. Performance-related variables of all the 699 matches of regular season 2015–2016 in the National Basketball Association were analysed. All the comparisons were performed using magnitude-based inferences. As could be expected, results showed that technical and physical performances differed between players of strong and weak teams. In technical aspect, forwards and centres from strong teams made more three-point field goals, but fewer two-point field goals, than their counterparts from weak teams. Interestingly, forwards and guards from strong teams covered shorter distances and lower speeds than their peers from weak teams. In addition, the three-point field goals made and attempted presented high variability. Game location generally had no significant impact on the variability of players’ performance. Guards exhibited relatively lower variability in technical and physical variables in comparison with players from other positions. Exploring the difference and variability of technical and physical performances of basketballers allows fine-tuning of practice and game plans in order to build up optimal winning strategies.