Hello. I have a site with approx 15,000 posts that I had built, some time ago, when I was Green... Google It does have page rank 1 but I want to dismantle the whole site and move the domain to a different server, then start over with new posts that are more closely related to the niche. If I do this and start putting posts on the site, that are tighter niche related, will this kill the seo with google? Also, is this done very often? Thanks for any feedback.
If you delete the articles and maintain only the domain page all the internal links will just vanish. This articles will also disappear from the index and the only thing that will remain will be the IBLs pointing to your home page. This is like breaking down your house... The house you want to live in - if I can make an analogy. It will be a disaster for your SEO. If you keep the articles and start writing new ones I don't see any problems. On the contrary if your new articles are somehow related to your old ones this is good news. You could also play a little with internal links in order to improve the rankings of the newer ones... You have a lot of options here.