dumb luck

He's been around quite a while now, too long for it to be just dumb luck.

The only reason he hadn't got killed in the last war was dumb luck.

Or worse, someone would probably find him through dumb luck.

He didn't, but once again dumb luck was working in his favor.

If you weren't dead yet, that was your dumb luck.

"But at least we'd have a chance for dumb luck to put us there!"

Just dumb luck we didn't camp on top of it in the dark!

If you were to be believed this was not good management but just dumb luck.

On the other hand, the people outside Florida are calling it dumb luck.

The fact that they weren't dead was probably mostly a result of dumb luck.