Well the time tested method is where you place the fingers in first and roll the ball back on to your thumb.

Thumb in first and then the fingers has been a long time method to try and take some off the ball. Like for shooting at a ten pin.


here's from Ron Clifton:

" If the lanes are really dry, try placing your thumb into the ball first and then your fingers. Think about throwing the ball more with your thumb, keeping your hand open and relaxed as you go through the release. Try to make your follow-through long and low instead of reaching for the sky. "


Experimental Tip # 1: Thumb in First to Reduce Grip Pressure
Written by Joe Slowinski
Thursday, 01 February 2007
Read about an experiment to help reduce your grip pressure. Can you imagine putting your thumb in the ball first? Well, you might be surprised at the results. This can be very effective in playing the extreme outside on short patterns or when you want to create a more consistent reaction.

http://bowlingknowledge.info/index.php?option=com_content&task=view&id=83&Itemid=62

depending on your release technique, comfort, and your ability to grip the ball consistently, choose your favorite method and do that.

Early in my bowling life I was told to put my thumb in last because it comes out first.  I have done so ever since, and don't even know how it would feel to reverse the order.  --  JohnP

To me I look at it as common sense. Your thumb must exit the ball first, so it is last to go into the ball. 

Placing the thumb in first minimizes the tendency to "grab" at release. When I am bowling on a touchy sport shot where the least bit of grab causes my ball to scoot past the break point, I will often resort to this strategy with pretty good results. This especially works for those "old school" releases, where the hand is more on the side and
in line with, or above the ball's equator.