It may also be that he just paces better and has a higher tolerance than most. There can also be other "side effects" of downing 1 serving of yeast + yogurt per beer you plan to have so perhaps that helps limit his intake as well (if he sticks to the pre-plan), heck pre-planning probably helps more than anything.
http://www.reddit.com/r/Homebrewing/comments/23wbeo/jim_koch...
It may also be that he just paces better and has a higher tolerance than most. There can also be other "side effects" of downing 1 serving of yeast + yogurt per beer you plan to have so perhaps that helps limit his intake as well (if he sticks to the pre-plan), heck pre-planning probably helps more than anything.