Topical Authority
Topical authority is the depth and breadth of expertise a website demonstrates on a given subject. Covering a topic and its related questions comprehensively helps every page in that cluster rank, rather than relying on individual pages competing entirely on their own.
Why it matters for your rankings
Topical authority explains why a specialist site with modest links outranks a larger generalist. Google increasingly evaluates whether a site is a credible source on a subject, not just whether one page matches a query.
This changes how content should be planned. Ten interconnected articles covering a subject exhaustively outperform ten unrelated articles chasing unrelated keywords, because the cluster reinforces itself through internal links and shared relevance. It also explains why new sites should start narrow. Attempting to cover everything produces shallow coverage of many subjects and authority in none, whereas owning one subject completely creates a base from which adjacent topics become winnable.
How to check it on your site
Map your existing coverage
List your pages by subject and identify which topics you cover deeply and which you touch once.
Find the gaps competitors fill
Compare your cluster against the subtopics ranking competitors cover that you do not.
Build hub and spoke structures
A comprehensive hub page linking to detailed subtopic pages, all linking back, makes the cluster explicit.
Resist unrelated expansion
Publishing outside your subject dilutes the signal rather than adding to it.