yard = place for dog to potty and have FREE time , nothing more. Yards are not places where exercise generally happens. So keep in mind that yes it works for a lot of dogs but they are generally LOW to MEDIUM LOW energy levels and breeds where energy issues arent common or mixes that are very easy going.

"Blessed are the flexible for they shall not get bent out of shape"
"You can discipline and Discourage or you can Discipline and Encourage"
"Gentle in what you do , But firm in how you do it"