====================================================================== SOURCE FILE: rr_district_A.yaml TABULATED FILE: rr_district_A_tabulated.txt ====================================================================== election_title: "Summability demo — District A, counted by Ranked Robin" scenario_description: |- District A of the two-district summability demo, counted by Ranked Robin (RCV-RR / Copeland) instead of IRV. Same ranked ballots as irv_district_A. The summable artifact is the pairwise (For–Against–Equal) matrix: B beats both A and C, so B is the Condorcet winner here. Combine with rr_district_B by ADDING the matrices cell-by-cell (see rr_combined) — the sum recovers the true winner without pooling ballots, the summability property IRV's count lacks. voting_method: RankedRobin num_winners: 1 ballots: |- 6:A 4:B 3:C>B>A expected_winners: - B ====================================================================== TABULATION RESULTS ====================================================================== --- Ranked Robin (RCV-RR / Copeland) Method (single winner) --- Tabulating 13 ballots (ranked ballots). Ballots: 6 × A 4 × B 3 × C > B > A Round-Robin — every pair, head-to-head (For – Against): B beats A 7 – 6 A beats C 6 – 3 B beats C 4 – 3 --- Pairwise (Round-Robin) Matrix --- Head-to-head / pairwise comparison — the Ranked Robin tally Legend: For - Equal Support - Against (row vs column) | A | B | C | ----------------------------------------- A > | --- |6 - 0 - 7 |6 - 4 - 3 | B > | 7 - 0 - 6 | --- |4 - 6 - 3 | C > | 3 - 4 - 6 |3 - 6 - 4 | --- | Win–loss record — Copeland score = wins + ½·ties (highest score wins; ties broken by total margin, then lot order): # Candidate W–L–T Copeland Margin Beats 1 B 2–0–0 2 +2 A, C 2 A 1–1–0 1 +2 C 3 C 0–2–0 0 -4 — Winner — Ranked Robin (RCV-RR): B beats every opponent head-to-head — the Condorcet winner. --- Smith Set (the generalized Condorcet winner) --- The smallest group whose every member beats every candidate outside it — the honest answer to "who is even in contention?". Smith set (1 of 3): B Outside (2): A, C One member ⇒ B is the Condorcet winner, beating every rival head-to-head. Ranked Robin (RCV-RR) winner B is INSIDE the Smith set. ✓ Guaranteed: Ranked Robin (Copeland) is Smith-efficient — every member of the set outscores every outsider, so the top of the win–loss table is always inside the set, however the tie among them is then broken. More: 07_Concepts/topics/smith_set.md