Comments on: Calling Matt Cutts To The Bat Phone

By: Halfdeck

Halfdeck — Thu, 17 Jul 2008 17:09:00 +0000

"there is no reason to add the same link to the spidering queue"

Links aren't just pushed on the crawl queue. Google also needs to keep a record of what links exist on a given page. That'a separate list, and its what eventually decides how Google constructs its link graph.

Google may also blindly store all the links during crawl and process them later, post-crawl. That frees up CPU resources and allows Google to use more complicated algoes to sort out the links. You don't need to filter out dupes on a list to crawl correctly, though Googlebot needs to obey nofollows.

The biggest lesson here though is its harder than people think to set up an SEO test. If there are 10 factors at play but you assume there's only one factor at play, you can end up with a wacked conclusion.

By: mvandemar

mvandemar — Tue, 15 Jul 2008 02:00:00 +0000

@RedCardinal, the way my tests came out it seems as if the first link is the only one that is counted. That means that only the first anchor text passes any relevancy, and if that happens to be nofollowed then none of the subsequent links to the same page pass value. I explained what I think is happening here, but basically I think it has to do with efficiency. The routines that spider pages are (I am assuming) quite separate from those that actually assign ranking values. When the page is parsed for links, it probably de-dupes them, since there is no reason to add the same link to the spidering queue twice. It also applies the nofollow tag, since, again, if it's nofollowed on that page there is no reason to add it to the queue (from that page, anyways, but of course there might be a link to the same page elsewhere that is followed). My guess is that these two functions are overlapping when there are multiple links to one target and the first is nofollowed.

I am also guessing that this just happened, and was a side effect rather than being something that they did by design. They could just as easily switch the order of operations, and remove the nofollowed links first, and then dedupe, in which case if the first link were nofollowed the second link would become the first. Now that attention has been drawn to it, who knows, they may in fact do that.

By: RedCardinal

RedCardinal — Sat, 12 Jul 2008 03:10:00 +0000

Hmm… I think the question has to be broken down into chunks. It may be that Google counts the second anchor, but doesn’t include the anchor text. Then you’ve got the Pagerank element, and you can throw NOFOLLOW in for good measure.

Any follow-ups from mvandemar on his testing?

By: Neyne

Neyne — Fri, 11 Jul 2008 19:40:00 +0000

I don’t think he is going to do the tests for you…

By: jerry

jerry — Fri, 11 Jul 2008 18:44:00 +0000

Matt, what if the first text on a page is nofollowed, are the rest of the links treated as follow’d links? What if the second link is nofollow’d but the first is not?

By: Matt Cutts

Matt Cutts — Fri, 11 Jul 2008 16:29:00 +0000

Dudibob, no, I confirmed the converse: if the anchortext is the same, we’ll typically drop the second link.

This is the sort of thing where people can run experiments to see whether different anchortexts flow in various ways.

By: Dudibob

Dudibob — Fri, 11 Jul 2008 12:28:00 +0000

Wait wait wait, so Matt, your saying (simplified) if the second anchor text is different to the first, Google will pass (some) value?

By: Marion

Marion — Thu, 10 Jul 2008 21:27:00 +0000

I guess it depends on how you define the word… probably/is…

By: mvandemar

mvandemar — Thu, 10 Jul 2008 20:56:00 +0000

Matt, what about differing anchor texts though? I (and some others) ran some tests that seem to indicate that not only does only the first link count, but if you nofollow that link then none of the others to that page will count either:

Single Source Page Link Test Using Multiple Links With Varying Anchor Text

I mean, it makes sense in a way, but knowing for sure that it works that way (whether or not it is what is intended) would be good, especially when it comes to navigation and PageRank sculpting, etc.

Thanks.

By: Matt Cutts

Matt Cutts — Thu, 10 Jul 2008 20:25:00 +0000

Your question is short, but the answer is more complex. Typically if the anchortext on the two links is identical, we would probably drop one of those links.