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Ice cream ladder — a STAR tie in both rounds, settled without the lot (BV2180, fp62p2)

▶ Live on BetterVoting: vote · results ↗ (election fp62p2 · test BV2180) — an independent tabulator to check the winners below against.

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

Winners by method

Method Winner
STAR Strawberry
RCV-IRV Strawberry
Ranked Robin (RCV-RR) Strawberry
Approval Chocolate
Range / Score Strawberry
Condorcet none (cycle)

Flags: 2 tied-score ballot(s)

Source election: 01_STAR/03_Criteria/tie_break_ladder/cases/bv2180_fp62p2_ice_cream_ladder.yaml · STAR tabulated mirror: bv2180_fp62p2_ice_cream_ladder_tabulated.txt

6 candidates, 2 ballots.

The ballots

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

Count Chocolate Chocolate Chip Fudge Brownie Vanilla Strawberry Mango
1 4 5 4 1 2 0
1 1 0 0 4 5 4

STAR result (official)

Scoring round (sum of scores): Strawberry 7, Chocolate 5, Chocolate Chip 5, Vanilla 5, Fudge Brownie 4, Mango 4

Finalists (top two): Strawberry and Chocolate

Automatic runoff: Strawberry 1 vs Chocolate 1

STAR winner: Chocolate

Full LH STAR engine report:

--- Runoff (Preference) Matrix ---
Head-to-head / pairwise comparison
Legend: For - Equal Support - Against
        * indicates Top 2 Finalist
        Note: Chocolate, Chocolate Chip and Vanilla tied at 5 in the Scoring
              Round, and the five-star rung advanced Chocolate Chip. The *
              marks who advanced, not who scored highest. Chocolate and
              Vanilla are filtered out of this grid — see the Scoring Round
              for how the tie was settled.

                       |  * Chocolate Chip  |   * Strawberry    |
-----------------------------------------------------------------
    * Chocolate Chip > |        ---         |    1 - 0 - 1      |
        * Strawberry > |     1 - 0 - 1      |       ---         |

[Divergence from STAR]
  STAR                   = Strawberry
  Choose-One (Plurality) = Chocolate Chip   (differs from STAR)
  Approval               = Chocolate   (differs from STAR)

--- STAR Voting Method (single winner) ---
 Tabulating 2 ballots.
Chocolate,Chocolate Chip,Fudge Brownie,Vanilla,Strawberry,Mango
        4,             5,            4,      1,         2,    -
        1,             0,            0,      4,         5,    4
  ('-' = left blank / abstained; '0' = scored zero — both count as 0 stars.)

[Score Distribution] (how many ballots gave each star rating)
                     Score
Candidate       5  4  3  2  1  0  Abs  | Total  Avg all  Avg rated
Chocolate       0  1  0  0  1  0    0  |     5      2.5        2.5
Chocolate Chip  1  0  0  0  0  1    0  |     5      2.5        2.5
Fudge Brownie   0  1  0  0  0  1    0  |     4      2.0        2.0
Vanilla         0  1  0  0  1  0    0  |     5      2.5        2.5
Strawberry      1  0  0  1  0  0    0  |     7      3.5        3.5
Mango           0  1  0  0  0  0    1  |     4      2.0        4.0
  Avg all   = Total / all ballots — a blank counts as 0, so this is the Total the Scoring Round ranks on, per ballot.
  Avg rated = Total / the ballots that scored this candidate (Abs excluded) — support among voters who had an opinion.

Scoring Round
 The two highest-scoring candidates advance to the next round.
   Strawberry     -- 7 -- First place
   Chocolate      -- 5 -- Tied for second place
   Chocolate Chip -- 5 -- Tied for second place
   Vanilla        -- 5 -- Tied for second place
   Fudge Brownie  -- 4
   Mango          -- 4
 Strawberry advances, but there's a three-way tie for second.

Scoring Round: First tiebreaker
 The candidate preferred in the most head-to-head matchups advances.
   Chocolate      -- 2 -- Tied for second place
   Chocolate Chip -- 2 -- Tied for second place
   Vanilla        -- 2 -- Tied for second place
   Equal Support  -- 0
 There's still a three-way tie for second.

Scoring Round: Second tiebreaker
 The candidate with the most votes of score 5 advances.
   Chocolate Chip -- 1 -- Second place
   Chocolate      -- 0
   Vanilla        -- 0
 Strawberry and Chocolate Chip advance.

Automatic Runoff Round
 The candidate preferred in the most head-to-head matchups wins.
   Chocolate Chip -- 1 -- Tied for first place
   Strawberry     -- 1 -- Tied for first place
   Equal Support  -- 0
 There's a two-way tie for first.

Automatic Runoff Round: First tiebreaker
 The highest-scoring candidate wins.
   Strawberry     -- 7 -- First place
   Chocolate Chip -- 5
 Strawberry wins.

Winner — STAR Voting Method (single winner)
 Strawberry

RCV-IRV — round by round

--- RCV / Instant-Runoff Voting (single winner) ---
 Tabulating 2 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: Chocolate, Chocolate Chip, Fudge Brownie, Vanilla, Strawberry, Mango
     1 ×   Chocolate Chip > Chocolate > Fudge Brownie > Strawberry > Vanilla      (4, 5, 4, 1, 2, 0)
     1 ×   Strawberry > Vanilla > Mango > Chocolate      (1, 0, 0, 4, 5, 4)

FINAL RESULT
Candidate         Votes  Status
--------------  -------  --------
Strawberry            1  Elected
Chocolate Chip        1  Rejected
Chocolate             0  Rejected
Vanilla               0  Rejected
Fudge Brownie         0  Rejected
Mango                 0  Rejected


