EFFECT OF RULE MANIPULATION IN UNDER-10 COMPETITION ON RACKET TO RACKET TIME VARIABILITY

The aim of the study was to analyze the effect of modifying the net height (from 0.91 to 0.80 m) and court dimensions (from 23.77 x 8.23 m to 18 x 8.23 m) on the "average racket-to-racket time and its variability" in combination with different technical- tactical variables in simulated competition with under-10 players. A sample of 10,195 strokes (NM = 4902; VM = 5293) was used, extracted from 38 individual matches with 20 under-10 tennis players (age = 9.46 +/- 0.66 years, weekly tennis training = 2.90 +/- 1.07 h, tennis competition experience = 3.65 +/- 1.53 years). The variables analyzed were racket-to- racket time and variables related to game development (stroke type, stroke zone, rally duration). The players first competed in the Green Tournament under the Tennis 10s competition system with a net height of 0.91 m and court dimensions of 23.77 x 8.23 m (GV) currently in use, and one week later in a modified tournament with a non-linear approach (NM) in which the net height and court dimensions were reduced. The results showed that, overall, the average flight time is shorter in the NM (1.73 s) than in the GV (1.97 s). Additionally, there are no statistically significant differences in the variability of flight time between the NM and the GV (Mean Diff = 0.002 s). However, there are statistically significant differences in the variability of racket-to-racket time in the second serve (Mean Diff = 0.280 s) in favor of the NM. The results highlight that variability remains despite the differences in court dimensions; however, there are changes in the second serve, interpreted as exploratory behavior, facilitating this relevant aspect under the non-linear teaching-learning approach. The green stage of the Tennis 10s system should be modified to match the players' characteristics, thereby optimizing the teaching-learning processes.