Woosh....he's gone!

First off, the website is great! It has incredible resources for such a labor intensive breed!

OK, my Jack Russell is approximately 1 year old (I don't know for sure, I got him at the pound). I have taken him to basic obedience class which he passed with flying colors. I will make no mention of how many hours spent to get him to pass, that is another story. My question is if you have any suggestions for the "run-away". He lives to roam a large secured yard accessible through a dog door yet retains the desire to check out the other side of the fence at any opportunity. At first notice the gate or front door is, or will be open he is ready to run. And run he does, I am 6'3" and my stride can't come close to this 12" mutt (term of endearment of course). He runs away and checks out as much of the neighborhood as he can before I finally snatch him up. When leashed he is great at recalls, even with the lure of freedom in the front, unfenced yard. It is only when an unsuspecting person opens the door that he takes advantage of the situation. This is obviously the behavior that brought this jack into my life in the first place, however, I would rather not have him go through it again. I have tried tying him up to a string and opening the door wide open. He ran once, discovered he was attached, and quickly realized the repercussions. Unfortunately this dog has figured out the difference between when I attach this tiny nylon cord and when he can actually bolt successfully.

I would appreciate any suggestions you may have. This dog has the physical potential to become the Carl Lewis of Jack Russell's, if I can only harness the energy in one controlled direction. Hence, the struggle of all Jack Russells.

Thanks again, and good luck everyone with such a great breed!