From the time I can remember until I left home at 18, we had two predator attacks. One was a fox that was taking one chicken every morning until Dad figured out its pattern and shot it. The other was a dog that killed several before it was also shot. We had lots of hawks and other ground based predators around, we occasionally saw them. We just didn’t lose a lot of chickens. Broody hens regularly hid nests and brought chicks out without predators killing them while they were on the nest. I consider this a general pattern that small farmers have used to raise chickens for thousands of years.
There is some luck involved but a lot of that is luck that you make yourself. We did not always have a dog around but usually we did. That dog was not a house dog but was left outside 24/7 where it could be a deterrent. It’s not that the dog went out of its way to protect the chickens, it just didn’t like other critters invading its territory. We did a lot of hunting, mainly rabbit and squirrel. If we saw a critter that was a danger we’d shoot it. Fence rows, pastureland, and fields were generally kept cleaned out so the critters did not have a lot of hiding places yet there were plenty of trees and bushes to provide shelter for the chickens. You need to look at the entire system, not a tiny portion of it.
Lots of critters like to eat chicken, but just because a hawk is flying over doesn’t mean it will take the first chicken it sees. But it can. I don’t know what motivates one critter to take a chicken while others just ignore them. Maybe some luck, maybe how plentiful other game is. From what I’ve seen it is quite possible you can go years without a predator attack, but it is also possible you can be wiped out at any time. With you only having a handful of chickens a loss is going to be more significant than someone with dozens of chickens running around.
Some people keep Llamas or donkeys to help keep the other farm animals safer from canines, dogs or coyotes. Some, not all but some, llamas or donkeys will attack canines. Some don’t. It’s not that they have bonded with the chickens or sheep and are trying to keep them safe, some just don’t like canines. But if they are grazing at the far end of the pasture when a coyote shows up, they won’t know it is there.
No one can give you any guarantees about any of this. You may be fine free ranging your chickens for years. But they are always at risk. You just don’t know.