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It doesn't eliminate the spoiler effect. Here's a simple example of what can happen under RCV: Pretend Bernie Sanders in 2016 ran under the Green Party after d

It doesn't eliminate the spoiler effect. Here's a simple example of what can happen under RCV: Pretend Bernie Sanders in 2016 ran under the Green Party after dropping out of the Democratic Primary. RCV claims to eliminate the spoiler effect, so it is "safe" for all the people who want Bernie as their first choice to actually express that. Assume everyone who likes Bernie the best follows that: they put Bernie as their first choice and either Trump or Clinton as their second choice. Presumably more will have Clinton as their second choice than Trump since Clinton is more centrist than Trump who is on the right. Say the "first choice" votes go as follows: - 45% top choice Trump - 35% top choice Bernie - 20% top choice Hillary Hillary gets eliminated and the people who put Hillary as their first choice now have their second choices distributed among the remaining candidates. Say that split goes (within the 20%): - 6% 2nd choice Trump - 14% 2nd choice Bernie Trump wins, even if all the Bernie voters had Hillary as their 2nd choice, because their second choices didn't count for anything. So the claim that it was "safe" to express their true preferences and put Bernie as their first choice completely backfired. summary: among three choices, under Ranked Choice Voting, you only get your votes moved to your 2nd choice in Ranked Choice if you do not come in 2nd place overall. If your candidate comes in 2nd, your votes are worthless. A system that fixes this and other issues is STAR Voting, and it's what people should be pushing for: https://www.equal.vote/ https://www.equal.vote/ https://www.starvoting.us/ https://www.starvoting.us/

