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Hi there!

This week problem features a very surprising voting paradox, which is directly relevant to next week's primaries in the USA. It's a mathematical logic puzzle, designed to stun with the enormous power of strategic voting. It's also a public service announcement which is independently useful for informing the public (just in time for the primaries) that it may not always be ideal to vote for your favorite candidate. We designed it in a bite-sized (mobile) and shareable format so that it could get the point across to as many people as quickly as possible!

Interesting. I believe that with Ranked-Choice Voting Williams would be the winner because only the top 2 with #1 ranking would be considered and then the #2 ranking from the 15% group would be split between them, giving Williams the win with 60% votes. With FPTP, Williams would also be the winner.

With approval voting, assuming they all pick only 2 (as picking 3 would mean everyone gets 100%, and this post already assumes some "perfect voting" anyway), Jones would also be the winner (just like in that post) with points from 100% of the voters. Williams would be voted by 60% of the voters and Smith would be voted by 40% of the voters.

Correct! The fact that this breaks Ranked-Choice Voting is another reason why this is an interesting example. If the each camp in the population were to sit down and think what they'd prefer, the outcome would be in favor of Jones. So, even if they were using Ranked-Choice voting, Camp 2 would strategically vote, putting their favorite at the bottom, so that they end up better off overall.

Actually, Jones is what is known as the Condorcet winner in this election. :)

I'm trying to understand what's the difference between approval voting and this, though. Does this have any advantage over approval voting?

Both systems seem to push the "overall most liked" candidate, but approval voting has no artificial ranking other than "who has the most points", while this one does. Although this one isn't as restrictive as RCV, which says "you have to pick the top 2 before anything gets counted", which only makes it closer to FPTP (even though it should be better than FPTP in some situations).