Every voting criterion STAR fails — with a worked example for each¶
The honest, one-stop index: each formal criterion STAR does not satisfy, what STAR does instead, and a runnable example — the reader page, the tabulatable .yaml, the live BetterVoting election (BV id), and the frozen _bv_export.json where one exists. The prose companion (why each tradeoff is deliberate, and the defenders' replies) is STAR's honest limits; this page is the checklist with receipts.
Read this fairly. No method satisfies every criterion — Arrow and Gibbard–Satterthwaite prove it. STAR passes the ones that bite most in real elections — no center squeeze, monotone (mono-raise), no spoiler/vote-splitting in practice, precinct-summable, no Condorcet loser, favorite-betrayal-resistant — and the failures below are mostly rare, constructed, or deliberate tradeoffs. This is the "safety datasheet" (Voting 401), not a verdict.
The failures, each with a receipt¶
| Criterion | What STAR does instead | Worked example | Run it (.yaml) |
Live BV · export |
|---|---|---|---|---|
| Condorcet — elect the head-to-head winner | scores pick the two finalists, so a Condorcet winner who's only 3rd by score never reaches the runoff | STAR misses the Condorcet winner · three notions of winner | bv2156_…yaml |
BV 3grpbb · json |
| IIA (independence of irrelevant alternatives) | in a Condorcet cycle, a candidate who can't win can flip the result by changing which two reach the runoff | the cycle spoiler | bv2212_…yaml |
BV g3f7r2 · json |
| Later-No-Harm | deliberately given up — scoring a 2nd choice can help it beat your favorite (the price of favorite-betrayal resistance; they're provably incompatible) | Favorite Betrayal 301 (LNH vs FBC, worked) | — | — |
| Favorite-Betrayal Criterion (FBC) | rare lab constructions where ranking your true favorite top can be worse than betraying them | the favorite-betrayal pair (honest vs betrayal-pays) | bv2207_…yaml |
BV b6xrdr (honest: 7mckyg) |
| Majority-favorite | a polarizing majority-favorite can lose to a candidate almost everyone likes (STAR treats that as the right call) | Black Curtain — a polarizing winner / hidden consensus · Majority Criterion hub | (see the set) | (BV-backed set) |
| Mutual majority | a majority-favored set isn't guaranteed one of its own — the residual of vote-splitting | residual vote-splitting | (worked in the page) | — |
| Mono-raise-delete (Woodall) | passes ordinary monotonicity, but raising X and deleting the loser below X can cost X the win | monotonicity worked set § the 301 nuance | page · mono_raise_delete_after.yaml |
LH-only (synthetic) |
| Participation (no-show) | in rare constructions a voter can get a worse result by showing up | participation / no-show set | bv2175_…yaml |
BV 9dhv8y (baseline yyhr66) |
| Consistency (reinforcement) | winning every district separately doesn't guarantee winning the whole — "who advances to the runoff" isn't additive | two districts, one mayor | ex01_district_combined.yaml |
BV 923q3d · json |
Notes¶
- Condorcet, majority-favorite, and mutual-majority are the same mechanism three ways: STAR's finalists come from the score round, so a broadly-preferred-but-low-intensity candidate — or a divisive majority-favorite — can miss the top two. That's the preference-vs-support tradeoff, and it's what separates STAR from Ranked Robin (which elects the Condorcet winner) — see the 30 STAR-vs-RR divergence samples.
- Later-No-Harm and FBC are the deliberate half. STAR chooses to fail LNH to keep favorite-betrayal resistance; RCV-IRV makes the opposite choice. The "failure" is a value pick, and Shentrup argues LNH is a bug, not a feature.
- The mean, one-sided version of this list (curated for sport) is the Mudroom's STAR reel; the fair, cite-in-a-debate version is this page + honest limits.
Sources: each linked case is LH-verified (and BV-verified where a BV id is shown). What STAR passes — and why these tradeoffs are the right ones — is argued in STAR's honest limits and Voting 401.