Unable to answer "What sport is played here?" – Sport Pitch – osm.org/way/622300175 via StreetComplete 58.2:

That is someone's back yard

No curb-cut here

via StreetComplete 58.2

Attached photo(s):
https://westnordost.de/p/225946.jpg

In context of overlay "Buildings" – osm.org/way/777854362 via StreetComplete 58.2:

This house is not here anymore

Attached photo(s):
https://westnordost.de/p/225942.jpg