playing fetch ball with small dog and still be on leash

It depends how persnickety they are. A fifty foot clothesline from the dollar store would provide ample room for a game of fetch with a small dog, if the space is open and the terrain relatively smooth. Most parks say six feet for the leash, but you can ask if they'd be okay with longer for a daily exercise session, provided you find someplace appropriate.

Some parks also have fenced dog play areas that can be great for a game of fetch.