RCV-IRV (Hare) — the method US "RCV" actually means¶

The single-winner instant-runoff method on the Hare elimination rule: drop the candidate with the fewest first choices, transfer, repeat. When an American ballot or statute says "Ranked Choice Voting," this is almost always it.

→ Family overview: Which RCV-IRV? · why the name confuses: RCV vs. IRV vs. RCV-IRV · where it came from: origins & spread

In one line¶

Count everyone's first choices. If someone has more than half, they win. Otherwise eliminate the candidate with the fewest first choices, hand each of those ballots to its next still-standing choice, and repeat until a candidate holds a majority of the active (non-exhausted) ballots — or only two remain.

The rule is named for Thomas Hare (1857). "Hare" doesn't describe the ballot; it describes which candidate is eliminated each round — the fewest-first-choices one. That single design choice is what separates Hare from every other method on this variants page.

How the count works, step by step¶

Tally each ballot's top choice.
Does any candidate have > 50% of the active ballots? If yes → winner.
If no, eliminate the candidate with the fewest first choices.
Each eliminated ballot moves to its next ranked, still-standing candidate. A ballot whose choices are all eliminated is exhausted and sits out the rest.
Go back to step 2.

Batch elimination is a common shortcut: in one step, drop every candidate who is mathematically out of reach (their total plus all transferable votes below them can't catch the next candidate up). It usually yields the same winner as one-at-a- time Hare and just speeds the count; North Carolina's "instant runoff" statute is written this way.

Worked example — the 27-voter center squeeze¶

The repo's minimal squeeze, all on ranked ballots:

12  Left   > Center > Right
 9  Right  > Center > Left
 6  Center > Left   > Right

First choices: Left 12, Right 9, Center 6 (27 total; majority = 14).

Nobody has 14. The fewest first choices is Center (6) → eliminate Center.
Center's 6 ballots have Left next → Left 12 + 6 = 18, Right 9.
Left has 18 of 27 → Left wins.

But look who got cut: Center is the Condorcet winner — Center beats Left 15–12 and beats Right 18–9 head-to-head. Hare eliminated the one candidate a majority preferred over each rival, because Center was too few voters' first pick. That's center squeeze, and it is specific to this Hare rule — BTR, Coombs, and Baldwin/Nanson all elect Center on these very ballots.

(Verified on the engine: 06_Other/RCV_IRV/RCV_IRV_tabulation_engine elects Left; STAR and Ranked Robin elect Center.)

What your 2nd choice actually does — and when it does nothing¶

This is the part of Hare that most people never get told plainly, so here it is on its own.

Your ballot sits in exactly one candidate's stack at a time — the highest-ranked candidate on it who is still in the race. It is one vote, in one pile. Your 2nd choice is not half a vote for anyone. It is an instruction: "if my 1st choice is knocked out, move me here." An instruction that never fires does nothing at all.

So while your favorite is still standing, the rest of your ballot is not being counted. It is not being counted a little. It is not there. It becomes real only at the moment your favorite is eliminated, and if that never happens, nobody ever reads it.

That has a consequence people find genuinely surprising: a candidate can be ranked 2nd by a huge number of voters and receive nothing from them. There is a worked instance of exactly that in the next section — 20 voters rank Birch second, Birch wins the election, and not one of those 20 rankings contributes a single vote to Birch's total.

The same fact is also Hare's best feature, which is why it is worth understanding rather than just complaining about. Because your lower rankings are never read while your favorite survives, adding them can never hurt your favorite — that is later-no-harm, the property Hare advocates most prize, and STAR does not have it. Invisibility and the guarantee are one mechanism seen from two sides: IRV protects your first choice by ignoring the rest of your ballot, and scored and pairwise methods read all of it and give up that protection. Which trade you prefer is the real argument; pretending either side gets both is not.

Worked example — five rounds, and the bar keeps dropping¶

The 27-voter squeeze above finishes in one elimination, which is the smallest an IRV count can be. Crowded real fields are not like that, and the difference is not cosmetic — it is where "the ballot is simple, the count is not" (is RCV simple?) stops being an assertion.

A town picks one species for its main street. Six on the ballot, 100 voters, and most people rank only the one or two they actually care about — which is what voters do in a crowded field.

20 × Ash>Birch>Cedar        10 × Cedar>Birch      5 × Elm>Birch
10 × Ash                     8 × Cedar            4 × Elm
24 × Birch>Dogwood           8 × Dogwood>Birch    4 × Fir>Elm
                             4 × Dogwood          3 × Fir

--- RCV / Instant-Runoff Voting (single winner) ---
  Street trees — five rounds, and the bar keeps dropping
 Tabulating 100 ballots (ranked ballots).

