def sample_unmerged_for_review(
    records: list[dict],
    merged_ids: set[int],
    sample_size: int = 50,
) -> list[dict]:
    unmerged = [r for i, r in enumerate(records) if i not in merged_ids]
    by_jurisdiction: dict[str, list[dict]] = {}
    for r in unmerged:
        jur = r.get("jurisdiction_code", "UNK")
        by_jurisdiction.setdefault(jur, []).append(r)

    flagged = []
    for jur, recs in by_jurisdiction.items():
        total_in_jur = sum(1 for r in records if r.get("jurisdiction_code") == jur)
        merge_rate = 1.0 - len(recs) / total_in_jur
        if merge_rate < 0.3 and total_in_jur > 20:
            flagged.extend(recs[:10])

    return flagged[:sample_size]