Anchor-Spam (Penguin legacy)

This system detects manipulative link patterns in anchor text (the clickable text of hyperlinks). When a page is linked to exclusively with exact keyword texts ('Berlin weather', 'free weather forecast'), it looks unnatural and like deliberate SEO manipulation. Penguin is the historic Google update that addressed this problem — the logic lives on in today's system.

phraseAnchorSpamPenalty (penalty score for over-optimized anchors) and IsAnchorBayesSpam (a classifier that gives a yes/no verdict on whether anchor spam is present).

phraseAnchorSpamPenalty = a penalty for over-optimized anchor phrases; IsAnchorBayesSpam = a Bayes-classifier flag (yes/no) for anchor spam. [B fields]

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.

For link building: natural, descriptive link texts are better than keyword-optimized ones. When asking external partners for links, don't prescribe ready-made anchor texts. Varied internal link texts ('Hamburg rain radar', 'North Sea storm warning') instead of always repeating the same phrase reduces the risk.