<p>It seems to me there is no hard rule about when you should move something to chat (e.g. after the 11 comment mark) but I can tell you my perspective as someone who enters a question to see a long thread of comments-- </p>

<p>The common sense approach would tell me that you should move it to chat if you don't see the back-and-forth ending in the very near future, since this would end up leading to potentially dozens of comments. In that situation a new person entering the question would need to read through a long list of comments before they can figure out what is going on. To me personally, that is off-putting and will make me less likely to participate in the question at all. </p>

<p>Another thing to note: if the thread of comments/chat ends up leading to a useful conclusion and/or a significant change to the question at hand, you should consider making corresponding edits to the question, so new people entering don't have to read through the entire discussion. </p>
