Thread: Dog getting out to far.

Hi guys,
So when i'm walking my 11 month old GSP down at the park she has a bit of a habit of getting out to far away from me. I'd preferably want her no more than 20 to 30 metres in front but she sometimes puts on the burners and ends up 100-150metres in front in the blink of an eye. When she has stopped I can whistle her back in and she will come but when she is at full stride it is hard to turn her. Is there something I can do to teach her that she has to stay closer to me (10-20 metres or so)? She is fine on a long rope so I can stop her but once its off she starts getting to far out.
What do I need to do to fix this? Teach a turn or stop command and if so how?
Any help appreciated.
Cheers.