Effects of manipulating the number of targets in U9, U11, U15 and U17 futsal players' tactical behaviour.

This study identified how the manipulation in the number of goal targets affects the tactical behaviour of players from different age groups (U9, U11, U15 and U17). Forty youth futsal players performed two small-sided games based on Gk + 4vs4 + Gk situation with one regular and two small targets. TACTO software was used to capture players and ball displacements. The following variables were computed and presented as absolute values, coefficient of variation and regularity (approximate entropy): (i) distance from each player to the team centre (DtC); (ii) distance from each player to the ball (DtB); (iii) distance between team centres (DbTC); and (iv) distance from team centre to the ball (DCtB). The team dispersion increased with two goal targets (mainly the DbTC, U9 and U17, large effects; U11 and U15, very large effects). Also, the use of two goal targets condition increased the variability in the DbTC (U9, small effects; U11 and U15 moderate effects; U17, very large effects) and DCtB (U9 and U17 moderate effects and U11 and U15 small effects). Overall, the approximate entropy values showed higher regularity in the condition with two targets. All age groups were sensitive to the manipulation of goal targets, however, the U9 were the most sensitive to the changes, as seen by the dispersion of players in the field. Thus, coaches can use one target to promote movement irregularity of players and two targets to increase the team dispersion, mainly in younger age groups that tend to be agglomerated around the ball.