I've found recently that I have gotten into a bad habit of "grabbing" the ball at the bottom of my swing.  It seems to creep in towards mid to end of the night.  I can feel myself muscling more and my relatively poor carry goes to nearly non-existant. 

What causes this?   

S^2

My thumb generally shrinks during the course of the night. If I do not add tape I find myself gripping the ball tighter. Your thumb can change sizes in just a couple of frames so you have to be conscious of it or you can blow a game away grabbing the ball and not even notice the change is causing you to grab the ball.

I tend to go the other way...  My thumb swells...  I find I need to take 1 piece out about mid 2nd game.....hmm.  coincidence?

good topic, it has a focus goal of mine this year

i have the opportunity to be around some great people who understand the intricacies of today's game.
And they are helpful whenever asked.

for me:
a soft relaxed grip is essential, shortened my grip and re-did my thumb pitch.
be light on your feet, walk softly
loose shoulder at the apex of my back swing
let gravity do the work, just get it off your hand, let the ball do the work

throw your spares at the same pace as your first ball, get your body and muscle memory used to the same pace for all shots.

It takes alot of work to get proper technique and you need someone to watch and tell you when its where it should be so you know what it feels like, then you can work on repeating that same feeling

this will help with accuracy tremendously, especially the sport patterns