The first playground that you register (or newly created) during account creation will be your Homeground. Typically Homeground would also mean that this is a user’s primary (i.e. favourite) Playground. By identifying your Homeground, you will locate your favourite Playground faster, especially for users with many Playgrounds.
When a new Team sport group is formed, the group’s Playground(s) will be registered from each member’s Homeground.