====================================================================== SOURCE FILE: p3_sincere_ranked_robin.yaml TABULATED FILE: p3_sincere_ranked_robin_tabulated.txt ====================================================================== election_title: "P3 sincere — Ranked Robin elects Edinburgh (the baseline every manipulation attacks)" scenario_description: |- Zwicker's profile P3 (Handbook of Computational Social Choice ch. 2, Definition 2.3), 7 voters and 5 candidates, cast SINCERELY. Edinburgh goes 3-1 head-to-head and is the Copeland/Ranked Robin winner with a symmetric Copeland score of +2; Bergen is -2 and the rest are 0, exactly the numbers the book prints. There is NO Condorcet winner (Dublin beats Edinburgh 5-2, so nobody beats everybody). This is the baseline: the two Athens-first voters are about to see their LAST choice, Edinburgh, win — which is precisely the pressure the book uses to define single-voter manipulability. The manipulated counterparts are p3_manip_reversal_rr.yaml and p3_manip_compromise_rr.yaml. bv_test_id: BV2253 bv_election_id: 4w96tr bv_results_url: https://bettervoting.com/4w96tr/results voting_method: RankedRobin num_winners: 1 lot_numbers: [Athens, Bergen, Cork, Dublin, Edinburgh] ballots: |- 2:Edinburgh>Cork>Athens>Dublin>Bergen 3:Dublin>Edinburgh>Bergen>Cork>Athens 2:Athens>Bergen>Cork>Dublin>Edinburgh expected_winners: - Edinburgh # file: p3_sincere_ranked_robin.yaml ====================================================================== TABULATION RESULTS ====================================================================== --- Ranked Robin (RCV-RR / Copeland) Method (single winner) --- Tabulating 7 ballots (ranked ballots). Ballots: 2 × Edinburgh > Cork > Athens > Dublin > Bergen 3 × Dublin > Edinburgh > Bergen > Cork > Athens 2 × Athens > Bergen > Cork > Dublin > Edinburgh Round-Robin — every pair, head-to-head (For – Against): Edinburgh beats Cork 5 – 2 Edinburgh beats Athens 5 – 2 Dublin beats Edinburgh 5 – 2 Edinburgh beats Bergen 5 – 2 Cork beats Athens 5 – 2 Cork beats Dublin 4 – 3 Bergen beats Cork 5 – 2 Athens beats Dublin 4 – 3 Athens beats Bergen 4 – 3 Dublin beats Bergen 5 – 2 --- Pairwise (Round-Robin) Matrix --- Head-to-head / pairwise comparison — the Ranked Robin tally Legend: For - Equal Support - Against (row vs column) | Edinburgh | Cork | Athens | Dublin | Bergen | --------------------------------------------------------------------------------- Edinburgh > | --- | 5 - 0 - 2 | 5 - 0 - 2 | 2 - 0 - 5 | 5 - 0 - 2 | Cork > | 2 - 0 - 5 | --- | 5 - 0 - 2 | 4 - 0 - 3 | 2 - 0 - 5 | Athens > | 2 - 0 - 5 | 2 - 0 - 5 | --- | 4 - 0 - 3 | 4 - 0 - 3 | Dublin > | 5 - 0 - 2 | 3 - 0 - 4 | 3 - 0 - 4 | --- | 5 - 0 - 2 | Bergen > | 2 - 0 - 5 | 5 - 0 - 2 | 3 - 0 - 4 | 2 - 0 - 5 | --- | 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 Edinburgh 3–1–0 3 +6 Cork, Athens, Bergen 2 Dublin 2–2–0 2 +4 Edinburgh, Bergen 3 Cork 2–2–0 2 -2 Dublin, Athens 4 Athens 2–2–0 2 -4 Dublin, Bergen 5 Bergen 1–3–0 1 -4 Cork Winner — Ranked Robin (RCV-RR): Edinburgh the most head-to-head wins (3). --- 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 (5 of 5): Edinburgh, Cork, Athens, Dublin, Bergen Outside (0): — More than one member ⇒ NO Condorcet winner: the top of the tournament is a cycle, so the strongest "candidate" is a set, not a person. Which member of the set should win is exactly what Minimax / Ranked Pairs / Schulze disagree about — see 05_Ranked_Robin/01_Learn/cycle_resolution.md. Note: the Copeland leaders (Edinburgh) are only part of the set — the win–loss table's top block understates how wide the contention is. Ranked Robin (RCV-RR) winner Edinburgh 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