I'm in the jumpseat out of ORD a couple of days ago. RWYs 32L, 4L, and 9R are in use. The captain briefs two possible routings for each runway!!! I could tell that the FO stopped listening halfway thru the briefing. When they get the taxi clearance, the captain guns the engines, and darts across two taxiways while the FO finishes reading it back. The FO writes down the clearance and then traces it on the 20-9 with his finger. Now, who is the safer pilot?