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Pineapple progression (2/3) — 25% wins Choose-One, but Cheese is the real choice

▶ Live on BetterVoting: vote · results ↗ (election mvxbxr · test BV2217) — an independent tabulator to check the winners below against.

Bucket — IRV_OUTLIER_RR_WITH_STAR: RCV-IRV is the outlier (center squeeze)

Generated by STARVote_LH_tabulation_engine/tools_adam/scripts/build_divergence_index.py — rebuilt from the election file; do not hand-edit.

What happens

STAR elects Cheese — and so do Ranked Robin and Condorcet, because Cheese is the head-to-head (pairwise) winner, beating every rival one-on-one. RCV-IRV instead elects Pineapple: Cheese collects fewer top (first-choice) votes, so IRV eliminates Cheese early, and those ballots transfer to Pineapple. This is the classic center squeeze — the broadly acceptable candidate is knocked out by round-by-round elimination even though a majority prefers them in a direct matchup. Two methods (STAR + RR) against one (RCV-IRV): IRV is the outlier.

Winners by method

Method Winner
STAR Cheese
RCV-IRV Pineapple
Ranked Robin (RCV-RR) Cheese
Approval Cheese
Range / Score Cheese
Condorcet Cheese

Flags: none

Source election: method_comparisons/minority_winner_progression/cases/pineapple_25pct.yaml · STAR tabulated mirror: pineapple_25pct_tabulated.txt

5 candidates, 100 ballots.

The ballots

Each row is a group of identical score ballots (0 = no support, 5 = max).

Count Pineapple Anchovy Mushroom Olive Cheese
25 5 0 0 0 4
23 0 5 0 0 4
23 0 0 5 0 4
23 0 0 0 5 4
6 0 0 0 0 5

STAR result (official)

Scoring round (sum of scores): Cheese 406, Pineapple 125, Anchovy 115, Mushroom 115, Olive 115

Finalists (top two): Cheese and Pineapple

Automatic runoff: Cheese 75 vs Pineapple 25

STAR winner: Cheese

Full LH STAR engine report:

--- Runoff (Preference) Matrix ---
Head-to-head / pairwise comparison
Legend: For - Equal Support - Against
        * indicates Top 2 Finalist
                  |  * Pineapple  |  * Cheese    |
--------------------------------------------------
    * Pineapple > |      ---      |25 -  0 - 75  |
       * Cheese > | 75 -  0 - 25  |     ---      |

[Divergence from STAR]
  STAR                   = Cheese
  Choose-One (Plurality) = Pineapple   (differs from STAR)
  RCV-IRV                = Pineapple   (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.

--- STAR Voting Method (single winner) ---
 Tabulating 100 ballots.
Count × Pineapple,Anchovy,Mushroom,Olive,Cheese
   25 ×         5,      0,       0,    0,     4
   23 ×         0,      5,       0,    0,     4
   23 ×         0,      0,       5,    0,     4
   23 ×         0,      0,       0,    5,     4
    6 ×         0,      0,       0,    0,     5

[Score Distribution] (how many ballots gave each star rating)
                   Score
Candidate   5   4   3   2   1   0  | Total   Avg
Pineapple  25   0   0   0   0  75  |   125   1.3
Anchovy    23   0   0   0   0  77  |   115   1.2
Mushroom   23   0   0   0   0  77  |   115   1.2
Olive      23   0   0   0   0  77  |   115   1.2
Cheese      6  94   0   0   0   0  |   406   4.1

Scoring Round
 The two highest-scoring candidates advance to the next round.
   Cheese        -- 406 -- First place
   Pineapple     -- 125 -- Second place
   Anchovy       -- 115
   Mushroom      -- 115
   Olive         -- 115
 Cheese and Pineapple advance.

Automatic Runoff Round
 The candidate preferred in the most head-to-head matchups wins.
   Cheese        -- 75 -- First place
   Pineapple     -- 25
   Equal Support --  0
 Cheese wins.
   Voters with a preference: 100 of 100 (no Equal Support).
   Cheese 75 (75%) vs Pineapple 25 (25%); majority = 51.

Winner — STAR Voting Method (single winner)
 Cheese

RCV-IRV — round by round

--- RCV / Instant-Runoff Voting (single winner) ---
 Tabulating 100 ballots (converted from score ballots; 0 = unranked, equal scores broken by candidate priority).

