Inspired by the Google leaks earlier this year, I've had a hypothesis that the HCUs (Helpful Content Updates) - part of Google's core ranking system since March 2024 - are about something almost completely separate from Google's messaging, and most SEOs' tactical understanding.
In their original announcement in August 2022, Google wrote that this was a sitewide signal, but mainly affected by document-level factors intended to judge the helpfulness of content. Many SEOs, including myself, speculated that this might be a highly prescient first move against a new wave of LLM-generated spam. Google, through some complex machine learning methodology, was judging the subjective quality of content, or so we were to believe.
Googlers often hint that their search engine is simpler than we think, and my data backs this up. The HCU appears to be based, at least in part, on an older and simpler system. After studying the last three HCUs & post-HCU-merged Core updates from September 2023, March 2024, and August 2024, there's something that demoted sites overwhelmingly have in common. Before we get there, though, a bit of scene setting.