# Questions with an objective win criterion, but no strategy to achieve it

The Answer-Chaining Fibonacci and One OEIS after another challenges have quite a curious win condition. Quoting the former:

## Winning

The winner of the challenge will be the person who posted the second most-recent submission (i.e., not the person who posted last, since they broke the chain).

This condition is objective, but there’s nothing I can do to try to win: I have to make sure not to break the chain, which is within my control; but I also have to make sure the next person writes an answer that breaks it, which is entirely out of my control.

This is silly, and it makes me think that the condition is only in place to awkwardly fit this fun answer-chaining activity into the site rules.

Is this kind of win condition okay? Should we host competitions where you can technically win, but you can’t even try to win?

• As the author of Answer-Chaining Fibonacci, I agree that the winning condition is awkward. But, it would've been shut down immediately without it, so ... Sep 22, 2017 at 12:57
• The first challenge I remember doing this was Add a Language to a Polyglot Sep 22, 2017 at 17:39
• Some answer-chaining challenges have the user who has posted the most answers after the chain is broken wins.
– Okx
Sep 24, 2017 at 13:18
• For what it's worth, the Japanese game of Shiritori uses these rules: the last answer loses (because the game ends). Sep 28, 2017 at 17:32
• That’s not quite the same: in shiritori there is one loser and (n − 1) winners. It’s not a competition, either — more of a pastime for bored kids.
– Lynn
Sep 28, 2017 at 18:38
• For the fibonacci one you can at least remove common characters that are needed by other languages. For the oeis one I definitely agree with what you're saying here. That challenge is going on 11 pages of answers at this point... Might want to just close that one at some point
– Poke
Nov 17, 2017 at 15:34

This was originally a comment, but it became too big. It doesn't provide a single answer per se, but more of a collection of ideas.

First of all, I think I disagree with

there’s nothing I can do to try to win

In the two examples, making more answers increases the chance that you will win, and making more answers is what we should be incentivizing. There is nothing you can do to improve an individual answer's chance of winning, which is I think you take issue with, but overall you can increase your chances of winning by producing more answers.

That being said, I don't think this is the best winning criterion for . While it does incentivize more answers, it only does so probabilistically and, like what I think you are getting at, there is nothing you can do to improve an individual answer. I think this winning criterion works best when each answer is harder than the last, which is not the case for one OEIS after another. Even in cases where it does increase in difficulty, it's not the best, as it doesn't really encourage answers to do anything other than to be valid.

As a challenge writer I would suggest doing something along the lines of "each answer counts as n-points towards its poster with the one that breaks the chain counting negative", but that doesn't really help answer the question.

All in all, I don't know what we can or should do about this. I'll let other people sort that out since I don't have a strong opinion. Until then, I'll just downvote any challenge I don't think incentivizes good answers.

• +1 for the last sentence... Sep 22, 2017 at 19:01

# There is a strategy to win.

Consider a KoTH where you won by making trades with other bots. By itself, the bot can't do anything to win. However, if you make the assumption that other bots will want to trade, then there's an obvious strategy: Trade.

This is true for "second most-recent submisison" posts. By yourself, you are completely unable to win. However, if you make the assumption that other people are going to post, then there's an obvious strategy: Make a post.

Given that this is a programming puzzle site, and that posts are quite popular, I think that the assumption is often (but not always) a safe one.

• There’s no way to post an answer in a way that tries to win, though. I like to think we care about more than sheer quantity on here!
– Lynn
Sep 22, 2017 at 21:26
• I agree, "posting an answer" is the only way to try to win. It's not like you can post a (valid) answer that doesn't try to win. It's a binary state: If you posted an answer, you tried to win, if you didn't you didn't try to win. Sep 22, 2017 at 21:48
• There is a sense in which it's more trying not to lose than trying to win. Sep 23, 2017 at 9:01
• @NathanMerrill Unless you posted a deliberately hard sequence, trying to break the chain. Sep 23, 2017 at 14:30