BowlingTerminology (Part Two): Bowler Specifications

Bowling Terminology (Part Two): Bowler Specifications

by James Goulding III


In this latest blog entry, I am going to define some common terminology to describe terms used when speaking about things related to what and how bowlers impart rotation on the bowling ball.  Things such as rev rate, axis tilt and rotation will be defined, as well as some terms we use when finding points on a bowling ball that aid in drilling them correctly for each bowler.  Again, this is a compilation of terminology pulled from my own experience, as well as outside resources (such as the FAQ section of  Enjoy.





Full Roller: Goes from outside of the ring finger, across the center of the grip, and down across the opposite side of the thumb hole.

High-roller/High-tracker: Within a half inch or sometimes hits the thumb or finger holes, but generally stays just outside of the grip area.

Semi-roller: .5 to 3 inches away from the finger and / or thumb hole.

Low-roller/low-tracker: 3 to 5 inches away from the finger and / or thumb hole.

High-spinner: 5 to 7 inches away from the finger and / or thumb hole.

Low-spinner: more than 7 inches away from the finger and / or thumb hole.


In terms of rev rate (less to higher revolutions):
Stroker – Tweener – Power Player (can be power stroker or cranker)

In terms of wrist and elbow manipulation (less to higher):
Stroker – Tweener – Cranker

(From Brian Pursel: Product Manager, Ebonite)

“RPM’s, or revolutions applied, is the speed of the revolutions.  The faster the revs, the greater the turning force is at the break point. To measure RPM’syou will need a low flare ball (spare ball is good), a piece of tape (4 to 6 inches long), and a video camera.  Place the piece of tape running from the bowler’s PAP to above the fingers.  Film from behind, with a close up of the hand at the release point.  As the ball is being released, stop the tape.  Assign the tape a position on a clock (i.e. the piece of tape points to 10:00).  In slow motion, click off 10 frames and freeze.  Count the amount that the tape rotates as hours, as if it was the hour hand on a clock.  Multiply the amount of hours by 15.  For example, the ball started at 10:00. After 10 slow motion frames the tape ended at 5:00, passing 10:00 once.  One complete rotation around (10:00 to 10:00) counts as 12 hours.  10:00 to 5:00 (the ending position) equals 7 hours.  This is a total of 17 hours of rotation.  Multiply the amount of hours (17) by 15.  This equals 255 RPM’s. 

 The other way to measure revolutions is called hand revs.  You will also need the piece of tape and a video camera for this.  Repeat the steps for measuring RPM’s, however let the ball travel 15 feet down the lane.  This is the distance of the fourth arrow.  Note the starting position of the tape and count the amount of times the ball has rotated using fractions, not hours.  Take the total amount of rotations and multiply by 4.  This equals hand revs.  For example, the ball started at 9:00 and ended at 3:00, passing past 9:00 three times.  This would result in 3 1/2 rotations. 3 1/2 X 4 = 14 hand revs. 

Why do we not count the total amount of revs the ball rotates all the way down the lane until it hits the pins?  Because friction will slow down the ball speed and create additional revolutions.  By using the first 15 feet, we are counting the rotations in the presence of lane oil, a very low friction environment.”


The point that your PAP is facing at release (facing gutter 0°, facing foul line 90°).  Higher degrees of Axis Rotation promote skid and delay ball reaction.


The vertical inclination of you axis at release.  This can be determined by measuring your track diameter (for every 1″ < 13.5″ = 6 2/3° of tilt).  The less axis tilt you have, the sooner the ball will go into a roll.  Higher degrees of axis tilt promotes skid.  Being able to change your axis tilt using your release style is a very important tool in your scoring arsenal and in your ability to be able to play the lane condition properly.


The axis of the ball during the first few revolutions that is created totally by the bowler’s release style. The point on the ball that is equidistant from all points of the release ball track.

Ways to find it (PAP):

Least accurate: Draw a perpendicular (90°) line 6.75″ from your track through grip center.  The end of the line will be close to your actual PAP.

Very accurate: Use an Armadillo Axis point locator tool.  Place the Armadillo on your track using the line that most closely represents your track arc and mark the spot indicated by the Armadillo.  You should seek a qualified pro shop for correct use of such a tool.

Exact: Roll a low flare (spare) ball down the center of the lane where the highest concentration of oil is, then using a grease pencil trace your track.  Place the ball in a spinner with the track down and orient the ball to where while it is spinning, and the trace line doesn’t wobble up and down. Then, take the pencil and place it on the top of the ball and move it around until it goes from making a circle to a defined dot, or use a quarter scale/pro sect tool and draw a line connecting your track at points that are 180° from each other.  Repeat the step at a point near 90° from the first line where the 2 lines intersect, this is your PAP.  If you do not have a low flare ball (plastic ball preferably), you can use any ball as long as you use the track that is closest to your thumb and farthest from your fingers. This is the release track, because as a ball flares the track migrates away from the thumb and towards the fingers.


The number of times the ball rolls over its axis in the first part of the lane before it encounters friction or starts to migrate towards it’s PSA (Positive Spin Axis). This is usually converted into Revolutions per Minute in common bowling terms.


This is the total number of times the ball rolls over it’s axis from the point of release to the pin deck. This is not as accurate a representation of “revs” because it can be influenced by many factors, such as when the ball goes into a roll, and the bowlers ball speed, for example.


With a stop watch, check the time it takes from release to head pin.  I suggest at least five times to get a more accurate average.  Here is the calculation:

(40.91) divided by (ave/time) =  ( ) MPH


Well, those are some of the more common terms used when speaking about bowler specifications.  I hope you found the list informative and eye opening, and have a new found appreciation for the more technical side of the game of bowling.  The next time you hear someone say “I need more axis tilt”, hopefully it will make a whole lot more sense (if you didn’t know beforehand).  Also, a big thanks to and for information, and a valuable resource tool for myself on this page.   The next installment of the Bowling Terminology series will deal with pro shop terms, and how they relate to, and help manipulate, bowling ball reaction.  Thanks again, and I hope to see everyone bowling well out there on the lanes.

James Goulding III

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