Google has moved to close a hole in their ranking algorithm known as Google or Link Bombing. The technique allowed webmasters to produce results based on numerous incidents of links pointing to the same document sharing the same keyword-charged anchor-text across as wide a number of sites as possible. Once a critical mass of sites ran the link with the same anchor text, the miracles of algorithmic search would do the rest and produce a top ranking prank. Well known examples included the phrase "Miserable Failure", "Talentless Hack", and "Drinks for Links".

According to a note posted by Matt Cutts to the Google Webmaster Central Blog, Google has improved on the way it analyses the link structure of the web. "Now we will typically return commentary, discussions, and articles about the Googlebombs instead," he writes.

In comments to a Danny Sullivan article (Google Kills Bush's Miserable Failure Search & Other Google Bombs) at SearchEngineLand.com, Bill Slawski points out a section of a patent application (Phrase-based indexing in an information retrieval system) written by Anna Patterson of San Jose Ca.

This approach has the benefit of entirely preventing certain types of manipulations of web pages (a class of documents) in order to skew the results of a search. Search engines that use a ranking algorithm that relies on the number of links that point to a g

iven document in order to rank that document can be "bombed" by artificially creating a large number of pages with a given anchor text which then point to a desired page. As a result, when a search query using the anchor text is entered, the desired page is typically returned, even if in fact this page has little or nothing to do with the anchor text. Importing the related bit vector from a target document URL1 into the phrase A related phrase bit vector for document URL0 eliminates the reliance of the search system on just the relationship of phrase A in URL0 pointing to URL1 as an indicator of significance or URL1 to the anchor text phrase.

Matt Cutts posts a complimentary no comment response directly beneath.

Meanwhile, over at his Infothought blog, Seth Finkelstein does a bit of reverse engineering trying to figure out how the algo change works.

"Just as a speculation, and not tested much, here's my guess at the algorithm, *something like*:

IF the links to the page contain [BOMB] and

0) There are lot of links with anchortext [BOMB]

1) [BOMB] does not appear on the page or metadata

2) [BOMB] is the most common anchortext in links to the page

3) There are "very few" links of the form [BOMB otherwords]

THEN ignore all links with [BOMB]

This would preserve the ranking of pages talking about it, since they'll have the words on the page, even in the title.

We can test this by adding lots of links with both the expected text and [BOMB]: George Bush: "Miserable Failure""

Though the technique is often named after the number one search engine, it tends to work on all algorithmic search engines and continues to produce fairly predictable results on Yahoo, MSN and ASK.