Scenario

Following my discussion on the strategy of voting in recent days, is there any scenario that we really would want to vote for one but not all two candidates?

Yes, there is one.

Consider this: Suppose there is one candidate that you support, another you are neutral to, and the other 8 you are strongly against; one of the 8 is way ahead and would certainly win, the neutral one is in the second place with a marginal lead over your favorite candidate, who is third in the list In that case, voting only for the candidate you support would push him to the second and win.

You may argue: Although this scenario is uncommon, it is the only one that your vote makes a difference. I consider that a subjective judgment: Do we want the one whom we support to win, or those we are against lose?