The way that duplicates work currently is as follows:
- You can only close as duplicates if the target question has at least one answer that is positively scored or accepted.
- The previous doesn't apply if it's the same user.
This has a slight problem. There are hard questions asked, and those questions can be asked again. So, there may exist duplicate questions that can't be closed merely because those questions haven't been answered.
I propose a slight change:
- Any question can be closed as duplicate of other question
- The previous doesn't apply if the target has no answers and the question being closed as duplicate has any answer.
- The target question shouldn't be closed by any reason.
With this change, the user check and the score/vote check is removed, in favor of simply having answers, and only do so when the one being closed as duplicate has them.
Now why this is better? Well, first of all, it removes the incentive of closing as duplicate of any question just because it has one applicable answer, instead of looking for the actual duplicate. Second, this is how meta works anyways, that way it's not totally surprising.
What problems can the change create? Well, if it's implemented as is, it wouldn't create any problem that I can think off in any scenario, that doesn't happen actually. By my counts, it would potentially solve two problems and create zero, so that's a win.