Retrieval metrics and vector-DB shape — recall@k, MRR, and why the filter runs before the search — step 4 of 7

MRR rewards putting the right chunk FIRST. Each query contributes the reciprocal of the rank where its first relevant hit appeared: rank 1 → 1.0, rank 2 → 0.5, rank 3 → 0.33. Average those and you have MRR.

Fill the blank so each query adds its reciprocal rank.

Expected output:

MRR: 0.61