Three or more URLs compete for the same query (Site diversity)

Google documents that its site diversity system generally shows no more than two listings per site in top results and usually treats subdomains as the same site. Extra pages on the same query compete for those slots. The two-listing limit is Verified; the cost of cannibalisation is inferred.

Pick one primary URL per intent, merge or redirect overlapping pages, differentiate pages that serve genuinely different intents, and align internal links and canonicals to the primary URL.

1. Export Search Console performance data by query and page for the last 3 months (via the API or Looker Studio to avoid row limits).
2. Include subdomain properties so subdomain URLs are counted with the root domain.
3. For each query with meaningful impressions, count distinct URLs with impressions and note position changes over time.
4. Flag queries where three or more URLs share impressions or where the ranking URL changes week to week.

Written for the Site diversity system page (evidence: Confirmed). Google has not documented this system in a way a site can test directly, so this check measures a proxy for it, not the system itself.

Direct for the affected queries: consolidating usually stabilises which URL ranks. Estimate only for traffic gains.

Google's ranking systems guide on the site diversity system; launch statements reported by Search Engine Land and Search Engine Roundtable.