lhopki01 6y ago
Surely in your example STAR Voting would have had the same result? Hilary (and all other lesser candidates of which there are none) get eliminated leaving Bernie and Trump. Then preferences of Hilary voters for those two are calculated (Preference for a runoff between Bernie and Trump are already determined) so you end up with the exact same result.
- heintje_ghulam 6y ago
  You're assuming the scores were chosen from e.g. 1,2,3, and people gave their first preference 1, second preference 2, and third preference 3. So yes, if you force everyone to rank the candidates like in Ranked Choice Voting, in this case you get the same outcome as Ranked Choice Voting. STAR doesn't restrict people to strict ranking though.
  - lhopki01 6y ago
    The only situation where what you say is true is if enough of Hilary's supporters give both Bernie and Trump the same preference number. This is reflected in RCV by not putting a second and third choice. Remember that only the first round takes into account scoring. Runoff only uses relative preference which works out the same as RCV. Also it took me way too long to understand this which makes this seem to me to be a bad system. I've never struggled to understand how a voting system works before and I've used, STV, MMPR, PR, RCV, and FPT. I honestly think proportional representation in a Parliamentary system is way better than any of these complicated system. It's simple to understand, I vote for who I want, and it doesn't end up with the stupid situation of an Executive who can't command support of a Legislative.
alextheparrot 6y ago
The second vote was still counted, though. It just happened that Bernie had 49% (35 + 14) of the vote vs Trump's 51% (45 + 6) in this example? Just because I don't like the hypothetical results of the vote doesn't mean it is wrong.
- heintje_ghulam 6y ago
  The point I was trying to make is that the system doesn't fully reflect peoples' full set of preferences, it chooses some voters' and takes their second choices into account while ignoring others.
  - alextheparrot 6y ago
    Can you help me validate this assumption I've formed based on what you said: The only time this seems to be impactful is when you rank two candidates with the same preference [0]. It seems that otherwise this just creates a roughly equivalent ranking structure. I think that's interesting in a system with many candidates or very similar ideologies, but in this example I would probably expect the same result. Edit: [0] After reading more, I now realize that the initial selection is also the sum of preference votes, so someone could rank Bernie 5, Hillary 4, Trump 0 which could create changes in who the run-off candidates are.
ElijahLynn 6y ago
This post seems logical and takes time to explain the thinking with examples. I don't think it should be down voted (it is grey right now). I have learned about STAR recently here https://www.wired.com/story/dana-debeauvoir-texas-county-clerk-voting-tech-revolution/ https://www.wired.com/story/dana-debeauvoir-texas-county-cle... (A Texas County Clerk’s Bold Crusade to Transform How We Vote) and it is a legit system and has real promise.
grifball 6y ago
I watched the video at your link, but it wasn't very descriptive as to how the votes are actually tallied. This video does a good job of explaining RCV: https://www.youtube.com/watch?v=3Y3jE3B8HsE https://www.youtube.com/watch?v=3Y3jE3B8HsE Is there a similar video for STAR? I can see the problem with RCV now. It doesn't completely eliminate the spoiler effect, just makes it less likely. I understand how votes are cast in each system and they seem similar. STAR seems like RCV, but you can put multiple candidates in the same rank. I'm not sure how STAR votes are tallied, but wouldn't you be able to implement that same system with RCV? The only difference is same-ranking candidates. Is that the key to STAR's improvement? EDIT: Is it just this simple? You sum their score, then instant runoff the top 2?: https://www.youtube.com/watch?v=NuVSn2rAFVU https://www.youtube.com/watch?v=NuVSn2rAFVU I can't tell if it's better or not yet. It still definitely doesn't elect the condorcet winner... which you can see from 3 voters and 12 candidates: Voter 1: 4 for A, 3 for B, 2 for C, 1 for J Voter 2: 4 for D, 3 for E, 2 for F, 1 for J Voter 3: 4 for G, 3 for H, 2 for I, 1 for J It's more contrived than the example for RCV, so I think it's more resistant to spoiler effect, but it clearly happens here. Essentially, every favored candidate higher than 1 is different and they all have the same candidate for their last favorite candidate. As you can see, A,D,G have the most votes, but in 1-on-1 face-offs, J would win most of the elections. Voter 1 likes J more than D,E,F,G,H, and I. Voter 2 like J more than 6 other candidates as well and same with Voter 3. But in STAR, he gets eliminated. I believe you could come up with an example where the top two candidates aren't tied, but it would be more complicated. These voting systems are difficult to measure. I thought RCV was very secure until this HN thread. Hopefully STAR holds up, but I think you'd have to look more into the incentives to fully know if it eliminates the spoiler effect.
- smichel17 6y ago
  > Is it just this simple? You sum their score, then instant runoff the top 2? Yes. First round counts stars, second round just counts preference. If I remember correctly, the main purpose of the second round is to discourage strategic voting -- if you give all other candidates the minimum score, to give your favorite the best chance, then you don't get to express a preference in the runoff, in the event that your favorite is not top 2. So it's only worth doing this if you really like your favorite so much that everyone else is the same to you. > It still definitely doesn't elect the condorcet winner... which you can see from 3 voters and 12 candidates My understanding (from Wikipedia) is that the condorcet winner is "one candidate who beats every other candidate pairwise". Since often no candidate fulfills this criteria, all condorcet systems that expect to survive contact with the real world need to specify a fallback way to choose a winner. I don't know much about the different strategies they use to do this. If my understanding is correct, then it seems like there is no condorcet winner in this scenario (rather, a 3-way tie). So I'm not sure how you expect a condorcet system to handle it.
Buttons840 6y ago
Since you replied to me: I agree, STAR would be better. I also like approval voting for its simplicity. I believe both are better than RCV, but for whatever reason RCV seems to have the hype and I'm not sure whether it's better to try to run with that hype or redirect it towards STAR or approval voting.

lhopki01 6y ago

Surely in your example STAR Voting would have had the same result? Hilary (and all other lesser candidates of which there are none) get eliminated leaving Bernie and Trump. Then preferences of Hilary voters for those two are calculated (Preference for a runoff between Bernie and Trump are already determined) so you end up with the exact same result.

heintje_ghulam 6y ago
You're assuming the scores were chosen from e.g. 1,2,3, and people gave their first preference 1, second preference 2, and third preference 3. So yes, if you force everyone to rank the candidates like in Ranked Choice Voting, in this case you get the same outcome as Ranked Choice Voting. STAR doesn't restrict people to strict ranking though.
- lhopki01 6y ago
  The only situation where what you say is true is if enough of Hilary's supporters give both Bernie and Trump the same preference number. This is reflected in RCV by not putting a second and third choice. Remember that only the first round takes into account scoring. Runoff only uses relative preference which works out the same as RCV. Also it took me way too long to understand this which makes this seem to me to be a bad system. I've never struggled to understand how a voting system works before and I've used, STV, MMPR, PR, RCV, and FPT. I honestly think proportional representation in a Parliamentary system is way better than any of these complicated system. It's simple to understand, I vote for who I want, and it doesn't end up with the stupid situation of an Executive who can't command support of a Legislative.

alextheparrot 6y ago

The second vote was still counted, though. It just happened that Bernie had 49% (35 + 14) of the vote vs Trump's 51% (45 + 6) in this example? Just because I don't like the hypothetical results of the vote doesn't mean it is wrong.

