I hope I'm not jinxing myself, but I have had chickens for about 5 years and I've not yet had a loss due to predation. I don't free range, but I do let them out for supervised foraging time, and I have a very large run and covered yard for them.
I have 19 chickens and 5 ducks. Their coop is 8x8, but the attached covered run is ~215 sq ft, and they have access to that 24/7. There's also a 20 sq ft duck house that opens onto the run, but the ducks prefer to sleep in the run. Divas...
The yard is surrounded by electric netting and covered with heavy duty aviary netting. The duck's pond is in there, too. The yard is 650 sq ft. They have access to that until nightfall when I lock them up in the run. We have pretty much every predator you can name here. When I do let them out on the property, I supervise closely to keep them away from the woods.
Now I used to live in a more suburban neighborhood. The only issue we had were hawks. I just made lots of areas for them to hide, but I am MUCH happier with the aviary netting we have now. If I were back in my old neighborhood, I'd probably rig up the netting somehow.
Truth be told, my neighbors free range their flock, and that's helped keep the predators away. Why work for a meal when you can get it easy? It's all about opportunity vs reward.