The key here is that 'new sites' are sandboxed or held off the main index, assuming NO INCOMING LINKS. Try adding a new site, without any incoming links to see how quickly it becomes listed, indexed, and cached, and stays in the index... that is the true test.

To insure a site is indexed, is dependent on lots of variables. One day you can have 300 pages indexed, and in an hour have 10 showing. The SERPS change constantly, and depending on which datacenter you are viewing the results from, that too can change almost in the blink of an eye.

Then there is also the supplemental index worry.

Factor in then the algo changes that seem to occur more often and confusion is a normal state of affairs when trying to work out your listings. SEO is not a science alone, but an art that is not easy to master, if at all.

As to the sandbox. There are lots of pros and cons, but bottom line is that it is always changing and can depend on penalties that exist, and where the links incoming are actually from, which includes relationship to the site being linked to.

my pennies worth :morning: