Definition
Reciprocal Rank Fusion (RRF) is a deterministic reranking algorithm used to combine multiple ranked result sets—typically from keyword-based BM25 and semantic vector search—into a single unified list. It calculates a final score by summing the reciprocals of a document's rank across all source lists, eliminating the need for complex score normalization.
It is a rank-based merging strategy, not a similarity metric or a model-based cross-encoder.
"A talent show where the winner is chosen by looking at the leaderboard positions from multiple different judges, rather than trying to average the judges' varied scoring points."
Conceptual Overview
Reciprocal Rank Fusion (RRF) is a deterministic reranking algorithm used to combine multiple ranked result sets—typically from keyword-based BM25 and semantic vector search—into a single unified list. It calculates a final score by summing the reciprocals of a document's rank across all source lists, eliminating the need for complex score normalization.
Disambiguation
It is a rank-based merging strategy, not a similarity metric or a model-based cross-encoder.
Visual Analog
A talent show where the winner is chosen by looking at the leaderboard positions from multiple different judges, rather than trying to average the judges' varied scoring points.