The aims of this research were to (a) demonstrate how a principled approach using anthropometric measures of the hand can be used to identify the most appropriate basketball size for junior basketball players and (b) examine participants’ preferences in relation to the use of different sized basketballs after gameplay. The hand spans and hand lengths of junior and senior male basketball players were measured and used to create hand size-to-ball-size ratios. Junior male basketball players also competed in 3 vs 3 half-court games using size 3, 4, 5, and 6 basketballs. Using the hand size-to-ball-size ratio as a means of scaling equipment for junior basketball players revealed that the most appropriate ball for 11-year-old boys is size 3 or 4, however, the junior players preferred using the larger basketballs (size 5 and 6) during gameplay. Anthropometric measures of the hand can be used by sports administrators and coaches as a principled means to scale sports equipment for juniors. Given that the preferred ball size appears to be influenced by the prior experiences of each child, it may be important for scaled equipment to be introduced during the initial stages of motor learning.