The Post-it switch, made real — RCV-IRV: Green eliminated, Blue 10, Purple 9¶

Generated from bv2178_8kg698_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: Blue

▶ Live on BetterVoting: vote · results ↗ (election 8kg698 · test BV2178).

Scenario¶

One of four races in the Post-it switch election (BV2178, bvid 8kg698; BV-confirmed). Equal Vote's video "Updated: How does RCV work? — With Post-its!" (https://youtu.be/Vte4nly_Neg) asks: what if round 2 had eliminated Green instead of Blue? Its answer — Blue jumps to 10 and wins 10-9 — is a hypothetical RCV-IRV itself would never execute (Green held 7 votes to Blue's 4). This election makes it REAL with the smallest possible nudge: two of the six Green>Blue>Pink voters genuinely prefer Blue first (Blue>Green>Pink). Now round 1 is Purple 7, Blue 6, Green 4, Pink 3; round 2 Purple 8, Blue 6, Green 5 — GREEN is eliminated, all four remaining Green>Blue>Pink ballots transfer to Blue, and the final is the video's exact hypothetical tally: Blue 10, Purple 9 (1 exhausted). Two ballots moved; the winner flipped from Purple to Blue — RCV-IRV finds Blue's head-to-head strength only when Blue's supporters put Blue FIRST. See the fairness lesson page: postit_video_fair_and_balanced.md.

Live results: https://bettervoting.com/8kg698/results Companion races: bv2178_8kg698_star.yaml, bv2178_8kg698_ranked_robin.yaml. Overview page: bv2178_8kg698_switch_made_real.md

Ballots¶

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

Purple
Purple
Purple
Purple
Purple
Purple
Purple
Green>Blue>Pink
Green>Blue>Pink
Green>Blue>Pink
Green>Blue>Pink
Blue>Green>Pink
Blue>Green>Pink
Blue>Pink
Blue>Pink
Blue>Green>Pink
Blue>Purple
Pink>Green>Purple
Pink>Purple
Pink

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) ---
  The Post-it switch, made real — RCV-IRV: Green eliminated, Blue 10, Purple 9
 Tabulating 20 ballots (ranked ballots).

ROUND 1
Candidate      Votes  Status
-----------  -------  --------
Purple             7  Hopeful
Blue               6  Hopeful
Green              4  Hopeful
Pink               3  Rejected

ROUND 2
Candidate      Votes  Status
-----------  -------  --------
Purple             8  Hopeful
Blue               6  Hopeful
Green              5  Rejected
Pink               0  Rejected
Blank Votes        1  Rejected

FINAL RESULT
Candidate      Votes  Status
-----------  -------  --------
Blue              10  Elected
Purple             9  Rejected
Green              0  Rejected
Pink               0  Rejected
Blank Votes        1  Rejected


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

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): Blue
   Outside (3):        Purple, Green, Pink
   One member ⇒ Blue is the Condorcet winner, beating every rival head-to-head.
   RCV-IRV winner Blue is INSIDE the Smith set. ✓
      Not guaranteed — RCV-IRV is not Smith-efficient — but it holds here.
   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/postit_rcv_example/cases/bv2178_8kg698_irv.yaml

The Post-it switch, made real — RCV-IRV: Green eliminated, Blue 10, Purple 9¶

Scenario¶

Ballots¶

What the engine says¶

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

See also¶