STAR mono-raise-delete — part 2: raise X, delete Y-below-X, X loses¶

Generated from mono_raise_delete_after.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: Z

Scenario¶

Part 2 of the STAR mono-raise-delete pair. The ONLY change from part 1 (mono_raise_delete_before.yaml): on the nine ballots that read Z>X>Y (Z=5, X=3, Y=2, i.e. "3,2,5"), X is raised from 3 to 4 and the one candidate now below X — Y — is deleted (dropped to 0). Those ballots become Z=5, X=4, Y=0 ("4,0,5"). Z stays above X and is untouched, exactly as mono-raise-delete prescribes ("delete all candidates now below X").

Effect: burying Y drops its total from 84 to 66, below Z's 72, so the finalists change from {X, Y} to {X, Z}. X still leads the scoring round (now 96), but the runoff is X vs Z, and Z beats X 18-12. X went from winning to losing after being raised — STAR fails the mono-raise-delete criterion (Woodall 1996). It still passes plain mono-raise (see the monotonicity_star_* pair, where the same kind of change leaves X winning). Concept: 01_STAR/01_Learn/properties_and_limits/STAR_monotonicity.md.

Ballots¶

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

X,Y,Z
12: 5,4,0
9: 4,0,5
9: 0,2,3

What the engine says¶

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

[Divergence from STAR]
  STAR     = Z
  Approval = X   (differs from STAR)

[Runoff Reversal]
 - Score Round Winner(s) = (X)
 - Runoff Round Winner   = (Z)
  Candidate X earned the highest total score, but
  Candidate Z 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 30 ballots.
Count × X,Y,Z
   12 × 5,4,0
    9 × 4,0,5
    9 × 0,2,3

[STAR Voting: Scoring Round]
 The two highest-scoring candidates advance to the next round.
   X             -- 96 -- First place
   Z             -- 72 -- Second place
   Y             -- 66
 X and Z advance.

[STAR Voting: Automatic Runoff Round]
 The candidate preferred in the most head-to-head matchups wins.
   Z             -- 18 -- First place
   X             -- 12
   Equal Support --  0
 Z wins.
   Runoff math:
     30  ballots cast
   −  0  Equal Support (no preference between the two finalists)
     ──
     30  voters with a preference  (majority = 16)
           Z 18 (60%)  ·  X 12 (40%)

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

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
                 |     * X      |      Y      |    * Z      |
-------------------------------------------------------------
           * X > |     ---      |21 -  0 -  9 |12 -  0 - 18 |
             Y > |  9 -  0 - 21 |    ---      |12 -  0 - 18 |
           * Z > | 18 -  0 - 12 |18 -  0 - 12 |    ---      |

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

[Condorcet Loser]
  Condorcet Loser: Y — 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
X          12   9   0   0   0   9  |    96   3.2
Y           0  12   0   9   0   9  |    66   2.2
Z           9   0   9   0   0  12  |    72   2.4

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/monotonicity/cases/mono_raise_delete_after.yaml

STAR mono-raise-delete — part 2: raise X, delete Y-below-X, X loses¶

Scenario¶

Ballots¶

What the engine says¶

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

See also¶