Vote splitting — scenario 3 of 3 — no spoiler (the outsider truly wins)¶

Generated from vote_splitting_scenario3_outsider_wins.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: Vanilla

Scenario¶

When the outsider is the genuine favorite, there is no spoiler — uniting the bloc would not change the result.

62 voters. Vanilla 40, DarkChoco 12, MilkChoco 10. Chocolate combined is only 22, far short of Vanilla's 40.

Choose-One first choices: Vanilla 40, DarkChoco 12, MilkChoco 10. Vanilla wins — and would still win even if the two chocolates merged into one (22 < 40). STAR also elects Vanilla. Fair and square.

The [Vote-splitting check] reports: even combined, the bloc does not out-poll the winner, 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	1	0	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
12:5,4,0   # love dark, like milk, no vanilla
10:4,5,0   # love milk, like dark, no vanilla
40:1,0,5   # 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: Vanilla 40, DarkChoco 12, MilkChoco 10
  Plurality winner: Vanilla (40, 64.5%)
  Bloc 'Chocolate' = DarkChoco, MilkChoco: combined 22 (35.5%); winner Vanilla is OUTSIDE it.
  => No vote splitting: even combined (22), the 'Chocolate' bloc does not
     outpoll Vanilla (40).

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

[STAR Voting]
 Tabulating 62 ballots.
Count × DarkChoco,MilkChoco,Vanilla
   40 ×         1,        0,      5
   12 ×         5,        4,      0
   10 ×         4,        5,      0

[STAR Voting: Scoring Round]
 The two highest-scoring candidates advance to the next round.
   Vanilla       -- 200 -- First place
   DarkChoco     -- 140 -- Second place
   MilkChoco     --  98
 Vanilla and DarkChoco advance.

[STAR Voting: Automatic Runoff Round]
 The candidate preferred in the most head-to-head matchups wins.
   Vanilla       -- 40 -- First place
   DarkChoco     -- 22
   Equal Support --  0
 Vanilla wins.
   Runoff math:
     62  ballots cast
   −  0  Equal Support (no preference between the two finalists)
     ──
     62  voters with a preference  (majority = 32)
           Vanilla 40 (65%)  ·  DarkChoco 22 (35%)

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

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 > |      ---      |52 -  0 - 10  |22 -  0 - 40  |
      MilkChoco > | 10 -  0 - 52  |     ---      |22 -  0 - 40  |
      * Vanilla > | 40 -  0 - 22  |40 -  0 - 22  |     ---      |

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

[Condorcet Loser]
  Condorcet Loser: MilkChoco — 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  12  10   0   0  40   0  |   140   2.3
MilkChoco  10  12   0   0   0  40  |    98   1.6
Vanilla    40   0   0   0   0  22  |   200   3.2

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 01_STAR/02_Examples/cases/vote_splitting_scenario3_outsider_wins.yaml