Page Rank Calculation

[bobmutch]

everyone: Check out my new article Page Rank Calculation (http://www.seocompany.ca/pagerank/page-rank-calculation.html) based on Bob Wakfer's PageRank Calculation Chart (http://www.compar.com/infopool/articles/PR-calculation.html#page-rank-calculation-chart) where I address the question "how many links do I need to get a page rank of 5 or 6?" and make 4 simple rules.

Rule 1: 18 PRx links to get PRx (i.e. 18 PR5 links to get a PR5).
Rule 2: 3.339 PRx links to get PR(x-1) (i.e. 3.339 PR6 links to get a PR5).
Rule 3: 101 PRx links to get PR(x+1) (i.e. 101 PR5 links to get a PR6).

As Walfer's calculations are based on links having 50 Total Outbound Links (TOL) there were some simple rules need to revalue links.

Rule 4a: Revaluing link to PRx: 6.25(PRx/TOL) PRx (i.e. PR8 130TOL: 0.385 PR8)
Rule 4b: Revaluing link to PR(x-1): 34.375(PRx/TOL) PR(x-1) (i.e. PR8 130TOL: 2.1 PR7)
Rule 4c: Revaluing link to PR(x-2): 187.5(PRx/TOL) PR(x-2) (i.e. PR8 130TOL: 11.5 PR6)
Rule 4d: Revaluing link to PR(x-3): 1037.5(PRx/TOL) PR(x-3) (i.e. PR8 130TOL: 63 PR5)

The article is a pretty easy read and explains how I came up with the rules.

[etreus]

Very interesting articles, thank you.

They have also explained something I have been worried for the last weeks since the last BL update. Also have gotten no answers in the two forums I visit.

That is that Google does not show all backlink information:

Quote from Bob Wakfer:

"The one trick to this link search is that Google does not display all backlinks. At one time it was thought that they only listed pages with a value of PR4 or greater. Today however, you will find backlinks reported from pages of lower PR values. So, at best, Google's backlink search seems to present some sample of pages linking to the site. Suffice it to say that this search is not a reliable measure of all IBLs to a page."

Thanks for clarifying this!

[hurricane_sh]

bobmutch, your logo is very cool

[bobmutch]

hurricane sh: hehehe thanks, made it myself if I may say so :)
etreus: Just in case I didn't explain myself in the post very well Bob Wakfer's PageRank Calculation Chart article is written by Bob Wakfer's and the Page Rank Calculation article is written by me bobmutch.
On the inbound links end of things go to Yahoo and do a "domainlink:www.example.com" and that will give you your inbound links. If you want to you can do a "domainlink:www.example.com -inurl:www.example.com" to exclude your internal links.

[anthonycea]

Bob who?

Bob you better get your posts corrected, you have Bob's last name mis-spelled in your posts, wouldn't want "The Donald" mad at you, would you Bob?

You could hear the words "YOUR FIRED" real soon man. :mad:

[bobmutch]

anthonycea: Well if I spell the name wrong he will have something to flame me on and not be so hard on the article :)

[anthonycea]

Don't count on it, the Compar Mafia will get you one way or another, once your in, there is only one way out :eek:

[schlottke]

Anthony- youre out of control.. lol

[john_loch]

Oi Bobmutch,

You really should get Bobs name correct - at your site anyway. It's just a common courtesy thing, when you're featuring their works.

You've only misspelt it once, but hey - I'm pedantic !!

Cheers for the article :)

[bobmutch]

john loch: anthonycea pointed that out about 6 hours ago and I quickly corrected the spelling. I just double checked this thread and my article page and as far as I can see the spelling is corrected. You may want to try doing a refresh if the spelling of Bob Wakfer is still incorrect.
"If I approached you to reproduce your work at one of my sites (which I may btw)." Really, well I would be honoured. Email me at bob@bobmutch.com and lets work something out.
I would also be open to suggestions for articles. The way I get some of my ideas for articles is by answering questions on the different forums I am subscribed to and then publishing an article on that subject.
Check out Scrub Warehouse (http://www.seo-guy.com/forum/thread2253.html) for a bit of fun over at SEO Guy Forum.

[john_loch]

I edited my post above..

Cheers, JL.

[anthonycea]

Bob we are only hard on you because we love you, remember youa famialy nowa, there is only one way out of the Compar Mafia.

Concrete boots, you sleepa wit du fisha, youa knowa wata meena bon?

Be cool G........ :D

[compar]

Bob we are only hard on you because we love you, remember youa famialy nowa, there is only one way out of the Compar Mafia.

Concrete boots, you sleepa wit du fisha, youa knowa wata meena bon?

Be cool G........ :D
Anthony, I think you are on more than Jack Daniels tonight. :)

[anthonycea]

Sorry Boss, I won't give out no more family secrets, just breaking in the new kid, all business from here on in boss :cool:

[ResaleBroker]

Thanks for the article. It seems pretty straight forward. Based on your formula the PR for two of my sites should be different. I have listed their information below. Any ideas on why site #1 is so low and site #2 is so high?

