What's the protocol for answering questions which are neither clearly on-topic nor clearly off topic?
Looking around, I find two posts along these lines:
1) "Don't answer - just vtc"
2) "Is it bad etiquette to answer a question you've voted to close?"
Both these topics suppose that you know clearly that the question is off-topic, and although the accepted answers aren't totally cut and dry, it looks like in that circumstance you should probably avoid answering.
But what if it's a grey area? Suppose you see a question and think, "someone might decide to close this as off topic, but maybe not". Or perhaps there is a vote to close, but you don't necessarily agree with it. Should you wait for the vote to run its course and the community to decide whether the question is on topic? Or should you just go ahead and answer?
Example: A question asked "is x a good strategy"? I was aware that "opinion-based" questions were off topic, and that the question would never have a cut and dry answer because x may work better for some people or in some situations. On the flip side, I had personally had very good luck with strategy x, so I answered, stating my experience that it seemed to work. I thought this information, while not a definitive answer, would be helpful to the asker.
The question was later put on hold as "likely to produce only opinion-based answers". Should I have waited to answer, given that I knew the question was... umm... questionable?