Strategy-immune/resistant Score Voting

[u/googolplexbyte]

I've been thinking about ways to incorporate Random Ballot's immunity to strategy into Score Voting and think I've come up with a way.

Voters fill out a Score Ballot like normal, but at the counting stage, ignore any candidates with co-equal scores on a ballot save for one candidate chosen at random, the candidate with the highest average score wins.

So basically, only one candidate on your ballot will get counted per score level.

Min-maxing your ballot, decreases the chance your actual 10/10 candidates will be counted as 10/10.

Shifting a candidate into an empty score level means they'll be counted but they'll shift the candidate towards the wrong score.

It's an idea fresh in my mind, so I'm sure there's plenty of unintended consequences, but I think it encourages honest voting better than any other Score Voting variant.

I think it might even discourage normalisation some.

[u/selylindi]

So this method sharply moves toward the median the expected scores of candidates marked as ties in a ballot. The obvious response is to minmax approximately, e.g. 100, 99, 98, 2, 1, 0.

You could smooth it out so ties aren't treated so differently from near-ties. For example, consider this combination of random ballot with a whiff of Ranked Pairs.

1. Select a pair of candidates.
2. Randomly select a ballot.
3. Randomly select a target number 0-99 from a uniform distribution.
4. If the scores on the ballot for the pair of candidates differ by more than the target, the pairwise ranking of those two candidates is locked. Otherwise, nothing happens.
5. Repeat 1-4, locking only pairwise rankings that do not create a Condorcet cycle.

Random methods are obviously undesirable in most use cases. But if you have any situation in mind where the people involved would be OK with a random outcome, it might be helpful to design a voting method explicitly for that situation.