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More stars, fewer voters — the runoff overturns the score leader

Bucket — APPROVAL_OR_MINOR: Only Approval differs

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, RCV-IRV and Ranked Robin all agree on Brownie. Only Approval differs, electing Almond: Approval counts every score of 3–5 as one equal 'approve' and ignores intensity, rewarding Almond's breadth of acceptability over Brownie's stronger but more concentrated support. A threshold story about Approval, not a STAR-vs-IRV teaching case.

Winners by method

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

Flags: none

Source election: 01_STAR/02_Examples/runoff_overturns_leader/cases/01a_c3_b3_more-stars-fewer-voters.yaml · STAR tabulated mirror: 01a_c3_b3_more-stars-fewer-voters_tabulated.txt

3 candidates, 3 ballots.

The ballots

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

Count Almond Brownie Cocoa
1 5 1 2
2 4 5 0

STAR result (official)

Scoring round (sum of scores): Almond 13, Brownie 11, Cocoa 2

Finalists (top two): Almond and Brownie

Automatic runoff: Almond 1 vs Brownie 2

STAR winner: Brownie

Full LH STAR engine report:

--- Runoff (Preference) Matrix ---
Head-to-head / pairwise comparison
Legend: For - Equal Support - Against
        * indicates Top 2 Finalist
                |  * Almond   | * Brownie  |
--------------------------------------------
     * Almond > |     ---     | 1 - 0 - 2  |
    * Brownie > |  2 - 0 - 1  |    ---     |

[Divergence from STAR]
  STAR     = Brownie
  Approval = Almond   (differs from STAR)

[Runoff Reversal]
 - Score Round Winner(s) = (Almond)
 - Runoff Round Winner   = (Brownie)
  Candidate Almond earned the highest total score, but
  Candidate Brownie won the automatic runoff — not a malfunction,
  STAR working as designed: the runoff elects the finalist preferred
  by the majority (of voters with a preference).


--- STAR Voting Method (single winner) ---
 Tabulating 3 ballots.
Count × Almond,Brownie,Cocoa
    2 ×      4,      5,    0
    1 ×      5,      1,    2

[Score Distribution] (how many ballots gave each star rating)
                Score
Candidate  5  4  3  2  1  0  | Total   Avg
Almond     1  2  0  0  0  0  |    13   4.3
Brownie    2  0  0  0  1  0  |    11   3.7
Cocoa      0  0  0  1  0  2  |     2   0.7

Scoring Round
 The two highest-scoring candidates advance to the next round.
   Almond        -- 13 -- First place
   Brownie       -- 11 -- Second place
   Cocoa         --  2
 Almond and Brownie advance.

Automatic Runoff Round
 The candidate preferred in the most head-to-head matchups wins.
   Brownie       -- 2 -- First place
   Almond        -- 1
   Equal Support -- 0
 Brownie wins.
   Voters with a preference: 3 of 3 (no Equal Support).
   Brownie 2 (67%) vs Almond 1 (33%); majority = 2.

Winner — STAR Voting Method (single winner)
 Brownie

RCV-IRV — round by round

--- RCV / Instant-Runoff Voting (single winner) ---
 Tabulating 3 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: Almond, Brownie, Cocoa
     1 ×   Almond > Cocoa > Brownie      (5, 1, 2)
     2 ×   Brownie > Almond      (4, 5, 0)

FINAL RESULT
Candidate      Votes  Status
-----------  -------  --------
Brownie            2  Elected
Almond             1  Rejected
Cocoa              0  Rejected


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

--- 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): Brownie
   Outside (2):        Almond, Cocoa
   One member ⇒ Brownie is the Condorcet winner, beating every rival head-to-head.
   RCV-IRV winner Brownie is INSIDE the Smith set. ✓
      Not guaranteed — RCV-IRV is not Smith-efficient — but it holds here.
   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 3 ballots (score ballots).

Ballots:
   the ranking Ranked Robin reads ("=" = tied); source scores follow in () per column: Almond, Brownie, Cocoa
     1 × Almond > Cocoa > Brownie      (5, 1, 2)
     2 × Brownie > Almond > Cocoa      (4, 5, 0)

Round-Robin — every pair, head-to-head (For – Against):
   Brownie  beats Almond    2 – 1
   Almond   beats Cocoa     3 – 0
   Brownie  beats Cocoa     2 – 1

--- Pairwise (Round-Robin) Matrix ---
Head-to-head / pairwise comparison — the Ranked Robin tally
Legend: For - Equal Support - Against   (row vs column)
            |  Almond   | Brownie  |  Cocoa   |
-----------------------------------------------
   Almond > |    ---    |1 - 0 - 2 |3 - 0 - 0 |
  Brownie > | 2 - 0 - 1 |   ---    |2 - 0 - 1 |
    Cocoa > | 0 - 0 - 3 |1 - 0 - 2 |   ---    |

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  Brownie    2–0–0         2      +2  Almond, Cocoa
    2  Almond     1–1–0         1      +2  Cocoa
    3  Cocoa      0–2–0         0      -4  —

Winner — Ranked Robin (RCV-RR): Brownie
   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): Brownie
   Outside (2):        Almond, Cocoa
   One member ⇒ Brownie is the Condorcet winner, beating every rival head-to-head.
   Ranked Robin (RCV-RR) winner Brownie 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