There is a completely fenced yard... But, it's a 4' high picket, good fence, it's composite and Oz says he wouldn't jump it, but I am not believing him.
Look at TSC for their electrical fencing. Don't look at the ones for dogs, but price the ones for livestock. They are super easy to install and maintain.
If you have a dog that already pops a fence (runs and flys over) they aren't going to help. But if you have a dog that jumps on a fence (up and down) and then hooks and climbs, they work great.
I've always used one. I have a 4' chain link fence. NONE of my dogs will even attempt to stand on the fence. It gives a pretty good jolt, but it pulses so you don't have to worry about getting too much of a jolt.
You put the box in a place that you see everyday. There is a blinking yellow light and a 'click' sound as it pulses. Mine is in my porch. I see/hear it several times a day. If there is a problem with the fence, like something causing a break in the current) it'll either stop pulsing totally (no 'click' sound or blinking yellow light) or it'll be off beat.
I don't think an electric fence will stop a dog who has already learned to jump a fence. It might, but I wouldn't bet on it. But for me, as my dogs got older (and bigger) they tempt their fate and stick their nose on the hot wire. They only do it once.
My Lacy could easily sail over my fence. Hondo (even with his bum leg) could as well without much effort. But neither dog will get near the fence. Which makes me feel better because my Lacy gets it into his head that there is buried treasure in the yard.