Voting Systems

Strategically changing electorial boundaries to get advantage
e.g.
Candidate 1 wins Candidate 2 in District A
Candidate 3 wins Candidate 2 in District B
But Candidate 2 has the most voters national-wide

Gerrymandering Explained — CGP Grey
Gerrymandering Explained - YouTube
{% youtube Mky11UJb9AY %}

Multiple Party Gerrymandering [Bonus Video] - YouTube
{% youtube uR2DfpjIuXo %}

How Gerrymandering Works | HowStuffWorks
Gerrymandering: How to Stifle Democracy | Stuff You Should Know

Solution:

independent commission
shortest split-line (it's math)
proportional gerrymandering (to reflect voter's intention)

Gerrymandering from DataGenetics

RangeVoting.org - Splitline districtings of all 50 states + DC + PR
RangeVoting.org - Gerrymandering and a cure - shortest splitline algorithm

Spoiler Effect

When an 3rd candidate joins the election and steals votes from the original candidate of similar political view, it can make the other candidate win by a larger portion

Alternate Voting

The Alternative Vote Explained - YouTube
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The Alternative Vote Explained — CGP Grey

Politics in the Animal Kingdom: Single Transferable Vote - YouTube

Voters put the candidates on a preference list
The voting loops until one candidate get the majority votes
Each round the candidate with the least votes get eliminated, with his vote passed to the next on the voter's List

Single Transferable Vote/Ranked Choice Voting

Instant‐runoff voting - Wikiwand
Single transferable vote - Wikiwand

Politics in the Animal Kingdom: Single Transferable Vote - YouTube
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Extra: STV Election Walkthrough - YouTube
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Politics in the Animal Kingdom: Single Transferable Vote — CGP Grey

Like Alternative Voting, but extra votes are given to next alternative.

Citizens rank their favorite candidates.
Any candidate above the threshold wins immediately,
'Extra' votes go to their next choice.
If no winner, last place is eliminated, and the votes to go their next choice.
Repeat until all the winners are found.

How Ranked-choice Voting Works | HowStuffWorks
How Ranked Choice Voting Works | Stuff You Should Know

Approval Voting

Voters can vote for any number of candidates

Mixed-Member Proportional Representation

Mixed-Member Proportional Representation Explained - YouTube
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Mixed-Member Proportional Representation Explained — CGP Grey

Council seat is doubled
First round is traditional FPTP choosing half of the council seats
Party prepare list to be added to the council after the 1st round

PLTP

Method for direct election for Hong Kong's Legco member.

Party-list proportional representation - Wikiwand

Arrow's Impossibility Theorem

Arrow's impossibility theorem - Wikiwand

When there are three or more candidates, there's no "nice" way to vote for a winner. Collective choice is always manipulative, either cycling or dependency of irrelevant alternative is inevitable.

UK's failure

Why the UK Election Results are the Worst in History. - YouTube

measure misrepresentation error, the difference of percentage points between what a party gets in the election and what their representation in the parliament

H.I. #37: Penguins and Politics — Hello Internet
HI 37 — CGP Grey (1:16:03)

United Kingdom Alternative Vote referendum, 2011 - Wikiwand

Butterfly Effects | 99% Invisible US 2000 presidential election, election history and UX