Leash Tie Out?

Does anyone use a leash tie-out type thing in the yard when playing with their dog? I don't have a fenced in yard and am probably getting a dog sooner than I am getting the yard fenced. The dog I am probably going to foster from the shelter likes to play fetch so I was hoping to come up with a way to play fetch with her in the yard but have her still be "on leash" so she doesn't run off, obviously. The leashes i have are 6 ft leashes so I was wondering if anyone had any recommendations for leash tie-outs or long leashes or any experience in general with playing with a dog on leash in the backyard? Thanks!