Scribe lines are used on the pro tour because more than 1 person handles your ball when its getting drilled. Often times the pencil lines would get wiped off by accident when the balls got laid out and then brought to the truck. The people on the truck wouldn't know where to drill the ball, and thus it holds up the process. The scribed lines ensure that the lines will be on the ball when the ball gets passed along on the truck.
The tour truck is not a pro shop per say. The ball are drilled quickly and there are many balls to drill. It's more of an assembly line, than a pro shop. You don't stand there and wait for the ball like at a pro shop. The balls get lined up and they get punched and then you pick up your balls and finish off the holes and install your inserts.
As far as accuracy. It gives the driller a tad bit tighter range to get your span right on every ball. Guys like Mo Pinel make span adjustments in 32nds of a inch, that's a pretty small area to hit with a wax pencil, but it can be done.
Edited by The Dreaded Durbin on 1/15/2011 at 10:21 AM
Edited by The Dreaded Durbin on 1/15/2011 at 10:22 AM