Site #1 Current PR = 1 [resalebroker.com]
Actual BackLink Counts:
PR 0 26
PR 1 3
PR 2 4
PR 3 2
PR 4 3
PR 5 5

Site #2 Current PR = 5 [ezliving.com]
Actual BackLink Counts
PR 0 2
PR 1 1
PR 2 3
PR 3 2
PR 4 1
PR 5 3

Thanks!

[bobmutch]

ResaleBroker: Well thats kind of interesting but with 5 - PR5 links and your site only at PR1 I would have to ask when the you got the links? It has been 66 days since we have had a PR update but we have had a backlink update during that time if I remember correctly. So it would be my guess that the backlinks are new so Google shows them, but your new PR will not show on the toolbar until the next PR update.

[ResaleBroker]

How did I know you were going to say that? :p

What about the second sight though? By my calculations it shouldn't have a PR5.

[Nitin M]

If only Pagerank were this simple. Unfortunately, it isn't.

The link structure of the entire site of the page you are attempting to estimate the PR of has too much bearing on the PR to be able to guestimate the page's PR based purely on information about the incoming links.

Take a thorough read of this article and study the example and you will see understand why the strucuture of your site has such a huge impact on the PR of any page in the site:

http://www.iprcom.com/papers/pagerank/index.html

[a389951l]

Thanks for posting that article!

[compar]

I have learned a couple of things since I wrote the original PageRank Calculation (http://http://www.compar.com/infopool/articles/PR-calculation.html) article.

But before I tell you about those things I'd asked that you read the original article carefully. I clearly point out in the article that both internal and external links are used by Google in calculating PR. So Virginia Realtors' comment about it not being that simple is wrong. It is that simple.

It is a straight forward mathematical calculation based on all the PR values of all the pages that a page recieves links from. Nothing more and nothing less. If you think about this statement carefully you will realize it even covers the case of "PR leak".

Now what addition information I have learned.

To build a chart like this you are forced to make some assumptions. The major assumption built into my chart is that all the pages have an average of 50 outbound links. I was never very happy with that assumption, but it was based on the fact that Google recommends not having more than 100 links per page and so fifty seemed like a half way cut off point.

Since the chart was published Rustybrick has given us a new and very useful tool for analyzing the linking structure of pages. http://www.rustybrick.com/link_analysis.php This tool will tell you the number of backlinks a page has from pages of each PR value.

I took the results from this tools and plugged them into my chart. I found the correlation was good but not perfect. I started to adjust the "50 links per page assumption" and I found that when I changed this assumption to 40 links per page I got a 100% correlation with the actual results Rustybrick was reporting -- at least for the approximately 10 different pages that I test with.

So I am going to revise my article to reflect this. In the meantime if you would like a copy of the original Excel spreadsheet with the assumption changed to 40 you can download (ftp://ftp.compar.com/pub/PR.xls) it here. And if you would like a copy modified so that you can enter Rustybricks results and then play "what ifs" by looking at the impact of adding addition links you can download (ftp://ftp.compar.com/pub/PR-test&forecast.xls) that chart here.

Remember also, as has already been said, that it is very hard to do tests or forecasts on new pages or recent links because Google has not done a PR update in a long time.

[bobmutch]

ResaleBroker: Well Google doesn't show all the backlinks you have. You need to go to Yahoo and do a linkdomain:www*evliving*com -inurl:www*evliving*com -inurl:evliving*com which gives you all your inbound links minus the internal links from your other 2 sites www*evliving*com and evliving.com . Yahoo reports 327 links and they seem to all have high page rank. 5,5,3,5,3,5,4,2,4,4 just in the first 10.
Replace the asterisks with periods.

[Nitin M]

But before I tell you about those things I'd asked that you read the original article carefully. I clearly point out in the article that both internal and external links are used by Google in calculating PR. So Virginia Realtors' comment about it not being that simple is wrong. It is that simple.

Sorry Compar, but your article is an oversimplification of the Pagerank algorithm.

I have studied your article in detail and it omits a huge component of calculating Pagerank and that is that the algorithm must be iterated over many times before you reach a stable state of Pagerank values.

I'll post again the link that I believe most clearly summarizes how Pagerank is calculated and if you study the article you will realize that a site's internal link strucure has a significant impact on the Pagerank of any page within the site.

http://www.iprcom.com/papers/pagerank/index.html

By only looking at incoming links to a page you can only measure the amount of Pagerank that is being sent to the page; not the amount of Pagerank that will be applied to the page after iterating over its own link structure.

