Generally speaking a ball that is drilled with a pin under does this get the ball into a roll earlier or make in smoother. If not what is the purpose of a pin under drilling, thanks in advance for your help

Generally speaking a ball that is drilled with a pin under does this get the ball into a roll earlier or make in smoother. If not what is the purpose of a pin under drilling, thanks in advance for your help

Pin under does make it little smoother as it also brings the flare rings closer together.  If you take 2 of the same ball and drill one 75 x 5 x 25 and the other one 75 x 5 x 75; the second one is going to transition slower which makes the ball smoother overall.  It wont be a huge difference, but noticeable.  The 75 x 5 x 25 ball will be slightly more angular on the backend.  You will still play pretty much the same area on the lane with both balls (possibly move a board or two with your feet), just the hook shape is going to be different.  It wont be enough of a difference where you would have to make a big 5+ boards move with your feet to adjust for the difference in reaction.  I am including this video of Darren Tang with the Zen Master.  You will notice the difference.  This is a really good demonstration.

https://www.youtube.com/watch?v=TYYdjFuxl-4