Usually, when i get a new ball drilled up, i tend to have a good idea of what type of drilling i am going to do on the ball..
And usually it's going to give me a reaction that I can use on a good variety of lane conditions..
here is a example, I have my Track 916AT drilled pin down, under middle finger ( 5.5 from pap ) and the MB is about 1 inch right of the thumb.. I also have this on my 716C.. this is a good layout for me on a wide variety of patterns because the ball reads the midlane very well.. And the backend reaction isnt wild.
I also did this drilling on a 706A and 300A to see what it would do for these balls lol... the 706A works good, and actually seems to be a bit earlier than the 716C.. Now on the 300A, i threw this ball for 1 shot and the ball went very straight lol... So I come next week I will see how this ball works going straighter and bumping it off the dry spot on my league night...
Now on most of my other balls, I usually do a pin up over my fingers or pin right under my fingers.. and the MB anywhere from right next to the thumb hole to over at 45degree's.. And with these layouts I get reactions that can cover a wide variety of lane conditions and makes switching out balls pretty easy.