Hear is my Quick synopsis of drillings... I am sure others will add or detract but here goes.

Arc - Drillings are best when one needs to clear the heads because of several reasons.  Drier conditions or little axis rotation.  I use it primarily when trying to get control of the front part of the lane.  Not great for inside deep unless VERY strong ball or monster hand.

Strong- Easier shots, open up the lane shots, etc.  Deeper inside lines.  Can be used up the lane if weaker hand but generally more inside.

Forward Roll- Control over under and over active backends.  Most high rev players can use this and still get strong reaction.   Can tend to leave flat ends if it rolls up to early so you need to get length.  Either by your release or oil.

I actually use in between layouts A LOT.  Half between Strong/Arc and half between Strong/Forward Roll

My thoughts,  Nod