links

Hilltop constructs a query-specific authority graph by restricting link-based scoring to "expert documents" - non-affiliated pages containing topically relevant outbound links - thereby isolating genuine editorial endorsement from self-serving or incidental citation networks. Standard PageRank-style algorithms fail to distinguish between links reflecting deliberate expert judgment and links reflecting co-location, reciprocity, or structural spam, producing authority scores that reward link acquisition rather than topical relevance. This implies that ranking durability depends on source qualification upstream of link weighting: a page's authority signal degrades predictably when the underlying linker set lacks demonstrable topical expertise, making expert-filtered link graphs structurally resistant to manipulation at scale.