Racquet fit affects comfort, control, and injury risk. Compare grip sizes, head dimensions, weight distributions, and balance profiles through testing data.
A parent does not usually walk into the kids tennis shoes problem expecting it to be hard. The expectation is that you pick a size, pick a color the child tolerates, and pay.
You try a shoe on in the store. You walk a few laps of the carpet, do a couple of awkward little hops by the bench, and it feels right — snug at the heel, no pinch across the toes.