[compar]

you will realize that a site's internal link strucure has a significant impact on the Pagerank of any page within the site.
Where in my article did I say otherwise? PR is the sum of all the pages that link to your page. If in turn the page in question links to pages that link back -- internal links and link structure -- then this will effect the final PR of the page. This is entirely consistent with my article. I never said or suggest otherwise.

So one more time you are wrong. You haven't absorbed the entire message of my article. It is simple. If a page has a large number of outbound links, the amount of PR it passes is reduced. Therefore the PR passed to internal pages is reduced and as a result the PR that is passed back is reduced. There is nothing in my article that is inconsistent with that.

Before you criticize my article try and understand it.

[bobmutch]

Virginia Realtors: You address two issues. 1) That the algorithm must be iterated over many times before a stable state of PR is gotten, (This is a commonly known fact to any one that knows anything about the ragerank algorithm) and 2) Only looking at incoming links to the page you can only measure the amount of PR being send to the page, not the amount of PR that a page will have after being iterated over many time in its own link structure.

Compar states above that his article is not inconsistent with your comments in point #2, and having read it over one more time I would agree. He didn't address those issues, but this article is not inconsistent with those issues. His chart shows the PR value of inbound links and didn't discuss the effects of outbound links or the structure of internal links.

I would have to say that again like the required alogorithm iterateds to get a stable state, that any one that knows anything about ragerank is fully aware of the fact that outbound links and internal link structure effect a pages PR and not just the inbound links. So considering the depth of understanding the article displays the writer has, and how elementary that issue is (that outbound link and internet structure effects PR), to think that the writer was/is not aware that outbound links and the structure of the internet links effects the PR after writing an article like that, tells me that you many not be relizing how elementary those issues are.

As for your your #1 issue I didn't see where Compar's article or calculation notes how many times the algorithm is being iterated (it is generally accepted that 20 to 40 tmes is enought for simple calculations before they stablizes). Also Compar didn't address that issue in his return post to you.
Compar: Could you inform us the number of times the algorithm was iterated in your table calculations.

[compar]

[B]Compar: Could you inform us the number of times the algorithm was iterated in your table calculations.
Nobody know how many time the calculation is done, or how many iterations Google makes before declaring a PR value for a page. And my chart doesn't try to determine that.

What I present is the probably value, and range of values, for various PRs after all then iterations are done. Certainly the internal structure of a web site will impinge on the final PR of each page. However a detailed analysis of internal linking is another subject. And as you suggest I did not attempt to cover it. That said however, the values that I present in the chart are still valid. The value of a page may be higher or lower due to internal linking, but my ranges are still valid no matter how they are arrived at.

[ResaleBroker]

ResaleBroker: Well Google doesn't show all the backlinks you have. You need to go to Yahoo and do a linkdomain:www*evliving*com -inurl:www*evliving*com -inurl:evliving*com which gives you all your inbound links minus the internal links from your other 2 sites www*evliving*com and evliving.com . Yahoo reports 327 links and they seem to all have high page rank. 5,5,3,5,3,5,4,2,4,4 just in the first 10.
Replace the asterisks with periods.

That's pretty handy. Thank You!

[nelsonhomer]

what are ?

PRx?
TOL?

Nelson Homer
www.guide-for-beginners.com
www.ehanapbahay.com
www.pinoyoutsource.com

[ZanderXML]

Google recommends not having more than 100 links per page and so fifty seemed like a half way cut off point.


Where I can see this recommendations? Thanks!

[Cricket]

Where I can see this recommendations? Thanks!
Google Information for Webmasters (http://www.google.com/webmasters/guidelines.html)

Design and Content Guidelines

"Offer a site map to your users with links that point to the important parts of your site. If the site map is larger than 100 or so links, you may want to break the site map into separate pages."

"Keep the links on a given page to a reasonable number (fewer than 100)"

[Nitin M]

Where in my article did I say otherwise?
As I said in my post, you're article is misleading because it leaves out a crucial element of the Pagerank algo which is that it must be iterated over many times to reach a stable state.

Because of this omission, in my opinion. your article and especially your Pagerank Calculation Chart is misleading.

By its omission, it gives the impression that by simply looking at the static PR values of the pages with links to your page, you can determine the PR of your page. If you understand that the equation must be iterated over many times, then you understand this is not the case.

From your article:

The chart that follows shows the range for each PR value. It also shows how much PR value or PR points a page with 50 outbound links will pass depending on of its own PR rank. From this I have calculated the number of links required from each value of PageRank necessary for a page to attain a desired page rank.
You can argue that you never said NOT to iterate over the equation many times, but you do not even include a discussion of it.

Your chart showing number of links from a page with a certain PR to achieve a PR value leads a novice to believe if they get these incoming links from another site, they should achieve the PR you have listed. The reality is, it will also depend on the link structure of their own site.

