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Board of Supervisors District 5 (SanFrancisco; 2016-11-06)

🔗 2016-11-06_SanFrancisco-Board_of_Supervisors_District_5     (tags: { from-bolson , actual , SF , SanFrancisco_CA , 2016 , 2016-11 , CA , SanFrancisco-2016 })

Below is the ABIF from the "2016-11-06_SanFrancisco-Board_of_Supervisors_District_5" election (Board of Supervisors District 5 (SanFrancisco; 2016-11-06))

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Voting methods: IRV • FPTP • approval • STAR • Pairwise • All methods

Results

🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5

Below are the results of the election represented above using various election methods with abiftool/abiflib. The detected ballot type from the ABIF above is "ranked". Some methods may transform these ballots for analysis; see method notices for details. Resubmit the ABIF with "Transform ballots" turned off to minimize the transformations.

Method Winner
IRV/RCV LONDON BREED
FPTP LONDON BREED
Approval LONDON BREED
STAR LONDON BREED
Condorcet/Copeland LONDON BREED
Election results summary showing voting method winners
click/tap to expand
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IRV/RCV results

2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 IRV/RCV result permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/IRV#IRV

  • IRV/RCV Winner: LONDON BREED with 21,324 votes (46.8%) in final round
  • Runner-up: DEAN PRESTON with 19,697 votes (43.3%) in final round
  • Exhausted ballots in final round: 4,510 (9.9%)
  • Number of rounds: 1
  • Ballots counted in final round: 41,021 (90.1%)
  • Majority of ballots: 22,766 (50.0%)
  • Total ballots: 45,531
Round 1
Overview:
Active ballots: 45,531 (100.0%)

Exhausted ballots: 4,510 (9.9%)
Counted ballots: 41,021 (90.1%)
Winning threshold: 20,511 (45.05%)
IRV/RCV winner:
LONDON BREED: 21,324 (46.8%)✅
→
DEAN PRESTON: 19,697 (43.3%) (🛑eliminated)
→

FPTP result

"FPTP" is "First-past-the-post", also known as "plurality" or "choose-one"
2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 FPTP results permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/FPTP#FPTP
📝
Note — Only using first-choices on ranked ballots

  • FPTP Winner: LONDON BREED with 21,324 first-place votes (46.8%)
  • Runner-up: DEAN PRESTON with 19,697 first-place votes (43.3%)
  • Margin of victory: 1,627 votes (3.6 percentage points)
  • First-place votes
    • LONDON BREED: 21,324 votes (46.8 %)
    • DEAN PRESTON: 19,697 votes (43.3 %)
  • Blanks: 4,510 (9.9 %)
  • Total ballots: 45,531

Approval voting results

2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 approval voting results permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/approval#approval
📝
Note — Approval counts estimated from 45,531 ranked ballots using favorite_viable_half method
Details

The 'favorite_viable_half' conversion algorithm: find the candidate with the most first preferences, and then determine the minimum number of figurative seats that would need to be open in order for the candidate to exceed the Hare quota with the given first-prefs. We use this to estimate how many candidates are likely to be viable candidates.

Using first-choice vote totals as a rough guide, approximately 2 candidates appear viable: LONDON BREED and DEAN PRESTON. The approximation then assumes each voter approves up to 1 of their top-ranked viable candidates (half of 2). All candidates ranked at or above the lowest-ranked of each ballot's top viable candidates receive approval (considering up to 1 viable candidates per ballot).

See transformed ballots

Note: For Approval, these choose_many ballots are inferred from ranked ballots.

