Vote splitting — scenario 2 of 3 — no spoiler (bloc leader wins anyway)¶

Generated from vote_splitting_scenario2_bloc_leads.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: DarkChoco

Scenario¶

A split does NOT always cause a spoiler. If the bloc's larger half still out-polls the outsider, the bloc wins Choose-One regardless of the split.

36 voters. Chocolate = 24 (DarkChoco 14, MilkChoco 10); Vanilla 12.

Choose-One first choices: DarkChoco 14, Vanilla 12, MilkChoco 10. DarkChoco — a chocolate — already wins, so there is nothing for STAR to "fix" here.

The [Vote-splitting check] reports: the bloc's own front-runner also wins Choose-One overall, so no spoiler occurred.

Parameters (from the YAML)¶

blocs:
  Chocolate: [DarkChoco, MilkChoco]

Ballots¶

The ballots as marked — the filled bubble is the score given, and the score is the number in its column:

#	DarkChoco	MilkChoco	Vanilla
1	5	4	0
2	4	5	0
3	2	1	5

The same ballots as the file records them:

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

Count:DarkChoco,MilkChoco,Vanilla
14:5,4,0   # love dark, like milk, no vanilla
10:4,5,0   # love milk, like dark, no vanilla
12:2,1,5   # love vanilla, mild on chocolate

What the engine says¶

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

[Vote-splitting check]
  Choose-One first choices: DarkChoco 14, Vanilla 12, MilkChoco 10
  Plurality winner: DarkChoco (14, 38.9%)
  Bloc 'Chocolate' = DarkChoco, MilkChoco: combined 24 (66.7%); winner DarkChoco is INSIDE it.
  => No vote splitting: the bloc's own front-runner (DarkChoco) also wins
     Choose-One overall.

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

[STAR Voting]
 Tabulating 36 ballots.
Count × DarkChoco,MilkChoco,Vanilla
   14 ×         5,        4,      0
   12 ×         2,        1,      5
   10 ×         4,        5,      0

[STAR Voting: Scoring Round]
 The two highest-scoring candidates advance to the next round.
   DarkChoco     -- 134 -- First place
   MilkChoco     -- 118 -- Second place
   Vanilla       --  60
 DarkChoco and MilkChoco advance.

[STAR Voting: Automatic Runoff Round]
 The candidate preferred in the most head-to-head matchups wins.
   DarkChoco     -- 26 -- First place
   MilkChoco     -- 10
   Equal Support --  0
 DarkChoco wins.
   Runoff math:
     36  ballots cast
   −  0  Equal Support (no preference between the two finalists)
     ──
     36  voters with a preference  (majority = 19)
           DarkChoco 26 (72%)  ·  MilkChoco 10 (28%)

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

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
                  |  * DarkChoco  | * MilkChoco  |    Vanilla   |
-----------------------------------------------------------------
    * DarkChoco > |      ---      |26 -  0 - 10  |24 -  0 - 12  |
    * MilkChoco > | 10 -  0 - 26  |     ---      |24 -  0 - 12  |
        Vanilla > | 12 -  0 - 24  |12 -  0 - 24  |     ---      |

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

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

[Score Distribution] (how many ballots gave each star rating)
                   Score
Candidate   5   4   3   2   1   0  | Total   Avg
DarkChoco  14  10   0  12   0   0  |   134   3.7
MilkChoco  10  14   0   0  12   0  |   118   3.3
Vanilla    12   0   0   0   0  24  |    60   1.7

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/02_Examples/cases/vote_splitting_scenario2_bloc_leads.yaml