Quote Originally Posted by d0zer
Once you grind enough, you should be reasonably aware what standard levels of variance and their deviance are to the point where you can intelligently set your BRM to where you feel comfortable.

Some of us are more conservative than others but beginners should always err on the side of conservative...
... but in fact due to their noob-ness tend (until they get advice) to err on the other side, unfortunately.