Effects of variability of practice on self-efficacy and performance in basketball throwing

In this study, we analysed the effects of a variability of practice-based intervention on the perception of self-efficacy and performance in shooting a ball into the basket, in both a closed task (free throw shot) and open task (field shot during a game, hereinafter 'field shot'). A between-subject two-group unifactorial randomized block design with pre-intervention and post-intervention measurements was used. The intervention was carried out in a women's basketball team from l'Alqueria del Basket club in Valencia, of the high-level youth category (14-15 years). 6 players were assigned to the experimental group and each practiced shooting a ball into the basket from short and medium distance with one-handed technique for 15 sessions of 20 minutes, under perceptual, decisional and executive variability, while 3 players were assigned to the control group and practiced dribbling with changes of direction and rhythm under variability of practice conditions for the same amount of time. During the training, we manipulated the variables: distance to basket, ball size and weight, movements and positions before and during the throw, visual control of the throw, and physical overload of the players generated with additional weight or previous exercises. Wilcoxon and Chi-square techniques were used for the statistical treatment. The results revealed a worsening of the control group's self-efficacy, as well as a tendency for performance in the free-throw test to decrease. The experimental group improved its hit-miss percentage in free throw and 2 points field shots. In the discussion, we reflect on the impact of psychological factors or perceptual-motor skills on the results.