Conversion method: favorite_viable_half

#------- metadata -------
{ballotcount: 45531}
{version: "0.1"}
{ballotcount_abif_metadata: "45531"}
{is_ranking_to_rating: true}
#------ candlines ------
=[LONDON BREED]:[LONDON BREED]
=[DEAN PRESTON]:[DEAN PRESTON]
#------- votelines ------
8529:[LONDON BREED]/1
8079:[DEAN PRESTON]/1
8009:[LONDON BREED]/1
7454:[DEAN PRESTON]/1
3438:[LONDON BREED]/1
2722:[DEAN PRESTON]/1
835:[DEAN PRESTON]/1
762:[LONDON BREED]/1
395:[DEAN PRESTON]/1
332:[LONDON BREED]/1
254:[LONDON BREED]/1
212:[DEAN PRESTON]/1
  • Approval Winner: LONDON BREED
  • Approval Results:
    • LONDON BREED — 21,324 approvals (46.83% of ballots) (✅ winner)
    • DEAN PRESTON — 19,697 approvals (43.26% of ballots)
  • Total: 45,531 ballots (41,021 total approvals)

STAR results

2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 STAR results permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/STAR#STAR
📝
Note — STAR ratings estimated from ranked ballots using Borda scoring method
Details

The ranked ballots have been converted to STAR ratings using Borda scoring: each candidate receives points equal to (number_of_candidates - their_rank). In this election, we have 2 candidates, so the 1st choice gets 1 points, the 2nd choice gets 0 points, etc. These Borda scores are then used as STAR ratings for tabulation by STAR.

  • STAR winner: LONDON BREED
  • Finalists: LONDON BREED vs DEAN PRESTON
  • Runoff result:
    • LONDON BREED: 21,324 votes (46.8%)
    • DEAN PRESTON: 19,697 votes (43.3%)
    • No preference: 4510 voters (9.9%)
  • Total stars allocated: 41,021
  • Total ballots: 45,531
★★★★★★

★★★★★

★★★★★★
★★★★★
★★★★★★
★★★★★
★★★★★★
★★★★★
★★★★★★
(one star above is approximately 820 stars allocated by voters)
  • First round:
    • ★#0: LONDON BREED received 21,324 stars (52.0%) from 21,324 voters (46.8%)
    • ★#1: DEAN PRESTON received 19,697 stars (48.0%) from 19,697 voters (43.3%)
  • Finalists:
    • ★LONDON BREED (✅ winner) preferred by 21,324 of 45,531 voters
    • ★DEAN PRESTON preferred by 19,697 of 45,531 voters
    • ★No preference between the finalists: 4510

NOTE: Since ratings or stars are not present in the provided ballots, allocated stars are estimated using a Borda-like formula.

Condorcet/Copeland results

2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 Condorcet/Copeland results permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/pairwise#pairwise
  • Winner: LONDON BREED
  • Runner-up: DEAN PRESTON (beats all other candidates except LONDON BREED)
  • Smallest margin: LONDON BREED over DEAN PRESTON (21,324-19,697; margin: 1,627)
  • Largest margin: LONDON BREED over DEAN PRESTON (21,324-19,697; margin: 1,627)
  • Pairwise ties: none
  • Total ballots: 45,531

Win-loss-tie (Condorcet/Copeland) table

2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 w-l-t table permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/pairwise#wlt
Board of Supervisors District 5 (SanFrancisco; 2016-11-06) pairwise matchups
LONDON BREED
(1-0-0)
LONDON BREED
1 victory ⇣
DEAN PRESTON
(0-1-0)
LONDON BREED: 21,324(46.8%)
DEAN PRESTON: 19,697(43.3%)
(No preference: 4,510; 9.9%)

Pairwise tournament (Copeland ordered)

2016-11-06_SanFrancisco-Board_of_Supervisors_District_5 pairwise diagram permalink:
🔗https://abif.electorama.com/id/2016-11-06_SanFrancisco-Board_of_Supervisors_District_5/pairwise#dot

%3 LONDON BREED LONDON BREED 1-0-0 (1 wins, 0 losses, 0 ties) DEAN PRESTON DEAN PRESTON 0-1-0 LONDON BREED->DEAN PRESTON ← LONDON BREED: 21324 DEAN PRESTON: 19697

Voting methods: IRV • FPTP • approval • STAR • Pairwise • All methods

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