ROUND 1
Candidate      Votes  Status
-----------  -------  --------
Ash               30  Hopeful
Birch             24  Hopeful
Cedar             18  Hopeful
Dogwood           12  Hopeful
Elm                9  Hopeful
Fir                7  Rejected

ROUND 2
Candidate      Votes  Status
-----------  -------  --------
Ash               30  Hopeful
Birch             24  Hopeful
Cedar             18  Hopeful
Elm               13  Hopeful
Dogwood           12  Rejected
Fir                0  Rejected
Blank Votes        3  Rejected

ROUND 3
Candidate      Votes  Status
-----------  -------  --------
Birch             32  Hopeful
Ash               30  Hopeful
Cedar             18  Hopeful
Elm               13  Rejected
Dogwood            0  Rejected
Fir                0  Rejected
Blank Votes        7  Rejected

ROUND 4
Candidate      Votes  Status
-----------  -------  --------
Birch             37  Hopeful
Ash               30  Hopeful
Cedar             18  Rejected
Elm                0  Rejected
Dogwood            0  Rejected
Fir                0  Rejected
Blank Votes       15  Rejected

FINAL RESULT
Candidate      Votes  Status
-----------  -------  --------
Birch             47  Elected
Ash               30  Rejected
Cedar              0  Rejected
Elm                0  Rejected
Dogwood            0  Rejected
Fir                0  Rejected
Blank Votes       23  Rejected


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

Three things happen here that a three-candidate example structurally cannot show.

1. The lead changes hands. Ash leads rounds 1 and 2 on 30 first choices. Birch passes Ash in round 3 — 32 to 30 — and is never headed again. Reporting this election from its first-choice totals would have named the loser, which is why RCV-IRV results must always be read to the final round.

2. The majority bar moves — down. Every ballot whose ranked species are all eliminated stops counting (the report files these under "Blank Votes"; the precise taxonomy is at exhausted ballots). The active pile shrinks, and the bar shrinks with it:

After round	Active ballots	Majority needed	Leader
1	100	51	Ash 30
2	97	49	Ash 30
3	93	47	Birch 32
4	85	43	Birch 37
final	77	39	Birch 47 — elected

Birch wins on 47 votes. The election opened needing 51. The winner never reached the bar the contest started with; the bar came down to meet him. That is not a trick — it is arithmetically correct and it is how every IRV election works — but it is why "majority winner" needs reading carefully: 47 of the 77 ballots still active is 61%, while 47 of the 100 people who voted is 47%. (What that word is doing: false majorities. Whether voters chose to stop ranking or were capped by the ballot is a separate and important distinction: forced vs voluntary exhaustion.)

3. Twenty second-place rankings that never counted. Look at the 20 × Ash>Birch>Cedar bloc — a fifth of the electorate, ranking the eventual winner second. Ash is never eliminated, so those ballots sit in Ash's pile from the first count to the last and their Birch ranking is never read. Birch's 47 contains none of them. Change all 20 to Ash>Cedar and the count is identical, round for round. That is the previous section made concrete.

Read this fairly — it is not a pathology case. Birch is the Condorcet winner here, beating every rival head-to-head, so Hare landed on the same species STAR or Ranked Robin would. The complaint on this page is about the cost of following the count, not about a wrong winner — which is precisely what makes it worth handing to someone who likes RCV-IRV. For the case where the count also gets the answer wrong, that's the 27-voter squeeze above.

Full report and the pairwise audit: street_trees_five_rounds_c6_b100.md · run it yourself: .yaml · the same count set beside STAR's two steps: How the count works, step by step.

Strengths¶

Familiar and adopted. It's the method actually in use — Maine, Alaska, New York City, San Francisco, and dozens of US cities — so "RCV" reform usually means Hare.
Beats plain plurality at the spoiler problem: a trailing similar candidate is eliminated and transfers, instead of splitting the vote outright.
Later-no-harm: ranking a lower choice can never hurt your top choice (a property Hare advocates prize — though it's the flip side of the squeeze).

Weaknesses¶

Center squeeze — eliminates a broadly-liked moderate who'd win every head-to-head (center squeeze).
Not monotonic — ranking a candidate higher can cause them to lose (non-monotonicity).
Not Condorcet — can fail to elect a candidate who beats all others pairwise.
Not summable — precincts can't just add up totals; ballots must be centralized to run the rounds (summability; what the central count costs in practice — logistics, audits, trust: central tabulation).
Exhausted ballots when rankings are limited (exhausted ballots).

→ The full run-down of IRV's limitations and the claims made for it that don't hold up: RCV-IRV misconceptions & false claims. Head-to-head vs STAR: RCV-IRV vs. STAR.

Where it's used¶

US single-winner "RCV" (Maine statewide, Alaska, NYC primaries, SF, ~50 cities); internationally it's Australia's Alternative Vote for the House of Representatives and was the UK's 2011 AV referendum proposal. The multi-winner relative is STV.

Sources: Instant-runoff voting — Wikipedia, Where RCV is used — FairVote, NYC Board of Elections — RCV