The easiest run I have found that is the best is premier electric fencing. It is lightweight and so easy to move.
You can make it in any shape you want and any area you want. The bottom is not electrified so it will lay on the ground nicely.
It keeps your chickens in and the predators out.
It even keeps my 2 dogs in!
Some chickens will jump it but if you clip their wings there is no problem
Here is the link to the website
And some links of videos
This netting really works I have had it for 1 year and have never lost a chicken to a predator since I got this netting
I have 70 chickens and only 2 rolls of this netting keeps them in plus to great pyrenees dogs
Cause if they touch it once they will never go near it again.
It doesn't shock chicks But keeps adult birds in.
Most of my chickens when they touch it they don't feel it because of all their feathers
Unless they are touching the fence for more than 10 seconds.
It really does work