Well, maybe you think you have tried everything humanly possible to keep your dog inside your fence!
You've filled holes where they have tried to dig their way out, used boards to cover the holes or placed some other thing in front of the hole thinking it would solve the problem. Maybe you have a climber that somehow manages to get over the top and escapes that way. When you have a dog that is determined to get out one way or another, it can drive you nuts!
If your back yard fence is looking like a war zone with patches here and patches there, maybe it's just time to find a new approach. If a chain link or wooden plank fence isn't working, then perhaps an invisible fence might be what you need. For some dogs, it is the only thing that works. They can't climb over it and they can't dig under it!
Invisible fences are fast becoming a logical replacement for older fences when people have pets they want to keep in their own yard. You can look at websites like doggybakery.org to find really great options in fence solutions for your pet. Invisible fencing is only one of several options just in case you had really rather keep the fence you have, but would like to make it more escape proof. Other options are more affordable yet still very effective. You can find ways to keep your dog from climbing over or digging under a fence.