There's a biggish site (3,000+ pages of evergreen content) that needs reorganization. The problem is that the main categories have dozens and dozens of articles in them, making those categories have very long index pages.
A lot of the pages on the site currently rank well in search engines, and the challenge is to somehow make the site navigation more intuitive for newcomers without losing search engine rankings for some of the pretty deeply buried, older (still valuable) content.
One possible fix is to break those main categories into subcategories and link to the subcategories from the main category page. Then the links to the articles that are now on the category page would get moved to the subcategory page. The article URLs themselves would not change.. the only thing that would change would be the page that points to them.
Does anyone have any thoughts - or better yet experience - about how that kind of change might affect search rankings?