I've managed to get a few Hubs up into the lower 80s before they have been published. What influences this is the same things as which effects a published Hub.
A high-quality topic, good written content, diversity of content (images, video, links, etc), good tags. The ranking algorithm looks at both published and unpublished Hubs. I always let unpublished Hubs stay that way for a few days after I finished making them specifically to see how they are doing and what can be improved. I'll then edit them to make them as strong as I can before I hit that publish button. They might spend a week being spruced up before they are shown to an audience.