It is important to keep in mind why we ask something of a horse and know when we have achieved our goal, in order to know when to quit asking. On its own, ground work has no purpose. There are no Olympic or World Cup competitions in ground work.
I explained that the purpose of the groundwork was to better prepare a horse to be ridden. Everything we do should be connected to developing a better riding horse.
Sometimes I hold the lead rope very short - under the chin, at the point it attaches to the halter. Other times my hold gives the horse the full length of the rope to search for an idea.