Exercise 10 — Later-no-harm: the generous ballots¶

Generated from ex10_generous.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: Bess

▶ Live on BetterVoting: vote · results ↗ (election yyhj9x · test BV2196).

Scenario¶

The same nine voters as ex10_reticent.yaml, but Amir's four fans now score honestly: Amir 5, Bess 3, Cato 0 — they genuinely like Bess second. Those twelve extra points lift Bess from 13 to 25: scoring round Bess 25, Amir 24, Cato 15 — and Bess beats Amir in the runoff 5-4. The fans' generosity cost their favorite the win: a LATER-NO-HARM failure, live. The counter-reading: Bess is this electorate's Condorcet winner (beats Amir 5-4, Cato 6-3) and is scored 1+ by all nine voters — the reticent ballots didn't protect Amir so much as HIDE Bess. STAR gives up later-no-harm on purpose: protecting favorites by hiding compromises is exactly what it declines to reward. Exercise: ex10_later_no_harm.md. Ballots and cast are this repo's own. Live on BetterVoting (Test ID BV2196): https://bettervoting.com/yyhj9x/results — with an RCV-IRV race (still Amir: IRV keeps later-no-harm precisely by center-squeezing the Condorcet winner Bess).

Ballots¶

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

Amir,Bess,Cato
5,3,0 # 4 voters: Amir fans, honest about liking Bess second
5,3,0
5,3,0
5,3,0
2,5,0 # 2 voters: Bess first, mild nod to Amir — unchanged
2,5,0
0,1,5 # 3 voters: Cato first, a token point to Bess — unchanged
0,1,5
0,1,5

What the engine says¶

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

[Divergence from STAR]
  STAR                   = Bess
  Choose-One (Plurality) = Amir   (differs from STAR)
  RCV-IRV                = Amir   (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/ex10_generous_RCV-IRV_tabulated.txt

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

[STAR Voting]
 Tabulating 9 ballots.
Count × Amir,Bess,Cato
    4 ×    5,   3,   0
    3 ×    0,   1,   5
    2 ×    2,   5,   0

[STAR Voting: Scoring Round]
 The two highest-scoring candidates advance to the next round.
   Bess          -- 25 -- First place
   Amir          -- 24 -- Second place
   Cato          -- 15
 Bess and Amir advance.

[STAR Voting: Automatic Runoff Round]
 The candidate preferred in the most head-to-head matchups wins.
   Bess          -- 5 -- First place
   Amir          -- 4
   Equal Support -- 0
 Bess wins.
   Runoff math:
     9  ballots cast
   − 0  Equal Support (no preference between the two finalists)
     ─
     9  voters with a preference  (majority = 5)
           Bess 5 (56%)  ·  Amir 4 (44%)

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

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
               |   * Amir   |  * Bess   |    Cato   |
-----------------------------------------------------
      * Amir > |    ---     |4 - 0 - 5  |6 - 0 - 3  |
      * Bess > | 5 - 0 - 4  |   ---     |6 - 0 - 3  |
        Cato > | 3 - 0 - 6  |3 - 0 - 6  |   ---     |

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

[Condorcet Loser]
  Condorcet Loser: Cato — 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
Amir       4  0  0  2  0  3  |    24   2.7
Bess       2  0  4  0  3  0  |    25   2.8
Cato       3  0  0  0  0  6  |    15   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/05_Practice/cases/ex10_generous.yaml

Exercise 10 — Later-no-harm: the generous ballots¶

Scenario¶

Ballots¶

What the engine says¶

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

See also¶