So considering the depth of understanding the article displays the writer has, and how elementary that issue is (that outbound link and internet structure effects PR), to think that the writer was/is not aware that outbound links and the structure of the internet links effects the PR after writing an article like that, tells me that you many not be relizing how elementary those issues are.
I don't think I attacked compar's knowledge of the Pagerank algorithm. What I am saying is that his article has a serious omission and by this omission presents an overly simplified view of Pagerank that could mislead people not already intimately familiar with the algo. He has posted his article many times to help people understand Pagerank. I think the article I posted gives a much better explanation of Pagerank.

While you seem to believe the iteration is "elementary" - I would argue that most people just starting to understand Pagerank do not understand it.

[bobmutch]

ResaleBroker: Yes it works very well if Yahoo has your site indexed.
nelsonhomer: TOL is is noted on the first page of this thread, "Total Outbound Links (TOL)." Total outbound links is the total number of links from a page that are outbound vss inbound (links that are made to a page.) In PRx the "PR" is a short form for Page Rank and the "x" is between 0-10. PR(x-1) just mean what ever value is asigned to X minus 1 etc.
compar: Yes I kind of got to thinking and realized that later that you probley didn't have to iterate the algorithm as you were just providing a statement of relationships.
I agree we don't know how many times the calculation is done by Google on the internet. We do know that for simple calculations the numbers settle down after about 20 to 40 interates. If we take 0.15 + 0.85(x) and put in any number from 0 to 20 it will move to ~1 within 40 interates. But yes the internet is a different story.

[compar]

While you seem to believe the iteration is "elementary" - I would argue that most people just starting to understand Pagerank do not understand it.
I agree most people do not know about the iterations required to determine PR. But it has nothing to do with my chart. PR is not declared until after all the iterations are run. There is no PR before that. My chart shows the relationship when PR is reported, and after all the iteration are run. It then represents the probable number and value of all the pages that have been included in the calculation, which has resulted from many iterations.

You can't have PR without iterations. And it doesn't matter if anyone knows about iterations or not. When the PR is calculated my chart shows the probable relationships and values between all the pages. I have tested this against actual results and as I've said already if I change the average links per page assumption to 40 I get a very strong correlation with the real life pages that I have tested. If the chart correlates with real life pages I fail to see how it can be too simplistic.

[Nitin M]

And it doesn't matter if anyone knows about iterations or not.
We'll have to agree to disagree on that point.

Many times people will ask questions like: "If I get a link to my homepage from a page that is PR7 and has 50 links on it ... what will the PR of my page be?"

Using your data, the median PR passed would be 8,291. Your article leaves the reader with the impression that is all there is to it. Based on that link (let's assume it is the ONLY incoming link to keep things simple), the PR of the page being linked to is 8,291 --- a PR5 using your tables.

BUT - depending on how the site is setup, the actual PR retained by that page could be as low as 8,291 * .15 = 1,243 --- a low PR4 using your tables.

Unless you understand that the PR calculation is recursive, you will miss this. For very large sites where the site itself generates significant PR, this point becomes even more signifcant.

Perhaps your explanation/article is the best way to introduce people to PR ... my $.02 ... it would be a more complete article if you make some mention of the fact the PR calculation is recursive and that internal site structure will have a large impact on the retained PR of the page being linked to.

Again - I don't mean to attack you personally... just saying I think the article is misleading in this area.

[bobmutch]

Virginia Realtors: I didn't mean to infer you were attacking compar's knowledge, but it seems clear that you are infering that compar doesn't understand how internal structure effects page rank and the important of algorithm interates by your first 2 posts:

"Take a thorough read of this article and study the example and you will see understand why the strucuture of your site has such a huge impact on the PR."

"I'll post again the link that I believe most clearly summarizes how Pagerank is calculated and if you study the article you will realize that a site's internal link strucure has a significant impact on the Pagerank of any page within the site."

My comments did point out that to someone that is in the know on pagerank these two issues are elementary, and to say to some one that comes up with a good article like compar does, that they need to read up on algorithm interates and that outbound links and internal linking structure effects PR, could be taken as an insult to their intelligence. I am sure you didn't mean it that. Further I noted that the fact you don't seem to relize how elementary these two issues are to those that are in the know, could be seen as implying that you many not be as far along as you think you are. I trust that is not the case, and I certianly don't mean that as an attack, just an observation.

Again the two issues are elementary to those who know what they are talking about when it comes to pagerank, I was not refering to those issues being elementary to those just starting to understand pagerank.
As compar has noted he doen't deal with those 2 factures in his article. He does touch on internal link structure in his following article PageRank & How to Get It (http://www.compar.com/infopool/articles/PR-How-To.html) but doesn't go into algorithm interates in either of them.
Personally I am not sure you have to get the formula out and try to get people to undersand all that right off the bat. The formula can be overwelming for those that are just being introduced to pagerank. Yes there is a place to go over the formula, and yes understanding the formula is important as is understanding algorithm interates and how internal linking structure effects PR. I think what compar's article does is, without getting into forumals tells a person in general, hey, you need 18 PR5 coming into a page to get a PR5.

