I dare you all to pour yourself 4 to 6 different examples, 3 of each style, and have a friend help you taste them all blind, and you declare which ones are "alt" and which are "Oktoberfest/maerzen". Or, actually... how many altbiers have you all tasted in your lives?? I have never been to Germany. I would guess that most other style nazis like me have not been there either. So who is to say, really, what the differences are? The BJCP?? I place about as much trust in the BJCP as..... well, maybe it's better than nothing. Sometimes. Maybe.