Coming from the regular Stack Overflow, the high quality of discussion on Math Overflow is very noticeable. Questions are well presented and detailed, answers and comments are thorough and precise.
What specific steps or policy changes have been made that have led to or ensure this? Is this merely a byproduct of the nature of the profession?
What part, if any, does Math StackExchange have in this? Is there an unspoken threshold to meet when asking a question below which the discussion is directed to the aforementioned site instead?