I have a pinky hole drilled in all my stuff. A couple of balls also have index finger holes, but you have to watch that as it will make you track higher and you'll probably thump the index finger hole.

 

The more common by far is the pinky hole. Yes, it helps with wrist strain, as you are now supporting the weight of the ball across three fingers rather than two. It's also a bit easier to get tilt on the ball (for me). It's easier to project the ball down the lane (for me). 

 

Drilling the pinky hole doesn't have to be nearly as precise as the other two, but any little bit helps. The way I do mine is to measure 20 degrees southeast of the centerpoint of the bridge, leave 1/2 inch between the cut of the ring finger and the cut of the pinky finger, then drill the pinky hole and pitch it the same as the ring or 1/8 inch further away, depending on how deep I'm going to drill.

 

Once you get used to it, it's hard to go back. 

 

Jess