====================================================================== SOURCE FILE: center_squeeze_voteline_1d.yaml TABULATED FILE: center_squeeze_voteline_1d_tabulated.txt ====================================================================== paradoxes: [condorcet-winner] election: election_title: Center squeeze — the voteline 1D spectrum (Red / Green / Yellow) election_description: |- The classic 1-D spectrum demo (zesty.ca/voting/voteline): Red on the left, Green in the center, Yellow on the right, with voters spread across the line. Green is the CONDORCET winner (beats Red AND Yellow head-to-head) but has the FEWEST first choices (31.3%), so RCV-IRV eliminates Green first and YELLOW wins (52.9%) — the center squeeze. STAR advances Green on strength of support and wins the runoff 65-35. Plurality also picks Yellow. Approval / Borda / Condorcet / Ranked Robin all pick Green. Scores are a reasonable 1-D spatial model (own side 5, adjacent center 3, far side 0-1). Weights are percentages x10. Level 201/301. Lesson: 06_Other/RCV_IRV/concepts/RCV_IRV_center_squeeze.md races: - race_id: '0' race_description: "1-D spectrum: Red (left) / Green (center) / Yellow (right)" num_winners: 1 voting_method: STAR ballots: |- Red, Green, Yellow 332 × 5, 3, 0 # red > green > yellow (left bloc) 138 × 3, 5, 1 # green > red > yellow (center-left) 175 × 1, 5, 3 # green > yellow > red (center-right) 353 × 0, 3, 5 # yellow > green > red (right bloc) lot_numbers: [Red, Green, Yellow] expected_results: winners: - Green # file: center_squeeze_voteline_1d.yaml ====================================================================== TABULATION RESULTS ====================================================================== === Center squeeze — the voteline 1D spectrum (Red / Green / Yellow) === 1-D spectrum: Red (left) / Green (center) / Yellow (right) --- Runoff (Preference) Matrix --- Head-to-head / pairwise comparison Legend: For - Equal Support - Against * indicates Top 2 Finalist | Red | * Green | * Yellow | ------------------------------------------------------------------------- Red > | --- |332 - 0 - 666 |470 - 0 - 528 | * Green > | 666 - 0 - 332 | --- |645 - 0 - 353 | * Yellow > | 528 - 0 - 470 |353 - 0 - 645 | --- | [Condorcet Winner] Condorcet Winner: Green — matches the STAR winner [Condorcet Loser] Condorcet Loser: Red — loses every head-to-head matchup [Divergence from STAR] STAR = Green Choose-One (Plurality) = Yellow (differs from STAR) RCV-IRV = Yellow (differs from STAR) Note: no ballots had tied scores, so RCV-IRV vs STAR here is a genuine method difference, not a tie-breaking artifact. Note: Ranked Robin (RCV-RR) agrees with STAR, so RCV-IRV is the lone outlier — the classic center-squeeze signature. Full round-by-round reports (generated for review): RCV-IRV rounds: cases_tabulated/center_squeeze_voteline_1d_RCV-IRV_tabulated.txt --- STAR Voting Method (single winner) --- [STAR Voting] Tabulating 998 ballots. Count × Red,Green,Yellow 353 × 0, 3, 5 332 × 5, 3, 0 175 × 1, 5, 3 138 × 3, 5, 1 [Score Distribution] (how many ballots gave each star rating) Score Candidate 5 4 3 2 1 0 | Total Avg Red 332 0 138 0 175 353 | 2249 2.3 Green 313 0 685 0 0 0 | 3620 3.6 Yellow 353 0 175 0 138 332 | 2428 2.4 [STAR Voting: Scoring Round] The two highest-scoring candidates advance to the next round. Green -- 3620 -- First place Yellow -- 2428 -- Second place Red -- 2249 Green and Yellow advance. [STAR Voting: Automatic Runoff Round] The candidate preferred in the most head-to-head matchups wins. Green -- 645 -- First place Yellow -- 353 Equal Support -- 0 Green wins. Runoff math: 998 ballots cast − 0 Equal Support (no preference between the two finalists) ─── 998 voters with a preference (majority = 500) Green 645 (65%) · Yellow 353 (35%) [STAR Voting: Winner — STAR Voting Method (single winner)] Green