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

--- 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 (6 of 6): Strawberry, Chocolate, Chocolate Chip, Vanilla, Fudge Brownie, Mango
   Outside (0):        —
   More than one member ⇒ NO Condorcet winner: the top of the tournament is a
   group held open by draws, so the strongest "candidate" is a set, not a
   person. Some members DO beat others, but no member beats them all — a draw
   blocks the sweep. No loop closes either, so there is no cycle for Minimax /
   Ranked Pairs / Schulze to resolve: which member wins is left to the
   tiebreak, not to a cycle rule. See
   05_Ranked_Robin/01_Learn/rr_tiebreak_lh_vs_bv.md.
   Note: the Copeland leaders (Strawberry) are only part of the set — the
   win–loss table's top block understates how wide the contention is.
   RCV-IRV winner Strawberry is INSIDE the Smith set. ✓
      Not guaranteed — RCV-IRV is not Smith-efficient — but it holds here.
   Fine print: this set contains a pairwise DRAW, and a draw is enough to keep a
   candidate in the Smith set but not in the tighter Schwartz set — so Schwartz
   may be smaller 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 2 ballots (score ballots).

Ballots:
   the ranking Ranked Robin reads ("=" = tied); source scores follow in () per column: Chocolate, Chocolate Chip, Fudge Brownie, Vanilla, Strawberry, Mango
     1 × Chocolate Chip > Chocolate=Fudge Brownie > Strawberry > Vanilla > Mango      (4, 5, 4, 1, 2, 0)
     1 × Strawberry > Vanilla=Mango > Chocolate > Chocolate Chip=Fudge Brownie      (1, 0, 0, 4, 5, 4)

Round-Robin — every pair, head-to-head (For – Against):
   Chocolate       ties  Chocolate Chip   1 – 1
   Chocolate       beats Fudge Brownie    1 – 0
   Chocolate       ties  Vanilla          1 – 1
   Chocolate       ties  Strawberry       1 – 1
   Chocolate       ties  Mango            1 – 1
   Chocolate Chip  beats Fudge Brownie    1 – 0
   Chocolate Chip  ties  Vanilla          1 – 1
   Chocolate Chip  ties  Strawberry       1 – 1
   Chocolate Chip  ties  Mango            1 – 1
   Fudge Brownie   ties  Vanilla          1 – 1
   Fudge Brownie   ties  Strawberry       1 – 1
   Fudge Brownie   ties  Mango            1 – 1
   Strawberry      beats Vanilla          2 – 0
   Vanilla         beats Mango            1 – 0
   Strawberry      beats Mango            2 – 0

--- Pairwise (Round-Robin) Matrix ---
Head-to-head / pairwise comparison — the Ranked Robin tally
Legend: For - Equal Support - Against   (row vs column)
                   |    Chocolate     | Chocolate Chip  | Fudge Brownie   |    Vanilla      |   Strawberry    |     Mango       |
---------------------------------------------------------------------------------------------------------------------------------
       Chocolate > |       ---        |   1 - 0 - 1     |   1 - 1 - 0     |   1 - 0 - 1     |   1 - 0 - 1     |   1 - 0 - 1     |
  Chocolate Chip > |    1 - 0 - 1     |      ---        |   1 - 1 - 0     |   1 - 0 - 1     |   1 - 0 - 1     |   1 - 0 - 1     |
   Fudge Brownie > |    0 - 1 - 1     |   0 - 1 - 1     |      ---        |   1 - 0 - 1     |   1 - 0 - 1     |   1 - 0 - 1     |
         Vanilla > |    1 - 0 - 1     |   1 - 0 - 1     |   1 - 0 - 1     |      ---        |   0 - 0 - 2     |   1 - 1 - 0     |
      Strawberry > |    1 - 0 - 1     |   1 - 0 - 1     |   1 - 0 - 1     |   2 - 0 - 0     |      ---        |   2 - 0 - 0     |
           Mango > |    1 - 0 - 1     |   1 - 0 - 1     |   1 - 0 - 1     |   0 - 1 - 1     |   0 - 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  Strawberry      2–0–3       3.5      +4  Vanilla, Mango
    2  Chocolate       1–0–4         3      +1  Fudge Brownie
    3  Chocolate Chip  1–0–4         3      +1  Fudge Brownie
    4  Vanilla         1–1–3       2.5      -1  Mango
    5  Fudge Brownie   0–2–3       1.5      -2  —
    6  Mango           0–2–3       1.5      -3  —

Winner — Ranked Robin (RCV-RR): Strawberry
   unbeaten, but draws Chocolate, Chocolate Chip, Fudge Brownie — a *weak* Condorcet winner, not a strict one (highest Copeland score, 3.5).

--- 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 (6 of 6): Strawberry, Chocolate, Chocolate Chip, Vanilla, Fudge Brownie, Mango
   Outside (0):        —
   More than one member ⇒ NO Condorcet winner: the top of the tournament is a
   group held open by draws, so the strongest "candidate" is a set, not a
   person. Some members DO beat others, but no member beats them all — a draw
   blocks the sweep. No loop closes either, so there is no cycle for Minimax /
   Ranked Pairs / Schulze to resolve: which member wins is left to the
   tiebreak, not to a cycle rule. See
   05_Ranked_Robin/01_Learn/rr_tiebreak_lh_vs_bv.md.
   Note: the Copeland leaders (Strawberry) are only part of the set — the
   win–loss table's top block understates how wide the contention is.
   Ranked Robin (RCV-RR) winner Strawberry 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.
   Fine print: this set contains a pairwise DRAW, and a draw is enough to keep a
   candidate in the Smith set but not in the tighter Schwartz set — so Schwartz
   may be smaller here.
   More: 07_Concepts/topics/smith_set.md