BV2133 — Pet poll II (RCV-IRV): transfers elect Fish¶
Generated from bv2133_dyxrbr_pet2_irv.yaml — do not edit by hand. Regenerate: python STARVote_LH_tabulation_engine/tools_adam/scripts/build_yaml_pages.py.
Method: RCV-IRV (Instant Runoff) · 1 seat · Expected winner: Fish
▶ Live on BetterVoting: vote · results ↗ (election dyxrbr · test BV2133).
Scenario¶
One of four races in the BV2133 "Pet poll II" (BetterVoting election dyxrbr). RCV-IRV (ranked, instant runoff). Round 1: Dog 13, Fish 10, Bird 9 — eliminate Bird; Bird > Cat, so Cat rises. Then Cat (fewest) is eliminated and its ballots flow to Fish, which beats Dog 19-13. So IRV elects Fish. Same electorate as the Plurality race (Dog), Approval race (Bird) and STAR race (Cat): four methods, four winners. BV also elects Fish. Live results: https://bettervoting.com/dyxrbr/results
Ballots¶
Each row is one voter's ranking, most-preferred first (N: prefix = N identical ballots).
9:Bird>Cat>Fish>Dog
10:Fish>Cat>Bird>Dog
13:Dog>Cat>Fish>Bird
What the engine says¶
Where the votes went. Band thickness is votes; a band leaving an eliminated candidate lands on whoever that ballot ranked next, or on inactive if it ranked nobody who was left.
The count, step by step — the rounds and how the winner is reached:
--- RCV / Instant-Runoff Voting (single winner) ---
BV2133 — Pet poll II (RCV-IRV): transfers elect Fish
Tabulating 32 ballots (ranked ballots).
ROUND 1
Candidate Votes Status
----------- ------- --------
Dog 13 Hopeful
Fish 10 Hopeful
Bird 9 Rejected
Cat 0 Rejected
FINAL RESULT
Candidate Votes Status
----------- ------- --------
Fish 19 Elected
Dog 13 Rejected
Bird 0 Rejected
Cat 0 Rejected
Winner(s) — RCV / Instant-Runoff Voting (single winner)
Fish
--- Transfers and inactive ballots (what the round tables leave out) ---
The tables above give each candidate's round total but not where a
transferred vote came FROM, nor how many ballots stopped counting.
Both are recomputed from the ballots, using the eliminations the
count above actually made.
ROUND 1 — 32 of 32 ballots still active; majority = 17
Cat eliminated with 0:
→ (held no ballots)
Bird eliminated with 9:
→ Fish 9
FINAL ROUND — 32 of 32 ballots still active; majority = 17
Fish 19 (59.4% of the still-active) ← elected
Dog 13 (40.6% of the still-active)
Never exhausted, never transferred:
13 ballots held by Dog carried a lower ranking that was never read
(the count stopped here, so those preferences did nothing).
Inactive ballots at the final round: 0 of 32 (0.0%).
Fish's 19 is a majority of the 32 still active AND of all 32 cast (59.4%).
Full audit — preference matrix, Condorcet, and score distribution¶
--- Smith Set (the generalized Condorcet winner) ---
The smallest group whose every member beats every candidate outside it —
the honest answer to "who is even in contention?".
Smith set (1 of 4): Cat
Outside (3): Bird, Fish, Dog
One member ⇒ Cat is the Condorcet winner, beating every rival head-to-head.
RCV-IRV winner Fish is OUTSIDE the Smith set. ✗
Every member of the set (Cat) beats Fish head-to-head, yet
RCV-IRV elected Fish anyway. RCV-IRV is not Smith-efficient (nor
Condorcet-efficient) — this is the shape a center squeeze leaves behind.
More: 07_Concepts/topics/smith_set.md
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/pet_poll_four_winners/cases/bv2133_dyxrbr_pet2_irv.yaml
See also¶
More cases in this set: bv2133_dyxrbr_pet2_approval · bv2133_dyxrbr_pet2_plurality · bv2133_dyxrbr_pet2_star