Tell which update hit you by matching the exact dates of your traffic movement to documented update timelines, then checking which content pattern was affected. Date alignment narrows the field: pull the precise day your traffic shifted and line it up against the published start and end dates of the updates that rolled out around then, because a drop that begins on one update’s rollout date and not another’s points you at the right one. Dates alone can be ambiguous when rollouts overlap, so the second half of the method is to read which kind of content moved. That date-plus-affected-pattern combination is the discriminator. Guessing the update without checking the dates first is how people fix the wrong thing.
The affected-pattern read works because different updates target different things. A core update broadly re-assesses quality and relevance across many sites, so its effects tend to be wide and tied to overall helpfulness. A spam update targets spammy patterns and manipulative tactics, so it tends to hit pages with those characteristics. A niche or system-specific update hits its own area (reviews, a particular content type), so its damage clusters there. By asking what was hit, thin pages broadly, spam-pattern pages, or one content category, you cross-check the date and infer which update is the likely cause.
Both halves matter because either one alone misleads. Dates without the pattern can leave you stuck between two overlapping rollouts. The pattern without the dates can have you blaming an update that did not even run when your traffic moved. Run them together and the suspect usually resolves to one.
For your next diagnosis, start by aligning your drop dates against the documented update timelines, then characterize the content that lost ground and match it to that update’s known focus. One caution worth flagging: update names, dates, and the specifics of what each one targets change over time, so confirm the current timeline and each update’s documented focus against Google’s own up-to-date sources before you act on the conclusion.