Bowling Terminology (Part Three): Ball Drilling

Bowling Terminology (Part Three): Ball Drilling

by James Goulding III


In this last section in the terminology trilogy, I am going to be defining common terms used in the pro shop by ball drillers.  Many people have been told something like “your thumb looks sore, maybe you have too much forward pitch”.  There are plenty of people who may nod their head at that statement, and have no idea what the difference between forward pitch and reverse pitch really is.  Hopefully after reading this, you can gain a more complete understanding of the terminology used in the game of bowling.  ONce again, this is a compilation of terminology pulled from my own experience, as well as outside resources (such as the FAQ section of  I hope you like it.




All L/R pitches are from a right handed point of view when refering to soreness, please reverse for left handed bowlers.

When refering to L/R for fingers and thumb, it is taken as if you’re looking at the back of the hand.

Thumb Pitches:

(+)  Reverse = Earlier thumb exit, increased grip pressure may be required, possible soreness to the front or back of the thumb.

(+)  Forward = Later thumb exit, reduced grip pressure may be required, possible soreness to front or back of the thumb.

(+)  Left = Reduced axis rotation, possible soreness to right side of the thumb at the base and left side at the tip.

(+)  Right = More axis rotation, possible soreness to the left side of the thumb at the base and right side at the tip.

Finger Pitches:

(+)  Reverse = Less lift, earlier finger exit, reduces rotation, possible soreness to the pad side.

(+)  Forward = More lift, later finger exit, increased rotation, possible soreness to nail side, or broken blood vessels under the nail.

(+)  Left = Axis tilt enhancer if all pitches are biased left from your normal pitches, possible soreness to right side of finger tip.

(+)  Right = Possible soreness to left side of finger tip.


(+) Increased  Span = More loft, more axis rotation.  More reverse required, possible soreness thumb tip nail side, thumb base away from nail, blood under thumb or finger nails, finger pads.

(-) Decreased  Span = Less loft, less axis rotation, more forward may be used.  Possible soreness at the crease of first knuckle on fingers away from nail, thumb knuckle nail side, blood under thumb nail (clipping), thumb side away from palm.


With your thumb fully inserted into the ball, lay your fingers across the finger holes.  The midway point between the first and second knuckles should be even with the edge of the hole closest to your thumb.


Drilling the middle finger fingertip while drilling ring finger conventional.
Mostly used by power players to get more consistent release, or to cut down some revolutions and side roll.


This test is used as a starting point for finding your ideal lateral thumb pitch.  You grab the bottle the way you would normally grab any object.  Flip your hand over so that you can see where your thumb is in relation to the rest of your fingers.   If you do not have a Coke bottle, you can also use your non bowling forearm/wrist by placing your hand around the point on your arm to where your thumb almost touches your fingers.

Table (Where the thumb points to):

Index finger = 1/8 lateral away from palm
Between Index and middle = 0
Middle = 1/8 lateral under palm
Between middle and ring = 1/4 lateral under palm
Ring = 3/8 lateral under palm


Pin to PAP distance:

 0″ – minimum flare potential, core is in it’s most stable position, earliest roll with smoothest arc.

1 1/8″ – 1/3 of flare potential, stable core position, earlier roll with smooth arc.

2 1/4″ – 2/3 of flare potential, semi stable core position, early roll with strong arc.

3 3/8″ – max flare potential, most unstable core position, medium length with the most hook potential.

4 1/2″ – 2/3 of flare potential, semi stable core position, late roll with flip/arc reaction.

5 5/8″ – 1/3 of flare potential, stable core position, later roll with a flip reaction.

6 3/4″ – minimum flare potential, stable core position, latest roll with strongest flip.

Remember : These reaction characteristics are all relative to the conditions they are being used on, and may not perform as expected due to burning up too early or not setting up early enough.

Pin to grip center (CG) distance: The higher the pin above grip center, the more length you will get,  depending of course upon the pin to PAP distance.  The pin placement in relation to CG also affects where the tracks of the track flare intersect (bow tie).  Higher pin = Higher intersection.  For this reason, they suggest high trackers place the pin higher above CG reduce the risk of flaring over the finger holes.


As the angle goes from 75° (strong/flip) to 0°, length will be reduced and have more of an arcing type of reaction.  From 75° to 105°, length will increase and the ball will have more of  a flip type of reaction.  Beyond 105°, the reaction will keep a very similar shape, but with added length.

Remember : These only enhance the characteristics of the given ball.  Pin placement in the flip (strong) position may not necessarily have the biggest back end reaction on a given condition, due to many other variables that affect ball reaction (bowlers specs, lane condition, etc.)


The degree system of drilling a ball is when a drill pattern is described or laid out by using the relationship between the angles of the lines from PAP to Pin and Pin to MB.
Examples: (A=PAP, P=Pin, X=MB)

P-A-X is 0°      P-A is 45°    P-A  is 90°   P-A is 135°   X-P-A is 180°
                  \            |            /
                   X           X           X

These are obviously not exact, but they are good enough to get the meaning across.


This system does not use the PAP for reference when describing the layout other than in pin to PAP distance.  It uses the relation between Pin and CG or Pin and MB.  The pin is the hour hand and CG/MB is the clock center.

Example: Pin on bridge line and CG/MB swung at out 45° to the right would be a 10:30 drilling, Stacked=12:00, 45° Left Swing = 1:30, etc.
This system does not give as accurate a description as the Degree System IMHO.


Angling of the thumb hole or finger holes so that the bottom of the hole is pointed toward the center of the grip.


Angling of the thumb hole or finger holes so that the bottom of the hole is pointed away from the center of the grip.  It is used to help the thumb exit sooner.  Although very common, too much reverse pitch can cause the ball to fall off the hand early and may require increased grip pressure, causing you to “grab” the ball at the bottom of the swing.


Left is when the bottom of the hole is biased toward the left side of the ball.
Right is when the bottom of the hole is biased toward the right side of the ball.
Used to assist in the exit timing of the ball (i.e. how fast or easily it comes off your hand).   Improper lateral pitch can cause blisters or sore spots on your thumb or fingers.


 A drilling pattern with the center of gravity located on the bowler’s PAP and the pin in the leverage position.


It is a drilling pattern with both the pin and the cg located 3-3/8″ from the bowler’s PAP, usually requires an extra balance hole to make the ball static legal according to USBC guidelines.

Well, that’s the list of terms that is used by pro shop operators, and advanced bowlers alike.  I hope you found this very informative and can start incorporating these terms into your bowling dictionary.  Once again, a big thanks goes to everyone who contributed to this list, and helping to make it as complete as possible.  You can find most of these terms under the FAQ section of also.  Thank you for reading, and any comments or feedback would be greatly appreciated.

by James Goulding III

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