approved by Birkal
CAP's use of ranked voting scripts has been a blessing in many ways, and it is a huge improvement over other voting methods that do not allow for users to vote for multiple candidates. However, Instant Runoff Voting/Preferential Bold Voting are not without their flaws. They do a great a great job at picking a winner where the margin is wide, but there is an uneasy side effect. Essentially, these voting methods work by eliminating the item with the least number of first ranked votes, re-tallying, and repeating until the appropriate number of winners remain. However, when the item with the least number of first ranked votes has barely lower first ranked totals than the item with the most first ranked votes, then there is the potential for "unfair" results.
Take the following scenario:
Option A gets 28 first ranked votes.
Option B gets 30 first ranked votes.
Option C gets 31 first ranked votes.
According to our current voting methods, Option A automatically loses and cannot win. However, it is possible (and has happened once before since I've been a mod) that Option A has much more second place votes than B or C, and thus the majority of people prefer Option A over Option B and Option C when tallied individually with head to head matches.
Take this additional scenario:
Option A gets 30 first ranked votes.
Option B gets 30 first ranked votes.
Option C gets 31 first ranked votes.
IRV/MBV counts both A and B as having the least number of first ranked votes, and eliminates both of them. Option C then automatically wins, and second ranked votes aren't used at all to determine the winner. Though rare, this above scenario shows a complete failure of our voting scripts.
For the purposes of the proposals below, head-to-head vote counting should be a bit more explicitly defined with a more observable. As mentioned above, the implementation of a head-to-head counting method would count every slated item against every other. Option A would be counted against Option B with C removed, then again against C with B removed, and then Option B would be counted against Option C with A removed. Below is what this would look like in small sample size of five votes (and here we're slightly expanding the slate size to four as well).
Person 1 votes for sparktrain, cbrevan, snake_rattler, jas61292
Person 2 votes for jas61292, cbrevan
Person 3 votes for sparktrain, jas61292
Person 4 votes for snake_rattler, sparktrain
Person 5 votes for snake_rattler, cbrevan, jas61292
With the above pool of head to head votes, head-to-head matches would come up with the following:
sparktrain:3 vs cbrevan:2 - more voters prefer sparktrain to cbrevan.
sparktrain:2 vs snake_rattler:2 - the same number of voters prefer sparktrain and snake_rattler.
sparktrain:3 vs jas61292:2 - more voters prefer sparktrain to jas61292.
cbrevan:2 vs snake_rattler:2 - the same number of voters prefer cbrevan and snake_rattler.
cbrevan:2 vs jas61292:2 - the same number of voters prefer cbrevan and jas61292.
snake_rattler:3 vs jas61292:2 - the voters prefer snake_rattler to jas61292.
In the above method, sparktrain is preferred twice and tied with preference once, cbrevan is tied twice and is not preferred once, snake_rattler is preferred once and tied twice, and jas is preferred in no head-to-head match up. The head to head match ups thus display that spark and cbrevan tied, snake_rattler came in third, and jas61292 came in last. To break the tie for first, IRV/PBV would be used.
Proposal A
Initiate a "Close Poll" Clause for final polls in which if the difference between the option with the least first ranked votes and the most first ranked votes is less than X% (I'd propose at minimum 10%, max 20%; a specific number could be up for discussion) then all entries will be compared to each other one on one. As in Option A will be run against Option B with C eliminated and then against Option C with B eliminated, and repeated for all options/combinations. If there's an option that beats the other two one on one, then that option will automatically win the poll, regardless of what IRV says. If there is not an option that beats both others, then the normal IRV/PBV determined winner will be the winner of the poll.
Proposal B
All final polls will tally in a head-to-head match (Option A will be run against Option B with C eliminated and then against Option C with B eliminated, and repeated for all options/combinations. If there's an option that beats the other two one on one, then that option will automatically win the poll, regardless of what IRV says. If there is not an option that beats both others, then the normal IRV/PBV determined winner will be the winner of the poll.) Proposal B aims to bypass trying to make a less-than objective cut off percentage to initiate the head-to-head tallies by requiring them outright in final polls. However, unless voting scripts are changed, this would result in more work for the mods to count the votes and a lot of cases where IRV/PBV obviously got it right will still have to be counted separately.
Proposal C
All CAP competitive polls, not just final polls, will tally head-to-head matches. The three entries that win the most head-to-head matches move onto the final poll. If there is a tie in the number of head-to-head victories that would make more than three entries win, then IRV/PBV would determine which of those tied for third place should move on. If both the number of head-to-head victories and IRV/PBV determine a tie for third place that would result in more than three entries moving onto the next poll, then those tied in third place will all move on. This proposal is perhaps the most extreme of the the three, and would fundamentally change how CAP polls are counted for the benefit of making sure IRV/PBV doesn't mess up in excessively close match ups at any stage. This proposal would undoubtedly require a new programmed voting script that counts head-to-head matches.
It should in general be noted that head-to-head matchups and IRV/PBV will usually, given a decent sample size of votes, both find the same results. However, head-to-head matches and IRV/PBV both have flaws. Head to head matches ignore how much more voters preferred one candidate to another. IRV/PBV ignore the number of raw times that a single candidate to preferred to another single candidate. But, when uses collectively, IRV/PBV and head-to-head matches seem to fix each other's flaws.
In addition to preferences in proposals, this thread will also serve as discussion for proposal amendments and submissions of new proposals that deal with the issue. People who do not like any proposal above and who wish to stick with pure IRV/PBV voting are welcome to reply and explain their reasoning as well.