I do agree that perhaps his article could be improved by noting that the chart doesn't take into consideration internal link structure or outbound links. You many want to suggest that to compar instead of making posts that seem to imply he is lacking elementary understanding on the subject of his article. I have already made changes in my Page Rank Calculation (http://www.seocompany.ca/pagerank/page-rank-calculation.html) article in responce to your comments. I took your comments as helpful, made changes, and have overlooked the way you brought them out.

I agree that going into the pagerank formula will help some one that can grasp it, and is ready for that, but for some one that don't know anything about pagerank and is just wanting to get a rough idea of what kind of links they need to get a certian PR, I think compar's article is helpful.

[anthonycea]

For many years Brain Surgeons would not make changes in surgery techniques thinking that entry from the top of the skull was too much of a risk for the patient. That was until one surgeon proved that it could produce good results without danger to the patient. When he proved this, all of the surgeons accepted the practice themselves.

If you have a valid point Bob is wise enough to accept it and improve his study also. I am sure he welcomes the new information if it is valid.

[bobmutch]

anthonycea: hehehehe, er which Bob.

[anthonycea]

I do not see either of you standing still, if you can improve yourself or your content, you or Compar will both do that :cool:

Bill Gates was wrong about the internet, but he got on board when he found out that he was missing the boat.

So, Bob and Bob are smart enough that when they find a flaw in the theory published, it will be corrected or adjusted also.

Hey Bob might even give credit to the guy that helped him find the flaw, Compar is a good guy after it is all said and done.

Even if some of us try to make him look like a bad guy in jest :D

[Nitin M]

Can't we all just be friends? ;)

I certainly didn't mean to offend anyone by any of my comments and I apologize if my approach/langauage isn't as sensitive as it should be. I will say what I believe to be obvious ... anyone that takes the time to put together tools/articles or simply to respond to posts here to help others is obviously contributing positively to the community and should be applauded... so cheers to bobmultch and to compar for taking the time.

My feedback for you both is to consider that a wide variety of people with very varied degrees of insight into Pagerank will be accessing your resources. I think if you are going to present a simplified view of Pagerank it should be with at least a mention or reference to the facets that have been omitted.

[bobmutch]

compar: Lets say I got 18 inbound PR5's links of medium value to the home page on a 10 page site that has a fully meshed internal link structure. Your chart shows that 18 PR5 Links to a "page" will give it PR5.
Is your chart take into consideration the PR that home page will pass on to the other 9 pages and how that will effect the end PR of the home page. Or is your chart just take into consideration 18 Link of PR to one page and the effect it will have on that one page with out considering whether that page is linked to other pages or not.
If your chart is only taking into consideration one page by its self with 18 inbound links then the person trying to apply this to there site must take into consideration how much of the PR will be transfered to the other pages that are in the site for the chart values to be meaningful.
If this is the case I think the chart would be more meanful if it would note the value of the receiving page in for a 10 page site with a fully meshed internal linking structure and no outbound links.
While you can't have a chart that would be adaptable to every sitituation it would be best to pick a site structure that is pretty common like a 10 page fully meshed site.
I am not saying your calculations are off. I am just questioning to what can they be applied to.

[bobmutch]

Virginia Resultors: Well you didn't offend me all it did was make me think. Take a peek at the 4th paragraph I added to my article and let me know if that made things a bit clearer. If you have further suggests to make it clearly I am very open to them. You may even want to suggest how compar's article could be make clearer.
I do now think I am seeing that the numbers in the chart probably just apply to a simple page with 18 links. If this is the case I am thinking that the readers of the article would be better serviced if the number applied to say a 6 page site that has a fully meshed internal link structure (no outbound links), or even better the ability to be able to put in the number of fully meshed pages they have.
If you have 18 PR5 links coming into your home page, there is a difference in the PR retained on the home page and the PR passed to the connected pages depending on the number of fully meshed pages in the site with no outbound links. The smaller the site the more PR the home page retains.
Most smaller sites link structures are fully meshed via the menu. It would be hard to make a model that would work for every site but one that would allow you to choose the size of your fully meshed site would be a starting place.

[Spyware Remover]

BobMutch:

This is some of the best info I have ever seen posted on any subject in any forum, ever.

Kudos to you for sharing.

AJ

[bobmutch]

Spyware Remover:Well er, thanks. If you want some good articles to read on PR I suggest you read Phil Craven's article Google's PageRank Explained (http://www.webworkshop.net/pagerank.html) and Ian Rogers article The Google Pagerank Algorithm (http://www.iprcom.com/papers/pagerank/). I also think Bob Wakfer's PageRank Calculation Chart (http://www.compar.com/infopool/articles/PR-calculation.html#page-rank-calculation-chart) is very useful.
This thread is currently discussing this chart and I am waiting for a responce from compar to my questions.
compar: Do you have some time Sir to address the questions I raised in my last post to you.

