The Post-it RCV example (20 voters) — STAR: Blue wins the runoff RCV-IRV never held¶

Generated from bv2176_p8dp28_star.yaml — do not edit by hand. Regenerate: python STARVote_LH_tabulation_engine/tools_adam/scripts/build_yaml_pages.py.

Method: STAR (single winner) · 1 seat · Expected winner: Blue

▶ Live on BetterVoting: vote · results ↗ (election p8dp28 · test BV2176).

Scenario¶

One of three races in the Post-it RCV example (BV2176, bvid p8dp28; BV-confirmed). The 20-voter election from Equal Vote's video "Updated: How does RCV work? — With Post-its!" (https://youtu.be/Vte4nly_Neg), using the video's own 0-5 scores from the same voters whose ranked ballots it walks through. Scoring round: Purple 46, Blue 44, Pink 44, Green 38 — Purple advances, and the 44-44 tie for the second finalist breaks head-to-head (Blue is preferred over Pink 10-3). Automatic runoff: Blue beats Purple 10-9 (1 Equal Support) — a Runoff Reversal (the score leader loses the majority check), and it is exactly the 10-9 majority the video surfaces in its "what if Green had been eliminated instead of Blue?" hypothetical. RCV-IRV on these voters' ranked ballots elects Purple without ever holding that matchup (see the companion race). BetterVoting agrees: Blue, with tieBreakType head_to_head on the scoring tie.

Live results: https://bettervoting.com/p8dp28/results Companion races: bv2176_p8dp28_irv.yaml, bv2176_p8dp28_ranked_robin.yaml. Overview page: bv2176_p8dp28_postit_rcv_example.md

Ballots¶

Row 1 = candidate names; each later row is one voter's 0–5 scores (a N × prefix = N identical ballots).

Purple,Green,Blue,Pink
5,0,0,0
5,0,0,0
5,0,0,0
5,0,0,0
5,0,0,0
5,0,0,0
5,0,0,0
0,5,4,3
0,5,4,3
0,5,4,3
0,5,4,3
0,5,4,3
0,5,4,3
0,0,5,4
0,0,5,4
0,4,5,3
4,0,5,0
3,4,0,5
4,0,0,5
0,0,0,5

What the engine says¶

The count, step by step — the rounds and how the winner is reached:

[Divergence from STAR]
  STAR                   = Blue
  Choose-One (Plurality) = Purple   (differs from STAR)
  RCV-IRV                = Purple   (differs from STAR)
  Approval               = Pink   (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/bv2176_p8dp28_star_RCV-IRV_tabulated.txt

[Runoff Reversal]
 - Score Round Winner(s) = (Purple)
 - Runoff Round Winner   = (Blue)
  Candidate Purple earned the highest total score, but
  Candidate Blue 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) ---

[STAR Voting]
 Tabulating 20 ballots.
Count × Purple,Green,Blue,Pink
    7 ×      5,    0,   0,   0
    6 ×      0,    5,   4,   3
    2 ×      0,    0,   5,   4
    1 ×      0,    4,   5,   3
    1 ×      4,    0,   5,   0
    1 ×      3,    4,   0,   5
    1 ×      4,    0,   0,   5
    1 ×      0,    0,   0,   5

[STAR Voting: Scoring Round]
 The two highest-scoring candidates advance to the next round.
   Purple        -- 46 -- First place
   Blue          -- 44 -- Tied for second place
   Pink          -- 44 -- Tied for second place
   Green         -- 38
 Purple advances, but there's a two-way tie for second.

[STAR Voting: Scoring Round: First tiebreaker]
 The candidate preferred in the most head-to-head matchups advances.
   Blue          -- 10 -- Second place
   Pink          --  3
   Equal Support --  7
 Purple and Blue advance.

[STAR Voting: Automatic Runoff Round]
 The candidate preferred in the most head-to-head matchups wins.
   Blue          -- 10 -- First place
   Purple        --  9
   Equal Support --  1
 Blue wins.
   Runoff math:
     20  ballots cast
   −  1  Equal Support (no preference between the two finalists)
     ──
     19  voters with a preference  (majority = 10)
           Blue 10 (53%)  ·  Purple 9 (47%)

[STAR Voting: Winner — STAR Voting Method (single winner)]
 Blue

Full audit — preference matrix, Condorcet, and score distribution¶

--- Runoff (Preference) Matrix ---
Head-to-head / pairwise comparison
Legend: For - Equal Support - Against
        * indicates Top 2 Finalist
        Note: Blue and Pink tied at 44 in the Scoring Round, and the
              head-to-head rung advanced Blue. The * marks who advanced, not
              who scored highest.

                 |   * Purple   |    Green    |   * Blue    |     Pink    |
---------------------------------------------------------------------------
      * Purple > |     ---      | 9 -  3 -  8 | 9 -  1 - 10 | 8 -  0 - 12 |
         Green > |  8 -  3 -  9 |    ---      | 7 -  9 -  4 | 7 -  8 -  5 |
        * Blue > | 10 -  1 -  9 | 4 -  9 -  7 |    ---      |10 -  7 -  3 |
          Pink > | 12 -  0 -  8 | 5 -  8 -  7 | 3 -  7 - 10 |    ---      |

[Condorcet Winner]
  No Condorcet winner (majority cycle: Purple > Green > Blue > Pink > Purple)

[Score Distribution] (how many ballots gave each star rating)
                   Score
Candidate   5   4   3   2   1   0  | Total   Avg
Purple      7   2   1   0   0  10  |    46   2.3
Green       6   2   0   0   0  12  |    38   1.9
Blue        4   6   0   0   0  10  |    44   2.2
Pink        3   2   7   0   0   8  |    44   2.2

Everything in one file: the _tabulated mirror (regenerated on every run; every analysis forced on).

Run it yourself:

python STARVote_LH_tabulation_engine/starvote_larry_hastings.py method_comparisons/postit_rcv_example/cases/bv2176_p8dp28_star.yaml

The Post-it RCV example (20 voters) — STAR: Blue wins the runoff RCV-IRV never held¶

Scenario¶

Ballots¶

What the engine says¶

Full audit — preference matrix, Condorcet, and score distribution¶

See also¶