Posting in the JY gives an idea of how much people want to talk about your subject before dedicating an entire forum to it. If you're the only person who wants to talk about sports, there is no need for a subforum. If the JY topics pick up Steam, they will be moved to the created Sports forum, which isn't JY-orientation. If they don't pick up Steam, then they will remain JY-oriented, which is where a general topic like that would belong if there isn't enough interest in it to warrant its own forum.