Center Squeeze — IRV (Hare): the center gets squeezed out¶

Generated from bv2137_ywckmg_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: Carter

▶ Live on BetterVoting: vote · results ↗ (election ywckmg · test BV2137).

Scenario¶

One of four races in the Center Squeeze election (BV2137, bvid ywckmg; BV-confirmed). 100 voters, three candidates, ONE ranked electorate tabulated four ways. Anderson is the Condorcet winner (beats Reagan 55–45, Carter 65–35) but holds the fewest first-choices (20). IRV eliminates the low-first-choice centrist Anderson FIRST, then Carter beats Reagan 55–45. IRV → Carter, NOT the Condorcet winner.

Ballots¶

Each row is one voter's ranking, most-preferred first (N: prefix = N identical ballots).

45:Reagan>Anderson>Carter
20:Anderson>Carter>Reagan
35:Carter>Anderson>Reagan

What the engine says¶

Round-by-round Sankey diagram: each candidate's votes as a band, and where the votes of an eliminated candidate transferred to.

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) ---
  Center Squeeze — IRV (Hare): the center gets squeezed out
 Tabulating 100 ballots (ranked ballots).

ROUND 1
Candidate      Votes  Status
-----------  -------  --------
Reagan            45  Hopeful
Carter            35  Hopeful
Anderson          20  Rejected

FINAL RESULT
Candidate      Votes  Status
-----------  -------  --------
Carter            55  Elected
Reagan            45  Rejected
Anderson           0  Rejected


Winner(s) — RCV / Instant-Runoff Voting (single winner)
  Carter

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 3): Anderson
   Outside (2):        Reagan, Carter
   One member ⇒ Anderson is the Condorcet winner, beating every rival head-to-head.
   RCV-IRV winner Carter is OUTSIDE the Smith set. ✗
      Every member of the set (Anderson) beats Carter head-to-head, yet
      RCV-IRV elected Carter 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/center_squeeze_bv2137/cases/bv2137_ywckmg_irv.yaml

Center Squeeze — IRV (Hare): the center gets squeezed out¶

Scenario¶

Ballots¶

What the engine says¶

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

See also¶