Before we explain how search engines calculate Page Rank for your site or any other site for that matter, let’s complete the issue of How Search Engines Operate by explaining the last part, failure of spiders to crawl and index your pages.
We explained in How Search Engines Operate the way that search engines crawl and index your pages, but there is also the possibility that by your mistake spiders fail to crawl and index your pages, here are a few examples of why that happens. The most common reason why some of the pages on the website aren’t indexed is because the homepage has tons of hyperlinks, if you have over 100 links going from your homepage be sure that half of them won’t be indexed.
Unless your site has a bunch of external links pointing to your homepage all of the pages that are buried under 3 links/clicks from your home page won’t be indexed.
Of course all pages that require a login, pages accessible only via search box and pages that redirect before providing content will not be indexed by search engines. You need to place the most important links of all the pages that you want to have index on your homepage, but you can’t overdo it, as we said, too much links on one page will also have a negative effect.
Calculating Page Rank
There are several things that search engines use, in this case Google, to calculate Page Rank. Now mathematically speaking you can find the explanations all over the internet, and they will just confuse you, I mean Google’s algorithm for calculating page rank is out of this world, but hey, if there are people that say they understand it good for them. I am not an expert on algorithms, but I have been long enough in this business to know the basics behind the algorithm, so here is the basic concept of how Google calculates page rank.
The easiest way to understand is to look at every link coming from another site to your site as a vote cast by that website. But this is not democracy, in essence the more votes you have the more important your site is, but not all votes are equal. One vote may be worth 100 of others, depending on the value of that site or page rank from which the link comes.
Calculation of Page Rank is done by taking a part of value of each site and its PR pointing to your site. Although that is just part of the equation, Google uses your own back links and relevancy of your content to determine the page rank. But for now we will explain how it calculates page rank based on links coming from other sites.
The idea behind Google’s algorithm is that every link coming from some other site carries and brings a certain PR value to your website. So that is more than enough to figure out that higher ranked sites bring more juice to your site. But If a PR8 site pointing to your site has 50 links pointing to other sites from the same page, it will bring less value to your site than a PR6 website pointing to your site with only 3 links from that page to other websites. You see where we’re getting at, every page passes only 85% of its Page Rank to other sites, but that is divided by the number of links going from that page. So you should choose who you link to and who links to you, 1000 links from a PR1 site may be worth as much as 1 link from a PR5, or it could be the other way around considering how many outbound links the site has.
You also have to understand that not all PR values are the same; each PR is a set of values and not a single number. One website that has a PR4 may actually be on the lower boundary to becoming PR3 or it may be on the upper boundary to becoming PR5. All in all if you want to up your PR the first thing you need to do is get links back to your site, a few links from high PR sites might do the trick or you can try gathering thousands of low PR links. Remember one thing before we continue down the Calculating Page Rank, PR is not the only thing that determines where you place in search engines and how much traffic you get, but it is an important part of the equation.
About The Author
Zarko Zivkovic is the founder and CEO of Practical SEO and also a passionate blogger. All of his free time he dedicates to his Practical SEO blog and giving free advice as well as participating in the blogging community.
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