Riverbend mayor, one machine's readings altered: evidence account

The contest

Title: Riverbend mayor, one machine's readings altered

Candidates: Ames, Bell, Cruz.

Records in this count: 60.

Ballot file: comparison-altered-machine

Source: Synthetic committed CVRs. No real election was counted.

Sixty ballots, twenty to a precinct, one reading machine to a precinct. The papers hold Ames 22, Bell 28, Cruz 10. reader-3 recorded ten of its Bell papers as Ames, so the machine readings report Ames 32, Bell 18, Cruz 10. Each row is one physical ballot; `paper` is present only where the paper differs from the machine reading. This is a fixture, not a sealed container.

Where the records sat:

One stack of 60 records. There is no ballot manifest of sealed containers.

No container custody was supplied.

What was configured

Configuration version: comparison-altered-machine-plurality-v1-under-bridging.

Configuration fingerprint (SHA-256): d7b1bb6b6d1279278ed31917fa4ef470cdbe502c3a18777c0445899ed3aeb184.

Counting rule: the bridging rule.

Ballot rules used: Two or more marks at one rank end the ballot there; 2 ranks in a row left blank end the ballot; a candidate marked again lower down counts as a rank left blank.

Ballot file: comparison-altered-machine. A third party with this file can rerun the count.

Audit: none. No seed was used.

Configured audit risk limit: 10%.

Plain-language configuration (check against statute intent):

Configuration version: comparison-altered-machine-plurality-v1-under-bridging

Fingerprint (SHA-256): d7b1bb6b6d1279278ed31917fa4ef470cdbe502c3a18777c0445899ed3aeb184

Election: Riverbend mayor, one machine's readings altered, counted under bridging (approved across the room's differences)

A demonstration configuration over committed fixture records, counting the same ballots under another rule. No audit ran under it, and no real election was counted under it.

Contests and candidates:

Riverbend mayor, one machine's readings altered (mayor): Ames; Bell; Cruz.

Counting rule: bridging (approved across the room's differences).

Tiebreak: not used under this counting rule.

Ballot rules (how marks become a ranking):

Two or more marks at one rank: the ballot counts up to that rank and no further.

A candidate marked again lower down: that rank counts as a rank left blank.

2 ranks in a row left blank: the ballot counts up to there and no further.

A mark for anyone not on the ballot: a mark, so the rank is not blank, but never a vote.

Audit risk limit: 10%. A risk-limiting audit that runs under this configuration stops when the sample confirms the outcome at that limit, or sends the contest to a full hand count.

How a ballot is counted and how an audit stops are fixed by this version. Changing any of the lines above requires a new version id.

The count

What follows is the counting account under the bridging rule, including every intermediate step.

The rule

1. Every answer is one ranking of the drafts. A draft a ranking does not name is ranked last on that ranking, level with every other draft it does not name.

2. Each pair of drafts is set against each other: how many rankings put the first above the second, and how many put it the other way. The pair whose smaller side is largest is the question the room divides on.

3. The room is split in two on that question: the rankings that put one of the two above the other, and the rankings that put it the other way round. A ranking with no preference between those two counts on both sides.

4. On each side, a draft's support is the share of that side's comparisons it wins. Each ranking on the side compares the draft with each other draft: above counts one, below counts nothing, no preference counts a half.

5. A draft's standing is its support on the side where it is weakest. The draft with the highest standing stands. If two drafts are level on it, nothing stands.

What was counted

Ballots in this count: 60.

Ballots from: Synthetic committed CVRs. No real election was counted.

Sixty ballots, twenty to a precinct, one reading machine to a precinct. The papers hold Ames 22, Bell 28, Cruz 10. reader-3 recorded ten of its Bell papers as Ames, so the machine readings report Ames 32, Bell 18, Cruz 10. Each row is one physical ballot; `paper` is present only where the paper differs from the machine reading. This is a fixture, not a sealed container.

How the marks on a ballot were read:

Two or more marks at one rank: the ballot counts up to that rank and no further.

A candidate marked again lower down: that rank counts as a rank left blank.

2 ranks in a row left blank: the ballot counts up to there and no further.

A mark for anyone not on the ballot: a mark, so the rank is not blank, but never a vote.

The rankings the ballots form, and how many ballots form each. A candidate a ranking does not name is ranked last on those ballots.

The question the room divides on

Each pair of drafts, both ways round. The smaller side is the count on the side fewer rankings took, and the pair whose smaller side is largest is the question the room divides on.

The room divides on Ames against Bell.

The side that ranked Ames above Bell

32 rankings put Ames above Bell, and 10 took no side on that question and count on both sides: 42 rankings on this side.

Points are the comparisons a draft wins on this side: above counts one, below counts nothing, no preference counts a half.

The side that ranked Bell above Ames

18 rankings put Bell above Ames, and 10 took no side on that question and count on both sides: 28 rankings on this side.

Points are the comparisons a draft wins on this side: above counts one, below counts nothing, no preference counts a half.

Support across the sides

A draft's standing is its support on the side where it is weakest.

What stands

Cruz stands: its support on the side where it is weakest is 42.86%, higher than any other draft's.

Records with no mark, by contest and by machine

At the close of polls, the share of records with no mark in each contest, by contest and by machine. Leaving a contest blank is a voter's right; an outlier below is a question about the ballot or the machine, not a verdict.

The audit

No audit ran.

What was found

No audit ran, so there are no sample findings.

Custody: none supplied. No container custody chain was recorded or verified.

Why it stopped

Decision: no audit.

No audit ran.

Outcome status: preliminary. Software tallies stay preliminary until an audit on the record confirms them or a full hand count of the record replaces them.