Exercise 7 — The vanishing votes that never vanished (a park-tree ballot drill)¶

Generated from ex07_vanishing_votes.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: Aspen

Scenario¶

A park board picks a tree. Nine ballot papers come back: two score the finalists equal at the top (5-5), one at 3-3, one bullet-votes Cedar (0,0,5), one is all zeros, one is completely blank — and only three express a preference between the finalists Aspen and Birch. The drill: predict every number in the two-line runoff summary before peeking. Scoring round: Aspen 24, Birch 20, Cedar 13. Runoff: Aspen 2, Birch 1, Equal Support 6 — "Voters with a preference: 3 of 9 (6 Equal Support)". The 9 counts every tabulated ballot: the blank abstention folds into Equal Support on this line, and the separate engine Note ("1 of 9 ballots is marked as an abstention") carries the cast-vs-abstained split. No vote vanished: equal scores are counted in full in the scoring round and then have no preference to give between equals. Exercise: ex07_vanishing_votes.md. Ballots and cast are this repo's own.

Ballots¶

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

Markers on these ballots: - blank · ~ race abstention · & candidate abstention · ? spoiled · % spoiled+reissued — all tabulate as 0 (reported honestly).

Aspen,Birch,Cedar
5,5,0 # equal top pair — full weight in scoring, Equal Support in the runoff
5,5,3 # same, with a nod to Cedar
3,3,5 # Cedar first — and equal on the two finalists
5,2,0 # a clear Aspen preference
4,1,0 # a clear Aspen preference
2,4,0 # a clear Birch preference
0,0,5 # bullet vote for Cedar — zero on both finalists is still Equal Support
0,0,0 # all zeros — a CAST ballot that supports no one
-,-,- # completely blank — a true abstention, not a cast ballot

What the engine says¶

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

--- STAR Voting Method (single winner) ---

[STAR Voting]
 Tabulating 9 ballots. Note: 1 of 9 ballots is marked as an abstention.
Aspen,Birch,Cedar
    5,    5,    0
    5,    5,    3
    3,    3,    5
    5,    2,    0
    4,    1,    0
    2,    4,    0
    0,    0,    5
    0,    0,    0
    -,    -,    -
  ('-' = left blank / abstained; '0' = scored zero — both count as 0 stars.)

[STAR Voting: Scoring Round]
 The two highest-scoring candidates advance to the next round.
   Aspen         -- 24 -- First place
   Birch         -- 20 -- Second place
   Cedar         -- 13
 Aspen and Birch advance.

[STAR Voting: Automatic Runoff Round]
 The candidate preferred in the most head-to-head matchups wins.
   Aspen         -- 2 -- First place
   Birch         -- 1
   Equal Support -- 6
 Aspen wins.
   Runoff math:
     9  ballots cast
   − 6  Equal Support (no preference between the two finalists)
     ─
     3  voters with a preference  (majority = 2)
           Aspen 2 (67%)  ·  Birch 1 (33%)

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

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
               |  * Aspen   | * Birch   |   Cedar   |
-----------------------------------------------------
     * Aspen > |    ---     |2 - 6 - 1  |5 - 2 - 2  |
     * Birch > | 1 - 6 - 2  |   ---     |5 - 2 - 2  |
       Cedar > | 2 - 2 - 5  |2 - 2 - 5  |   ---     |

[Condorcet Winner]
  Condorcet Winner: Aspen — matches the STAR winner

[Condorcet Loser]
  Condorcet Loser: Cedar — loses every head-to-head matchup

[Score Distribution] (how many ballots gave each star rating)
                Score
Candidate  5  4  3  2  1  0  Abs  | Total  Avg all  Avg rated
Aspen      3  1  1  1  0  2    1  |    24      2.7        3.0
Birch      2  1  1  1  1  2    1  |    20      2.2        2.5
Cedar      2  0  1  0  0  5    1  |    13      1.4        1.6
  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.

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 01_STAR/05_Practice/cases/ex07_vanishing_votes.yaml

Exercise 7 — The vanishing votes that never vanished (a park-tree ballot drill)¶

Scenario¶

Ballots¶

What the engine says¶

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

See also¶