tungwaiyip.info

home

about me

links

Blog

< November 2010 >
SuMoTuWeThFrSa
  1 2 3 4 5 6
7 8 910111213
14151617181920
21222324252627
282930    

past articles »

Click for San Francisco, California Forecast

San Francisco, USA

 

Charting San Francisco Ranked Choice Voting

Last Tuesday, 5 of San Francisco city supervisor's seats are opened for election. San Francisco uses ranked choice voting. Each voter can mark multiple candidate in order of preference. In the initial round, if the top candidate did not get a majority of votes, it goes into instant run-off. The candidates with the fewest number of votes are eliminated. Its votes are transfered to the remaining candidates according to the next preference on each ballot. This process repeats until one candidate obtains a majority of votes among the remaining candidates.

This year 4 out of 5 of the district election has headed for instant run-off. The most crowded field are the 14 candidates competing for district 6 seat and the 21 candidates competing for the district 10 seat. The preliminary election result released (Nov 6) shows the epic battle of over 10 rounds of instant run-off before a candidate wins. To visualize how the process play out, I have charted the election data below.

The colored lines connects the candidates in each round. A circle marks the front-runner and a cross marks the candidates eliminated. Each time a candidate is eliminated, those votes are transfered to the remaining candidates. This "lift" up the line of the next round. In district 6 we can see that the relative position of the top 3 candidate are unchanged through out the process, with Jane Kim leading all the way. District 10 is more dramatic, with the front-runner status pass around the top 4 candidates. We see that Marlene Tran has propelled to the front-runner in round 15 after Teresa Duque was eliminated in round 14 (marked by the red cross). Interestingly no one but Tran has received much of Duque's vote. In a similar fashion, Dewitt Lacy's elimination lift up Maria Cohen. And Steve Moss' votes have passed mainly to Tony Kelly. Finally Lynette Sweet's vote goes mostly to Maria Cohen, making her the winner in under the preliminary result.

The election department is expected to release the final result in a few weeks. It will possibly change the result in a close race such as district 2. I will updated the chart once the data is available.

I have also made a first pass chart that I find not as informative.

To view the election chart it requires a web standard compliant browser with SVG support, e.g. Firefox, Chrome, Safari or Opera. IE 8 or below is not supported. Thank you.

2010.11.08 [] - comments

 

 

blog comments powered by Disqus

past articles »

 

BBC News

 

North Korea ready to talk 'at any time' with Donald Trump (25 May 2018)

 

North Korea's nuclear site destruction: What does it mean? (25 May 2018)

 

GDPR: US news sites blocked to EU users over data protection rules (25 May 2018)

 

MH17: Russia 'liable' for downing airliner over Ukraine (25 May 2018)

 

Mississauga explosion: Suspects 'detonate bomb' in restaurant (25 May 2018)

 

Irish abortion referendum voting opens (25 May 2018)

 

Harvey Weinstein to surrender to police - US media (25 May 2018)

 

Apple awarded in US patent case against Samsung (25 May 2018)

 

Police 'find cash in ex-leader's bags' (25 May 2018)

 

YouTube star John 'TotalBiscuit' Bain dies aged 33 (25 May 2018)

more »

 

SF Gate

 

Bay Area News (7 Jan 2012)

 

City Insider (11 Feb 2012)

 

Crime Scene (13 Feb 2012)

 

C.W Newius Column (10 Jan 2012)

 

C.W. Nevius Blog (11 Feb 2012)

 

Education News (10 Jan 2012)

 

KALW (11 Feb 2012)

 

Matier and Ross Blog (11 Feb 2012)

 

Bay Area home prices hit another record high in April (24 May 2018)

 

Ship traffic, May 25 (24 May 2018)

 

Los Gatos-based Netflix tops Disney to become most valuable media stock (24 May 2018)

 

These companies are hiring a ton of STEM interns — and they'll pay them a lot, too (24 May 2018)

 

Business News Roundup, May 24 (24 May 2018)

 

Uber valued at about billion in new offer to buy company stock (23 May 2018)

more »

 


Site feed Updated: 2018-May-25 03:00