If you have any doubts your run is impenetrable, then you need to close the coop up at night.
If you have a covered run and you've run hardware cloth around the perimeter several feet high, buried several inches of it into the ground, placed steal hog panels over the poultry mesh and hardware cloth, and run hot wire all around at two levels, and the gate can't be opened unless you want it to open, then you have a predator-proof run.
The above describes my run. Several years ago, I saw a bobcat walk around my original run and jump on each section, looking for a vulnerable spot to enter. He had found it earlier and killed one of my hens, and he kept coming back until I was finally able to squeeze off two direct hits with rubber shotgun rounds.
I've watched while a bear sauntered up to my run, drooling over my tasty chickens, and discover the peanut butter on the hot wire, get a swift and painful "message", and turn and run off, never to return.
I do sleep well at night, and I don't worry about my chickens when I need to be away. But it's required a lot of heart ache and hard work to get to this point.