[bobmutch]

Four variables: how do we deal with them and make the numbers meaningful that are in the chart?
In some ways there appears that there is additional calculation that are required to use the chart, and it would seems those calculations would vary from site to site.
If the numbers from the chart can't be applied to any case, and I am not say they can't be, without some changes to the number then how can the numbers in the chart be used?
Do the numbers in the chart only apply where the links are to a single page that is not connected to any other pages?

Variables:
1. Chart is worked out for medium value PR -- no way to know if PRx is close to a high PR(x-1) or close to a low PR(x+1).
2. Chart is worked out for inbound links to have 50 outbound links -- no way to revalue if the links are greater or less. (I addressed revaluing in my article.)
3. Chart seems to not take into consideration internal link structure. For example inbound links to the home page in a 6 page site that has a fully meshed link structure will retain more PR than the same links going into a 14 page site that has a fully meshed link structure. (Phil Craven's Page Rank Grid Calculation shows this.)
4. Chart doesn't have any way to calculation the effect of outbound links on the page receiving the links or outbound links on any other pages in the site that the page recieving links is linked to.

Compar HELP!

[bobmutch]

I been thinking about doing a controlled study.

9 different single page sites with 3 sites getting a differnet set each of 101 PR4 links, 3 sites getting a differnt set each of 18 PR5 links and 3 sites getting a differnet set each of 3.339 PR6 links.
The links would be revalued using the revalue rule 6.25(PRx/TOL) PRx from my Page Rank Calculation (http://www.seocompany.ca/pagerank/page-rank-calculation.html) article.

Then using the same links set up 9 sites with a 6 page fully meshed linking structure and 9 sites with a 12 page fully meshed linking structure.

This study would address the following issues.
1. Compare the numbers from Wakfer's Chart to a real life controlled study.
2. Show the effect that adding a single page to a fully meshed site will have on the page that is receiving the links.

Different variables addressed:
1. Using 3 sites with 3 different sets of links will address the issue of the chart using "medium value" PR.
2. Using the revalue rule 6.25(PRx/TOL) PRx to revalue the links being received will address the issue of links having different numbers of Outbound links. If 3.339 PR6 link with 50 Outbound links each give a page a PR5. Then 1 PR6 with 15 (50/3.339 = 15) Outbound links will give a page a PR5.
3. Introducing the 9 single page sites into 6 page and 12 page sites with a fully meshed link structure will reflect the PR retained when moving an isolated page study into a real life site.
4. Now testing the effect of outbound links I will have to think on these things.

Who would be interesting in be involved in such a study? I can put up 27 domains, handle the hosting and construct the sites.

We would need some one that is very good at statistics, and a number of people that have conections for obtaining PR links easily.

What you all think?

[Spyware Remover]

Bob:

Truly THE most valuable post I have ever read and seen.

Thanks!

[bobmutch]

Spyware Remover: Have you read Phil Craven's article or Ian Roger's article on page rank. Now those are good articles. All I do is ask a bunch of questions.

[Scoreboard]

What you all think?

I think that is a freaking great idea and somebody needs to pick up your beer tab for a month if you undertake this endeavor!

[bobmutch]

Scoreboard: hehehehe well it all fun and games, it is sandbox work for me, I love internet stuff eheheheh.

[bobmutch]

Everyone: I changed my rule 4 formula as I found an error in it for calculating anything other than a PR8 and it also was to complicated. Here is the new rule. (TOL = Total Outbound Links)

If 50/TOL = Number of links, then here is our new rule.
Rule 4: Revaluing links: 50/TOL = New Link Number (i.e. 25TOL = 2 Links; 100TOL = 0.5 Links)
You then take these revalued links and use them over in rules 1 though 3.

I also made quite a few changes in the article Page Rank Calculation (http://www.seocompany.ca/pagerank/page-rank-calculation.html).

[compar]

Ok! I've been absent for a couple of days so let me set you all right on this.

1. As I clearly said in my original article PR is passed both by internal and external links to a page. In fact Google makes no distinction between internal and external in their listing of backlinks.

2. What you guys are talking about is commonly known as PR bled. The theory is that if a page has many outbound links, like a home page linking to all the pages in the site it belongs to, or just a home page with many links to other sites, -- it makes absolutely no difference either way, that is why this discussion of internal structure is meanlingless -- that it will pass less PR to all the pages it links to.

This is correct and is reflected in my 50 outbound links per page assumption. Once again whether those are links to internal pages or external pages make no difference.

So if a page has PR of a certain value and suddenly added 10 more internal or external links, then it would be passing less PR value to all pages. Assuming that these pages link back, which is normally the situation with internal pages, then after multiple calculation iterations each of these pages would have less PR to pass back, and on subsequent iterations the home page would have less PR to pass etc. etc.

