Just a coupla point for ya.
What kickass said. Predicting time requires a PhD in chaos theory. There are many variables. Weather, total mass of brisket, fuel characteristics, quantity of brewski's consumed, etc. So plan ahead and give yourself plenty of time. Like say 16 hours of relatively sober attention.
After yur done, and its coolered and the fire is secure, then you'll know what to expect. Then you hand the coolered meat to some one else to serve. You've done your share.
Dr. Mark (STL)
Ph.D. (honorary) Bovine $hitology
A thin line separates paranoia from an acute understanding of reality.