Definition
A broad change to Google’s ranking systems, released several times a year. Affiliate and gambling sites are often hit first and hardest.
A core update is not a penalty and not a fix for a specific tactic. It is a revision of how quality is assessed across the whole index, announced in advance and rolled out over one to three weeks. Sites do not lose visibility because they were caught at something; they lose it because the comparison against everything else changed.
How it works
Rollouts are gradual and unstable while they run. Rankings move, settle, move again, and reading the first days as a verdict leads to changes made on noise.
Google’s own guidance on recovery is consistent and unsatisfying: there is nothing to undo, because nothing was flagged. Sites that recover usually do so at a later update, after the material difference between them and the pages that replaced them has actually been closed.
That is the part worth internalising. A core update reveals a judgement that was already being formed; the drop is the moment it becomes visible, not the moment it was made.
Why it matters in iGaming
Affiliate comparison content sits exactly where these updates bite: commercial pages, crowded topics, money-and-health classification, heavy reliance on links. Several updates in recent years have reshaped the first page of gambling comparison terms almost completely.
The volatility compounds. A site rebuilt in a hurry after one update frequently fares worse at the next, because the rebuild chased a theory about the algorithm rather than closing the gap in the pages themselves.
Example
A comparison site loses half its visibility over a two-week rollout. The pages that replaced it are not better optimised — they carry an author who demonstrably knows the subject, figures that are dated and sourced, and fewer pages covering the same ground. Three updates later the site recovers, after being rewritten rather than retuned.
Common mistakes
- Reacting during the rollout. Rankings are unstable for days; changes made then are measured against noise and usually cannot be disentangled afterwards.
- Looking for the tactic that was punished. Core updates do not target tactics, and the search for one produces a list of superstitions.
- Rebuilding everything. The pages that held up are evidence about what worked; replacing them along with the rest destroys the only data available.