Using 'Hide this page from Search Engines'
Hello,
If I have existing pages I know longer want to be accessible by google I have a few options.
1) Implement 301 redirects from old URL to new ones.
2) Select the 'hide page from search engines' in properties.
3) Remove page from Sitemap - but leave published.
If I do not put in 301 redirects and just select tick box to hide from search engines and sitemap, will this create 404 errors or will Google simply start to ignore pages and stop listing in SERPs?
Thanks