3. For the purposes of my article and the understanding of the subject I think it is valid to assume that the internal linking structure of a page is fairly static. So new or additional inbound links will pass the values that I suggest. And no matter what the internal structure is this doesn't change the PR value received from an additional inbound link.

And if you guys think my article is too simplistic then don't read the fucking thing, and don't publish other articles that piggyback on it and try and capitalize on the popularity of my original work.

[bobmutch]

I have made some updates in my Page Rank Calculation (http://www.seocompany.ca/page-rank/page-rank-calculation.html) article. There were some mistakes in the calculation for revaluing links up or down to 50 total outbound links. I have also written up a new article that may be of interest called Sell Page Rank (http://www.seocompany.ca/page-rank/sell-page-rank.html). This compares the values of different page rank text link ads that are being sold on different auction on the internet.

[bobmutch]

compar: While it may not make any different whether the links are internal or external as far as concept and effects, the current accepted view of page rank is that links cause page rank bled. Even when there is a direct link back there still is page rank bled even though it is less.

According to general accepted views on page rank there will be a difference between a stand alone page with no outbound links at all, that has for example 18 medium PR7's (with 50 outbound links) linked to it, and the same page that has a non returning link to another page whether it is external or internal.

I don't see the question to be is there a difference in retained page rank but the real question is, is the different enough to affect the page rank value in the 1 to 10 scale that we see displayed on the little green bar.

If the difference in retained page rank is so small that it wouldn't change the green bar value except in an case where the page rank of the page is at the very bottom of the scale, then links don't matter except in the extreme case where the page rank value is at the bottom of the scale.

It is an accepted page rank view that whether you have 1 or 100 non returning outbound links you get the same bled. While returned links limit the page rank bled, the issue of whether the links are returned or not will have no mater if there is not is not enough bled in a non-returned links to effect the the green bar.

As I see no problems with agreeing to the above then the question remains, how much page rank is bled when an outbound link is made.

According to your chart it takes 18 medium valued PRx page links to product a PRx. If this is correct then each PRx link is transfering 1/18th PRx. Like wise when an outbound link is connected to a PRx page, 1/18 or 5.6% of the page rank will be transfered from that page.

If that calculation is correct and 5.6% of the PR is transfer then there wouldn't be more than that bled. If this is the case it is quite clear that the linking structure, be it internal, external, one way or fully meshed has little or almost no effect on the calculations and doesn’t need to be considered.

As far as my referring to yours or others published article or papers in the articles I write, this is an accepted practice in all fields in most countries except where there is totalitarian rule. It is also an accepted practice to question the results and theory's of publish papers. This is a good thing. This pratice enables proposed theories to be discussed, challenged, put to the test, revised, changed and even discounted where they are incorrect.

As a seeker of truth I welcome this process to any and all the articles I write.

[bobmutch]

compar: Also another thing, can you explain to me how 18 PRx's transfering only 1/50 (18 links with 50 total outbound links) of their PR can product a PRx on the page they link to? Wouldn't that be the same as a 0.36 of a PRx with only one out bound link producing a PRx?

I am revaluing the outbounds with 50/TOL = New Link Number

18/(50/50) = 18
18 medium value PRx with 50 outbounds each = 1 PRx

18/(50/25) = 9
9 medium value PRx with 25 outbounds each = 1 PRx

18/(50/5) = 1.8
1.8 medium value PRx with 5 outbounds each = 1 PRx

18/(50/1) = 0.36
0.36 medium value PRx with 1 outbound each = PRx

Now if you say my revalue calculation is incorrect then lets just look at 18 sets of PRx links producting 1 PRx 50 times. If it can product it once with 1 of the 50 outbound links then it can product it 50 times. That would mean that 18 PRx links can product 1 PRx 50 times. This doesn't seem possible.

That would be 1 PRx page producting 2.77 PRx pages (2.77x0.36 = 1).

If you roll back your outbound links to 18 instead of 50 (a huge 64% change) you still have 1 PRx producting 1 PRx. Or 18 PRx's producing 1 PRx 18 times.

Do you see an error in my calculations.

[compar]

compar: Also another thing, can you explain to me how 18 PRx's transfering only 1/50 (18 links with 50 total outbound links) of their PR can product a PRx on the page they link to? Wouldn't that be the same as a 0.36 of a PRx with only one out bound link producing a PRx?
............................................
Do you see an error in my calculations.
What I think I see is that you really don't understand the math behind my chart or the entire concept.

Have you downloaded the current PR Calculation Chart (ftp://ftp.compar.com/pub/PR.xls)? If you do you will find that I have changed the 50 outbound link assumption to 40 as I said earlier because this correlates so closely with the actual results that Rustybrick reports with his latest link statistics tool.

