Certain high google ranking websites do not have desired query.Even then these appear again & again.and we consider that google lists quality sites.
What is the strategy behind google sites ranking? what google loves about sites that it shows up in each repeated search.
Read and re-read and check back for updates on the google webmaster guidelines
They tell exactly what they are looking for.
I don’t think the main criteria is that the site is a quality site, but that the site is considered most relevant to the search terms. - If you search for a low quality site you can find them 
What is the complete strategy? Only Google knows.
All else is speculation and conjecture.