It is tempting to think that you can have Google forget everything it knows about your site and start over. However Google has a very long memory. There is no way to reset everything that Google knows about your site.
Penalties
One reason that Google doesn't allow you start over is that Google assesses penalties against sites. Allowing you to start over would erase those penalties. If your site has penalties, it is a much longer process to correct the problems and rebuild Google's trust than just starting over from scratch.
URLs
Google remembers all URLs that you have published on your site. Googlebot will continue to crawl those URLs forever, even if you have removed the content from those URLs. If you change all the content and URLs on your site, Googlebot will continue to get "404 Not Found" errors at the old URLs. You should either redirect each of those old URLs to the new URL of the same page, or configure your server to send "410 Gone" status for them.
XML Sitemaps
On a similar note, deleting your old sitemaps and submitting a new one won't change reset your SEO either.
- Google will continue to index pages even after your remove the sitemap or remove the pages from the sitemap
- A new sitemap will get Googlebot to crawl the new pages, but it won't help Google decide to index or rank them well
This article was written as part of a series about SEO myths.