Talk:Sport Balls/@comment-25636904-20150628105639/@comment-26143371-20150628122141

"You can now play catch with other Springfields! Throw a ball into their Springfield and they'll throw one back to you! Everyone can work together to win community prizes."

- In-game message.

This will appear when you start the quest Meet My Trophy Life Pt. 9 at the beginning of Act 2. And most likely the total amount of thrown Soccer balls will be counted towards the prizes

Also for me the first time getting community prizes...