> why aren't we getting thousands of hits for "from what it is to a"? Because Google isn't an exact search engine. Each of the terms in the phrase above appear

> why aren't we getting thousands of hits for "from what it is to a"? Because Google isn't an exact search engine. Each of the terms in the phrase above appears on billions of pages. My guess is that for common terms Google doesn't store all postings in its inverted index but truncates the posting lists after a couple of million entries.