{
  "datasetId": "nfcorpus",
  "tier": 1,
  "liveTechnique": "bm25 (title+text multi_match)",
  "offlineValidated": {
    "bm25NdcgAt10": 0.3273,
    "publishedBm25": 0.325,
    "bgeHybrid": "universal core technique; validated offline for Tier 1 (see technique matrix)",
    "note": "BGE hybrid live serving requires a resident kNN index; on the free tier it is offline-validated. Lexical BM25 is live for Tier 1."
  },
  "coreArchitecture": "ARCH-0.5 (BM25 + BGE hybrid)"
}