Pulling the dogs tail is all to do with balance, a good judge will be able to watch the "reaction" through the dogs spine. Dropping the dog on its front feet will allow to the judge to see two things, one the natural position of the dogs shoulders and hence the legs and feet- which in turn allows you to see the width of chest, rather than some people pulling their dogs front legs apart to make the chest appear wider, it also allows the judge to determine whether the dogs has a degree of flexibility, which all running dogs should have to avoid injury.
are what you say for show dogs or wo