Anchor-Spam (Penguin legacy)
This system detects manipulative link patterns in anchor text, the clickable text of a hyperlink.
01What it measures
This system detects manipulative link patterns in anchor text, the clickable text of a hyperlink. A page that is linked exclusively with exact keyword texts ('Berlin weather', 'free weather forecast') looks unnatural, like deliberate SEO manipulation. Penguin is the historic Google update that addressed this problem. Its logic lives on in today's system.
02Derived from
Two fields: phraseAnchorSpamPenalty, a penalty score for over-optimized anchors, and IsAnchorBayesSpam, a classifier that gives a yes/no verdict on whether anchor spam is present.
03How it's measured
Two spam fields for anchor text. phraseAnchorSpamPenalty = a penalty for over-optimized anchor phrases. IsAnchorBayesSpam = a yes/no flag from a Bayes classifier (a statistical spam filter) for anchor spam. [B fields]
04Why it counts here
Trust is primary: anchor manipulation is a direct breach of trust toward Google and users. Authority is indirect, because the link profile influences a page's authority.
05What to do about it
For link building: natural, descriptive link texts are better than keyword-optimized ones. Anyone who asks external partners for links should not prescribe ready-made anchor texts. Internal links with varied link texts ('Hamburg rain radar', 'North Sea storm warning') instead of always the same phrase reduce the risk.