However all you have to do is substitute whatever number of outbound links you wish to experiment with in the field -- cell C19 -- that presently has "40" and the entire chart will recalculate on that basis.

I just reduced the outbound link assumption to 20 and it says that you then only require 7 links from any PR value to give a page the same value.

[bobmutch]

compar: I have not looked at the math behind your article so I am not going to fully understand the math. I will download the current PR Calculation Chart and take a peek at it.

I think my question was concerning the results of your chart. The old chart says that 18 PR8s of medium strength with a total of 50 outbound links, linked to a page will product a PR8. My comment was that this is the same as saying that 18 PR8's each linked to 50 different pages result in PR8 on those 50 pages. I just don't see how it that is possible. How can the links from 18 PR8's result in 50 PR8 pages?

[compar]

compar: I have not looked at the math behind your article so I am not going to fully understand the math. I will download the current PR Calculation Chart and take a peek at it.

I think my question was concerning the results of your chart. The old chart says that 18 PR8s of medium strength with a total of 50 outbound links, linked to a page will product a PR8. My comment was that this is the same as saying that 18 PR8's each linked to 50 different pages result in PR8 on those 50 pages. I just don't see how it that is possible. How can the links from 18 PR8's result in 50 PR8 pages?
I don't think that that is what the chart says or implies at all. It say that if a page had nothing else but 18 inbound links from pages with PR8, and assuming that the average number of outbound links from each of these pages was 50, then the recipent page would probably be given a PR8 rating. Or saying it another way the recipent page would have been passed enough PR points to cross the PR threshold. The other assumption here is that the Average PR points of each of the donor PR8 pages was the median of the PR8 point range.


I just don't see how it that is possible. How can the links from 18 PR8's result in 50 PR8 pages?
Look at the math. The median value of a PR8 is 2,682,431. If a page passes 85% of its value then a page with 50 OBL passses (2,682,431*.85)/50 which equals 45,601 PR points. Do the arthmetic yourself. It works.

Now the threshold point for a PR8 is 837,339. If you divide this by the 45,601 PR points that each of the 50 links pass then you will see that it only takes links from 18.362 pages to achieve the threshold value of 837,339.

The secret, or explanation for, this is the assumption that each PR8 in question has the median value of the PR8 range.

[bobmutch]

compar: Ok I see where I when wrong. I didn't take into consideration that the PR8's would be lower value PR8s.
The PR8 has a value of 837,339 to 4,527,522 with the medium value being 2,682,431. ((2,682,431*.85)/50) * 18 = 820,823 which is a tad short of a entry level PR8. The inbound 18 PR8's need to be an average of 2,736,402 or better to result in a bottom value PR8.

The multiplier is 0.306 [(0.85/50) * 18 = 0.306]

Lets look at the rest of them.
PR1 6 30 18 Short 5.5
PR2 30 164 97 Short 29
PR3 166 900 533 Short 163
PR4 915 4,948 2,931 Short 896
PR5 5,033 27,213 16,123 Short 4,933
PR6 27,681 149,670 88,675 Short 27,134
PR7 152,244 823,186 487,715 Short 149,240
PR8 837,339 4,527,522 2,682,431 Short 820,823
PR9 4,605,367 24,901,372 14,753,369 Short 4,514,530
PR10 25,329,516 136,957,543 81,143,530 Short 24,829,920

Lets check you 3.339 PRx results in a PR(x-1) [(0.85/50) * 3.339 = 0.0567]
Ok I ain't going to write them all out. All the calculations seem to be short.

[(0.85/50) * 19 = 0.323] works for all but the PR1, so it takes 19 medium PRx with 50 PRx to get a just-over-the-line PRx.

I suggest you modify your chart to give more than a just barely over the line PR. You may want to aim at a 1/4 value PR or even a 1/2 (medium) value PR.

I agree with cutting back to 40 inbounds and it seems to be a common number of external outbounds that people are using when they sell text link ads for there PR value.

The number of medium PRx's required to result in a medium value PRx is 59 medium value PRx's that have 50 outbounds. [50/0.85 = 59]
So it will take 59 PR8's of medium value with 50 outbounds to product 1 PR8 of medium value.

My next question is, what is you view on linked back internal links. Would you count those as outbounds also?

Oh by the way compar, I enjoy these discussions very much!

[joeychgo]

Geeze so many numbers ---lol I gotta tell you - im so confused!

[david_sakh]

same here man.

I think a respectable someone in the field should filter through all the rumors and come up with a comprehensive guide one of these days. The study of the internet has come into it's own.

[bobmutch]

david sakh: Well it is all theory any way, but it is interesting to put forth theorys and discuss them.

[comval]

Wow, Me head is aching. Can we "dumb it down" abit?

[anthonycea]

If you guys can't handle the heavy math, say out of the class, I flunked math too, if you don't understand it, go post in another thread and leave the Bob's to their math :cool: