There are 5 different fingerhole pitches that can be drilled in a ball.....

[Hammer]

The five are open, closed, left, right and neutral. In an open pitch the fingers and thumb move away from the palm. An open pitch allows the ball to come off the hand sooner. In a closed pitch, the fingers and thumb move towards the palm. A closed pitch allows the bowler to hold onto the ball longer.
For left and right pitches, the holes are drilled toward the left or right respectively. Left and right pitches also influence the release. For instance in a ball with a right pitch for a right-handed bowler the thumb will angle toward the palm and the fingers will turn out. This style promotes an earlier rotation at the release. The pitch tilts the ball to the inside of the hand earlier in the swing. The opposite is also true. A left pitch allows the ball to sit in the hand so the bowler can stay behind the ball longer through the release point. Finally, there is the neutral pitch, also referred to as a zero pitch. In a zero pitch, the holes are drilled directly toward the geometric center of the ball. So if you decide to get a new ball you might want to ask the pro shop about these different pitches before they do the drilling to see what would be best for you. I didn't even know about this until I read about it in a bowling book. You have to wonder when getting a new ball and the pro shop drills it for you which one of these are you getting as far as pitch. Is one of these a standard for everyone getting a new ball drilled? Evidently you don't drill bowling ball holes just any old way. I thought that I would put this info out there for everyone here in case you would be interested in knowing this info about hole pitch.

[bowl1820]

Which book was this in?

The Pitches are referred to as:

Forward: would be toward the palm.
Reverse: would be away from the palm.
Left Lateral & Right Lateral: Would be right or left from the center of the ball.

Read the pitch section of the:
USBC Bowling Ball Parts & Dynamics Chapter 6
http://www.athletics2000.com/andrew/...20Dynamics.pdf

[Hammer]

This info is in a soft cover book called Bowling-Steps to Success by Doug Wiedman. It goes through every phase of the game as a learning guide for anyone that wants to take up the game.