Hybrid Search RAG: BM25 + Vector Search in Production

The retrieval problem most RAG teams ignore The majority of RAG failures are not hallucination failures. They are retrieval failures. Research across enterprise document Q&A deployments consistently places the fraction of bad answers attributable to retrieval - wrong documents returned, relevant documents missed, rank order confused - at a clear majority (per production analysis, frequently cited around 70% or higher). The LLM never had a chance: it was reasoning over the wrong evidence from the start.