ModelForge/docs/architecture/adr/0025-frozen-retrieval-candidate-pools.md

ADR-0025: Freeze first-stage candidate pools for reranking comparisons

Status

Accepted — 2026-08-25.

Decision

Control and reranked results must consume the same immutable ordered candidate pool, identified by suite case, embedding source, corpus and retrieval configuration. Persist IDs, scores and content hashes, never text. Top 40 is a ceiling, not permission to pad an in-scope pool.

Consequences

Reranker gains cannot be caused by retrieval drift. A reranker cannot claim recovery of an item not present in the pool, and mismatched pools are non-comparable.