How Google Counts BackLinks?

How google counts backlinks? and when its crawler counts? Different SEO experts have their different views and no one exactly know that how really google algorithm works. Experts have thier own reviews and experiences about website back links and the authority. But this really difficult to analyze that how search engines specially google counts back links. You may find many good PR sites with many back links in yahoo but when you will search in google with link:www.domain.com , you may not found much back links even some time 0 back links.

Even people doing seo from last decades still don’t have exact pattern about how google counts back links and if counts how much power it can transfer to site. This question is still to find out that what’s exact pattern and back links google search crawler counts and give authority to the website. Question or myth still unsolved!!!!