why are some answers suddenly "hidden"?

Some answers are suddenly hidden because Yahoo have introduced a new feature (ie only some people are seeing it and not others because it is based on browser cookie). We've seen this in the past with the new layout, rating schemes etc.

Basically from what can be seen (and this is because Yahoo have not announced anything formally) then if you see a new sort option for answers on a question called "Relevance" If you see that then you may see "hidden" answers.

From looking at answers which are being hidden then it seems to be basing them on the content itself and evaluating how relevant they are to the question. e.g. short answers seem to be the ones hidden a lot, as are answers which are questions rather than answers. Also answers which don't seem to contain relevant keywords to the questions.

Today I noticed that one of my answers was also hidden and I was able to "unhide" it again

/question/index?qid=20140... I had posted the same text without the first two sentences. In theory I answered the question as it was asking for example of questions but it determined that my answer had little relevance to the question (and I can imagine that answering a question with a question is one of those factors).

By adding "There are a number of questions you can ask in order to get a hit from a spammer. Here are a couple of examples: " then it un-hid again (nice test though as it showed that you can unhide your answers by editing them).

It should be noted that Yahoo have not even informed us of this feature as yet. Even when they do, it's unlikely that they will give us a breakdown of how it is determined as that would be counter-productive and just lead to people doing enough to meet requirements only and that we will be left to work it out roughly e.g. same for calculation of how a TC badge is awarded, e.g. same for working out how the reporting mechanism works on Y!A

wtf this isnt an answer site no answer

They hide the answers from posters who have a low percentage of helpfulness. You are both hilarious and unhelpful in most of your answers.

New feature, sort by relevance. Just change your sort preference.