The knobs run out

Part one ended at a plateau: 34 of 46 cases passing at the honest configuration, recall@3 thirteen points above recall@1, and a hypothesis. The right page was almost always retrieved and simply was not first, so the problem had to live wherever "first" gets decided, and in a hybrid engine that place is rank fusion. RRF's conventional k = 60 is calibrated for TREC-scale runs fusing thousand-deep lists. On a 19-document corpus the reciprocal-rank curve is nearly flat (rank 1 versus rank 2 is 1/61