In early FIFA World Cups, match balls were mostly provided by the hosts from local suppliers. Records indicate a variety of models being used within individual tournaments and even, on some occasions, individual games. Over time, FIFA took more control over the choice of ball used. Since 1970 Adidas have supplied official match balls for every tournament.
Update: While this ball was ruined in 3 days of use, the customer service team contacted me quickly and offered to send another product to try from this company. I thought this was very generous and warrants another try. With 3 kids now in soccer, I will update this review upon receipt of the next ball. (I added a star to the rating because they seem to want to stand by their company.)
If you are unsure of which size to get your child, I will recommend what size I think based off real-world use. The size 3 is good for any child until about first grade or second grade, which is when a child should move into a size 4. The size 4 should last until they get to middle school (around 6th or 7th grade), and then they would move into the adult official size 5.
Latex bladders are one of the best materials when it comes to ball construction. However, with latex bladders, air won’t last as long as butyl bladders and will need more attention for proper inflation. Butyl-blend bladders hold in the air much better, but they are harder and less receptive in play. Mid-priced balls will usually have a mix of butyl and rubber. https://www.youtube.com/watch?v=c1SVcjYY6TE