Relevance (not relevancy) score is the most basic term of SEO. But I'm not surprised to find out that so many practicing SEO technicians have never heard of it and cannot therefore imagine the hidden reality behind what the eyes can see.

What makes it easy in one case (search query) to advance from # 11 to # 10 in Google and practically impossible to advance from # 11 to # 10 in another case? The invisible relevance score gap! It might be one point in one case and ten thousand points in the other, though the gap in rankings is one number for both cases.

Moreover, the pages shown above yours may raise their relevance scores at a rate that is higher than the rate at which you raise the relevance score of your page, and you'll never catch up despite all the work invested. All rankings stay the same but the client is told stories about a recent algorithm shift.