What should we do with old [open-ended] puzzles?

Question

Open-ended puzzles are off-topic

The above-linked question ended:

With that being said, I hereby propose that we lock the "good" open-ended puzzles for their historical significance and close the rest.

Perhaps getting rid of the "open-ended" tag would be in order as well?

That didn't happen.

We have a bunch of open-ended puzzles lying around. Occasionally someone adds another answer, further demonstrating why these questions are off-topic. There will never be a provably optimal answer, so more answers will keep coming. And coming. And coming. Along with votes every time the post hits the first page, giving the impression that these are accepted, on-topic questions.

But they're not. We decided that. The tag excerpt says:

OPEN-ENDED PUZZLES ARE NO LONGER IN SCOPE. Used when no answer can be guaranteed to be the last, best one. If a puzzle instead has a provably optimal solution, tag with [optimization].

Is there anything we should do to clean up these old broken windows? I personally started looking through these recently, but I realized that this is a big project and shouldn't be undertaken by a single user without a chance for open input.

So I'm asking for input. What should we do with old open-ended puzzles?

I've posted an answer below. Please vote and add other answers/comments as you wish.

Answer 1

I'm proposing we do a major clean-up of this tag.

This will require a lot of work - there are 147 questions! - and that's probably why it didn't happen before. But these puzzles are causing harm by continually accruing answers, the exact reason they were declared off-topic in the first place. (Also, the fact that no clean-up happened irks my sense of wanting things to be neat and tidy)

We'll need people to look through the questions. Think about each carefully. There are a few things that might be called for:

• This question isn't an open-ended question at all.
  • If it's actually optimization, puzzle-creation, etc. adjust the tags for that.
  • Or maybe the tag doesn't make sense, like this puzzle where I edited out the tag as it was plain wrong.
  • Don't just edit out the tag and leave. Look for more things to improve within the question.
• This question is open-ended
  • It looks like the community didn't care about it (low score/few answers) ⟶ vote/flag to close as "speculative answers"
  • It looks like the community liked it (high score/many answers) ⟶ ping/flag down a mod to see if it warrants a historical lock (not needed since I don't think people are VTD'ing these anyhow)

Above all, coordinate. We probably don't want to flood the front page with all these questions at once, and discussing which category a particular question falls into would be well done in chat.

The tag can be left behind, as a useful way of grouping these old questions, but any new questions with the tag should either be closed or gently directed into fixing themselves to be on-topic.

Answer 2

Leave them be. As you say there are 147 of them, and while it would be optimal for them to be closed, closing them has the unfortunate side-effect of sending an irrelevant and unwelcoming message to someone who asked a perfectly on-topic question years ago.

Edit: the notification was annoying enough, but the stupid system even sent me an email the next day. I know it's not a big deal in the general scheme of things, but really, it's kind of crazy to be sending people stuff like this in 2021 because they posted something for fun in 2016 on a website whose purpose is to post things for fun. I'm not saying the actions of any person are unreasonable, but I do find this email unreasonable in that context.