Ballots:
   the ranking RCV-IRV reads (0 = unranked, equal scores broken by priority);
   the source score ballot follows in () per column: Pineapple, Anchovy, Mushroom, Olive, Cheese
    25 ×   Pineapple > Cheese      (5, 0, 0, 0, 4)
    23 ×   Anchovy > Cheese      (0, 5, 0, 0, 4)
    23 ×   Mushroom > Cheese      (0, 0, 5, 0, 4)
    23 ×   Olive > Cheese      (0, 0, 0, 5, 4)
     6 ×   Cheese      (0, 0, 0, 0, 5)

ROUND 1
Candidate      Votes  Status
-----------  -------  --------
Pineapple         25  Hopeful
Anchovy           23  Hopeful
Mushroom          23  Hopeful
Olive             23  Hopeful
Cheese             6  Rejected

ROUND 2
Candidate      Votes  Status
-----------  -------  --------
Pineapple         25  Hopeful
Anchovy           23  Hopeful
Mushroom          23  Hopeful
Olive             23  Rejected
Cheese             0  Rejected
Blank Votes        6  Rejected

ROUND 3
Candidate      Votes  Status
-----------  -------  --------
Pineapple         25  Hopeful
Anchovy           23  Hopeful
Mushroom          23  Rejected
Olive              0  Rejected
Cheese             0  Rejected
Blank Votes       29  Rejected

FINAL RESULT
Candidate      Votes  Status
-----------  -------  --------
Pineapple         25  Elected
Anchovy           23  Rejected
Mushroom           0  Rejected
Olive              0  Rejected
Cheese             0  Rejected
Blank Votes       52  Rejected


Winner(s) — RCV / Instant-Runoff Voting (single winner)
  Pineapple

--- 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 5): Cheese
   Outside (4):        Pineapple, Anchovy, Mushroom, Olive
   One member ⇒ Cheese is the Condorcet winner, beating every rival head-to-head.
   RCV-IRV winner Pineapple is OUTSIDE the Smith set. ✗
      Every member of the set (Cheese) beats Pineapple head-to-head, yet
      RCV-IRV elected Pineapple anyway. RCV-IRV is not Smith-efficient (nor
      Condorcet-efficient) — this is the shape a center squeeze leaves behind.
   More: 07_Concepts/topics/smith_set.md

NOTE: a generated cross-method view of the STAR ballots, for comparison only — not the official STAR result.

Ranked Robin (RCV-RR) — every pair, head-to-head

--- Ranked Robin (RCV-RR / Copeland) Method (single winner) ---
 Tabulating 100 ballots (score ballots).

Ballots:
   the ranking Ranked Robin reads ("=" = tied); source scores follow in () per column: Pineapple, Anchovy, Mushroom, Olive, Cheese
    25 × Pineapple > Cheese > Anchovy=Mushroom=Olive      (5, 0, 0, 0, 4)
    23 × Anchovy > Cheese > Pineapple=Mushroom=Olive      (0, 5, 0, 0, 4)
    23 × Mushroom > Cheese > Pineapple=Anchovy=Olive      (0, 0, 5, 0, 4)
    23 × Olive > Cheese > Pineapple=Anchovy=Mushroom      (0, 0, 0, 5, 4)
     6 × Cheese > Pineapple=Anchovy=Mushroom=Olive      (0, 0, 0, 0, 5)

Round-Robin — every pair, head-to-head (For – Against):
   Pineapple  beats Anchovy     25 – 23
   Pineapple  beats Mushroom    25 – 23
   Pineapple  beats Olive       25 – 23
   Cheese     beats Pineapple   75 – 25
   Anchovy    ties  Mushroom    23 – 23
   Anchovy    ties  Olive       23 – 23
   Cheese     beats Anchovy     77 – 23
   Mushroom   ties  Olive       23 – 23
   Cheese     beats Mushroom    77 – 23
   Cheese     beats Olive       77 – 23

--- Pairwise (Round-Robin) Matrix ---
Head-to-head / pairwise comparison — the Ranked Robin tally
Legend: For - Equal Support - Against   (row vs column)
              |  Pineapple   |  Anchovy    |  Mushroom   |   Olive     |   Cheese    |
--------------------------------------------------------------------------------------
  Pineapple > |     ---      |25 - 52 - 23 |25 - 52 - 23 |25 - 52 - 23 |25 -  0 - 75 |
    Anchovy > | 23 - 52 - 25 |    ---      |23 - 54 - 23 |23 - 54 - 23 |23 -  0 - 77 |
   Mushroom > | 23 - 52 - 25 |23 - 54 - 23 |    ---      |23 - 54 - 23 |23 -  0 - 77 |
      Olive > | 23 - 52 - 25 |23 - 54 - 23 |23 - 54 - 23 |    ---      |23 -  0 - 77 |
     Cheese > | 75 -  0 - 25 |77 -  0 - 23 |77 -  0 - 23 |77 -  0 - 23 |    ---      |

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  Cheese     4–0–0         4    +212  Pineapple, Anchovy, Mushroom, Olive
    2  Pineapple  3–1–0         3     -44  Anchovy, Mushroom, Olive
    3  Anchovy    0–2–2         1     -56  —
    4  Mushroom   0–2–2         1     -56  —
    5  Olive      0–2–2         1     -56  —

Winner — Ranked Robin (RCV-RR): Cheese
   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 5): Cheese
   Outside (4):        Pineapple, Anchovy, Mushroom, Olive
   One member ⇒ Cheese is the Condorcet winner, beating every rival head-to-head.
   Ranked Robin (RCV-RR) winner Cheese 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