heintje_ghulam 6y ago
The point I was trying to make is that the system doesn't fully reflect peoples' full set of preferences, it chooses some voters' and takes their second choices into account while ignoring others.
- alextheparrot 6y ago
  Can you help me validate this assumption I've formed based on what you said: The only time this seems to be impactful is when you rank two candidates with the same preference [0]. It seems that otherwise this just creates a roughly equivalent ranking structure. I think that's interesting in a system with many candidates or very similar ideologies, but in this example I would probably expect the same result. Edit: [0] After reading more, I now realize that the initial selection is also the sum of preference votes, so someone could rank Bernie 5, Hillary 4, Trump 0 which could create changes in who the run-off candidates are.

ElijahLynn 6y ago

This post seems logical and takes time to explain the thinking with examples. I don't think it should be down voted (it is grey right now). I have learned about STAR recently here https://www.wired.com/story/dana-debeauvoir-texas-county-clerk-voting-tech-revolution/ https://www.wired.com/story/dana-debeauvoir-texas-county-cle... (A Texas County Clerk’s Bold Crusade to Transform How We Vote) and it is a legit system and has real promise.

grifball 6y ago

I watched the video at your link, but it wasn't very descriptive as to how the votes are actually tallied. This video does a good job of explaining RCV: https://www.youtube.com/watch?v=3Y3jE3B8HsE https://www.youtube.com/watch?v=3Y3jE3B8HsE Is there a similar video for STAR? I can see the problem with RCV now. It doesn't completely eliminate the spoiler effect, just makes it less likely. I understand how votes are cast in each system and they seem similar. STAR seems like RCV, but you can put multiple candidates in the same rank. I'm not sure how STAR votes are tallied, but wouldn't you be able to implement that same system with RCV? The only difference is same-ranking candidates. Is that the key to STAR's improvement? EDIT: Is it just this simple? You sum their score, then instant runoff the top 2?: https://www.youtube.com/watch?v=NuVSn2rAFVU https://www.youtube.com/watch?v=NuVSn2rAFVU I can't tell if it's better or not yet. It still definitely doesn't elect the condorcet winner... which you can see from 3 voters and 12 candidates: Voter 1: 4 for A, 3 for B, 2 for C, 1 for J Voter 2: 4 for D, 3 for E, 2 for F, 1 for J Voter 3: 4 for G, 3 for H, 2 for I, 1 for J It's more contrived than the example for RCV, so I think it's more resistant to spoiler effect, but it clearly happens here. Essentially, every favored candidate higher than 1 is different and they all have the same candidate for their last favorite candidate. As you can see, A,D,G have the most votes, but in 1-on-1 face-offs, J would win most of the elections. Voter 1 likes J more than D,E,F,G,H, and I. Voter 2 like J more than 6 other candidates as well and same with Voter 3. But in STAR, he gets eliminated. I believe you could come up with an example where the top two candidates aren't tied, but it would be more complicated. These voting systems are difficult to measure. I thought RCV was very secure until this HN thread. Hopefully STAR holds up, but I think you'd have to look more into the incentives to fully know if it eliminates the spoiler effect.

smichel17 6y ago
> Is it just this simple? You sum their score, then instant runoff the top 2? Yes. First round counts stars, second round just counts preference. If I remember correctly, the main purpose of the second round is to discourage strategic voting -- if you give all other candidates the minimum score, to give your favorite the best chance, then you don't get to express a preference in the runoff, in the event that your favorite is not top 2. So it's only worth doing this if you really like your favorite so much that everyone else is the same to you. > It still definitely doesn't elect the condorcet winner... which you can see from 3 voters and 12 candidates My understanding (from Wikipedia) is that the condorcet winner is "one candidate who beats every other candidate pairwise". Since often no candidate fulfills this criteria, all condorcet systems that expect to survive contact with the real world need to specify a fallback way to choose a winner. I don't know much about the different strategies they use to do this. If my understanding is correct, then it seems like there is no condorcet winner in this scenario (rather, a 3-way tie). So I'm not sure how you expect a condorcet system to handle it.

Buttons840 6y ago

Since you replied to me: I agree, STAR would be better. I also like approval voting for its simplicity. I believe both are better than RCV, but for whatever reason RCV seems to have the hype and I'm not sure whether it's better to try to run with that hype or redirect it towards STAR or approval voting.