CAP's use of ranked voting scripts has been a blessing in many ways, and it is a huge improvement over other voting methods that do not allow for users to vote for multiple candidates. However, Instant Runoff Voting/Preferential Bold Voting are not without their flaws. They do a great a great job at picking a winner where the margin is wide, but there is an uneasy side effect. Essentially, these voting methods work by eliminating the item with the least number of first ranked votes, re-tallying, and repeating until the appropriate number of winners remain. However, when the item with the least number of first ranked votes has barely lower first ranked totals than the item with the most first ranked votes, then there is the potential for "unfair" results.
Take the following scenario:
Option A gets 28 first ranked votes.
Option B gets 30 first ranked votes.
Option C gets 31 first ranked votes.
According to our current voting methods, Option A automatically loses and cannot win. However, it is possible (and has happened once before since I've been a mod) that Option A has much more second place votes than B or C, and thus the majority of people prefer Option A over Option B and Option C when tallied individually with head to head matches.
Take this additional scenario:
Option A gets 30 first ranked votes.
Option B gets 30 first ranked votes.
Option C gets 31 first ranked votes.
IRV/MBV counts both A and B as having the least number of first ranked votes, and eliminates both of them. Option C then automatically wins, and second ranked votes aren't used at all to determine the winner. Though rare, this above scenario shows a complete failure of our voting scripts.
For the purposes of the proposals below, head-to-head vote counting should be a bit more explicitly defined with a more observable. As mentioned above, the implementation of a head-to-head counting method would count every slated item against every other. Option A would be counted against Option B with C removed, then again against C with B removed, and then Option B would be counted against Option C with A removed. Below is what this would look like in small sample size of five votes (and here we're slightly expanding the slate size to four as well).
Person 1 votes for sparktrain, cbrevan, snake_rattler, jas61292
Person 2 votes for jas61292, cbrevan
Person 3 votes for sparktrain, jas61292
Person 4 votes for snake_rattler, sparktrain
Person 5 votes for snake_rattler, cbrevan, jas61292
With the above pool of head to head votes, head-to-head matches would come up with the following:
sparktrain:3 vs cbrevan:2 - more voters prefer sparktrain to cbrevan.
sparktrain:2 vs snake_rattler:2 - the same number of voters prefer sparktrain and snake_rattler.
sparktrain:3 vs jas61292:2 - more voters prefer sparktrain to jas61292.
cbrevan:2 vs snake_rattler:2 - the same number of voters prefer cbrevan and snake_rattler.
cbrevan:2 vs jas61292:2 - the same number of voters prefer cbrevan and jas61292.
snake_rattler:3 vs jas61292:2 - the voters prefer snake_rattler to jas61292.
In the above method, sparktrain is preferred twice and tied with preference once, cbrevan is tied twice and is not preferred once, snake_rattler is preferred once and tied twice, and jas is preferred in no head-to-head match up. The head to head match ups thus display that spark and cbrevan tied, snake_rattler came in third, and jas61292 came in last. To break the tie for first, IRV/PBV would be used.
Proposal A
Initiate a "Close Poll" Clause for final polls in which if the difference between the option with the least first ranked votes and the most first ranked votes is less than X% (I'd propose at minimum 10%, max 20%; a specific number could be up for discussion) then all entries will be compared to each other one on one. As in Option A will be run against Option B with C eliminated and then against Option C with B eliminated, and repeated for all options/combinations. If there's an option that beats the other two one on one, then that option will automatically win the poll, regardless of what IRV says. If there is not an option that beats both others, then the normal IRV/PBV determined winner will be the winner of the poll.
Proposal B
All final polls will tally in a head-to-head match (Option A will be run against Option B with C eliminated and then against Option C with B eliminated, and repeated for all options/combinations. If there's an option that beats the other two one on one, then that option will automatically win the poll, regardless of what IRV says. If there is not an option that beats both others, then the normal IRV/PBV determined winner will be the winner of the poll.) Proposal B aims to bypass trying to make a less-than objective cut off percentage to initiate the head-to-head tallies by requiring them outright in final polls. However, unless voting scripts are changed, this would result in more work for the mods to count the votes and a lot of cases where IRV/PBV obviously got it right will still have to be counted separately.
Proposal C
All CAP competitive polls, not just final polls, will tally head-to-head matches. The three entries that win the most head-to-head matches move onto the final poll. If there is a tie in the number of head-to-head victories that would make more than three entries win, then IRV/PBV would determine which of those tied for third place should move on. If both the number of head-to-head victories and IRV/PBV determine a tie for third place that would result in more than three entries moving onto the next poll, then those tied in third place will all move on. This proposal is perhaps the most extreme of the the three, and would fundamentally change how CAP polls are counted for the benefit of making sure IRV/PBV doesn't mess up in excessively close match ups at any stage. This proposal would undoubtedly require a new programmed voting script that counts head-to-head matches.
It should in general be noted that head-to-head matchups and IRV/PBV will usually, given a decent sample size of votes, both find the same results. However, head-to-head matches and IRV/PBV both have flaws. Head to head matches ignore how much more voters preferred one candidate to another. IRV/PBV ignore the number of raw times that a single candidate to preferred to another single candidate. But, when uses collectively, IRV/PBV and head-to-head matches seem to fix each other's flaws.
In addition to preferences in proposals, this thread will also serve as discussion for proposal amendments and submissions of new proposals that deal with the issue. People who do not like any proposal above and who wish to stick with pure IRV/PBV voting are welcome to reply and explain their reasoning as well.