International Bowling Pro Shop & Instructors Association​

Glossary of Bowling Terms

Abralon Pad
A foam backed abrasive pad available in several grit ranges allowing “cleaner” sanding, as pores do not clog as quickly as sandpaper. Foam material works like a sponge to help retain water for lubrication during surfacing. Can be used dry as well.

Actual Span
Distance from edge of thumb hole nearest to center, to edge of finger holes nearest to center, including all inserts and/or grips. (See also: True span, full span).

Angle of Entry
Angle, measured parallel to the boards, at which the bowling ball hits the pocket after completing its path
down the lane.

Arc
Ball path from foul line to headpin that does not have a sharp, defined break point.

Arrows
A triangular marking on the lane used by the bowler to target when delivering the bowling ball. These are in the head area of the lane and are usually 5 boards apart and are located approximately 12 to 15 foot down the lane.

Asymmetrical Core
Inner portion of a bowling ball that has a predetermined preferred spin axis designed to help ball motion. This type core will have a different shape when rotated around the top of the core.

Axis Of Rotation
Imaginary line, perpendicular to the track, along which a bowling ball rotates during its path down the lane.

Axis Point
One of two points located on opposite poles marking the endpoints of the axis of rotation.

Axis Tilt
Angle between axis of rotation and the horizontal plane – caused by the bowler at the release, represents an angle of
the axis rotation above a horizontal line through the middle of the ball.

Axis Rotation
The degree that the bowler’s axis is rotated in the horizontal plane towards the bowler at release. Imaginary line, perpendicular to the track, along which a bowling ball rotates during its path down the lane.

Axis Weight
Method of drilling in which the weight block is positioned so that its mass is evenly distributed around the axis of rotation. (Aka: pin on the axis)

Back of Hole
Portion of hole facing away from the center of the grip.

Backend
Fifteen feet of lane directly preceding the headpin.

Backup Ball
Style of bowling in which the movement of the ball is from left to right for right-handers and from right to left for
left-handers. Also known as a “reverse-curve”.

Balance Hole
Extra hole drilled into a ball (usually on the bowler’s vertical axis line) to bring it into USBC specifications for static balance, or to fine tune ball reactions. This hole can increase, decrease, or keep the same ball reaction based on where it is placed. Also called Weight Hole.

Ball Motion
A bowling ball goes through 3 phases once it is thrown. Skid, Hook, and then Roll.

Ball Reaction
Change in direction of the ball’s path.

Ball Track
The portion of the bowling ball that touches the lane. This is determined by the bowlers’ release.

Bevel
The rounding of the top of the holes that are drilled into a bowling ball.

Blister
Raised sac under the skin’s epidermis containing watery fluid, caused by irritation to the area.

Boards
Any one of 39 individual strips of wood pieced together to comprise the surface of the lane (mostly used for targeting). For right handed bowlers board one is next to the right gutter and counted left. For left handed bowlers board one is next to the left gutter and counted right.

Bottom Weight
This is the half of the ball that is opposite the center of the grip. Based on ball weight there are different limitations. This is a measurement required by USBC specifications.

Break Point
Point in the trajectory of a bowling ball at which the ball makes its greatest change in direction.

Bridge
Distance between the finger holes of a drilled bowling ball.

Caliper
A graduated rule with one sliding jaw and one that is stationary.

Callus
Thickened, hardened area of skin caused by build-up due to friction or unusual pressure against the skin.

Carry Down
Oil moved down the lane by the passing of bowling balls.

Center of Gravity
That point in a body or system around which the whole mass is concentrated and may be assumed to act. The point on the surface of the bowling ball where static balance is zero in all directions on a do-do scale – usually marked by a logo.

Center Line
Vertical line that runs from between the fingers to the center of the thumb hole. This is used as a reference when drilling a bowling ball.

Center Line Transposition (CLT)
Lateral shift of the center line, after drilling thumb first.

Conventional Grip
Grip in which the bowler places his/her fingers in the ball to the second joint at a 90º angle, while placing his/her entire thumb in the ball. Normal results from using this type of grip would be fewer revolutions imparted on the ball than using a fingertip grip.

Core
The inner mass of a bowling ball. These are usually different shapes designed to enhance the bowling ball reaction once it is rolled. There are two types of cores used, Symmetrical and Asymmetrical. Also called a weight block.

Cosmetic Bevel
Bevel at the extreme top of the hole which provides a neat appearance to the finished hole.

Coverstock
The outer shell of a bowling ball (composition varies). The type of coverstock on a bowling ball determines how fast the ball loses speed and assists in creating hook.

Cranker
A bowler who generates revolutions by a cupped wrist, bent elbow or muscled arm-swing.

Cut-Span/Cut-To-Cut Span
Distance from edge of thumb hole nearest to center, to edge of finger holes nearest to center, excluding all inserts and/or grips. (See also: Edge span/edge to edge span)

Deflection
Amount of displacement incurred in a bowling ball’s trajectory after making contact with a headpin.

Degree Of Oval
Degree of oval of a hole will be to the center line measured on a horizontal line from the center of the thumb hole.

Differential
Differences in low RG and high RG values of any bowling ball.

Dots
Markings on the approach and lane used for targeting.

Dropped Ring Finger
A fit in which the ring finger span is intentionally shortened to be less than the middle finger span. Some­times referred to as the “Sarge Easter” grip.

Dull Finish (less than 1000 grit)
Surface of a bowling ball appearing without reflection (unpolished). In general, a dull bowling ball is one in which the pours are open and clean.

Durometer
A devise used to measure the hardness of a bowling ball.

Dynamic Imbalance
Measure of weight in an object in motion. Dynamics – Characteristics of the mass inside a bowling ball.

Edge Span/Edge To Edge Span
Distance from edge ot thumb hole nearest to center to edge of finger holes nearest to center, excluding all inserts and/or grips. (See also: Cut Span/Cut To Cut Span)

Equator
Line around the ball, perpendicular to the vertical axis and the midline covering the entire circumference of the ball.

Fingertip
Style of grip in which the bowler inserts fingers to the first joint, with the combined total of angle of the two joints equaling 90°, while placing the entire thumb in the ball.

Finger Weight
Imbalance which effectively makes the side of the ball, divided by the midline, containing the finger holes, heav­ier than the side containing the thumb.

Flare
Refers to the bowling ball changing its axis of rotation while seeking its preferred spin axis during its path down the lane. The result is several distinct oil rings being visible around the ball. (See also: Track flare)

Forward Pitch
The drilled hole, either finger or thumb, is angled toward the mid line (center) of the grip.

Friction
The resistance to motion of two moving objects or surfaces that touch.

Full Roller
A bowler whose track passes between the thumb and fingers and whose track measures the circumference of the ball.

Full Span
Distance from edge of thumb hole nearest to center to edge of finger holes nearest to center, including all inserts and/or grips. (See also: True span, actual span).

Functional Bevel
Any bevel on the ball produced to create a smooth edge or release of pressure on any part, or all, of a hole.

Gravity
Force that tends to draw all bodies in the earth’s sphere toward the center of the earth.

Gripper/Squeezer
Someone who holds on to the ball with excessive force.

Heads
The portion of the bowling lane from the foul line to the range finders which are generally located 15 to 18 feet down the lane.

Helicopter
Type of bowler that has an extremely small ball track usually near the bottom of the bowling ball. The axis of rotation of the bowling ball is vertical to the lane.

High Performance Balls
Balls designed to create specific reactions for different bowlers.

High Track
A track outside of the thumb hole and finger holes that is no more than an inch from either.

Hinge Angle
Angle at which the thumb is connected to the hand.

Hit The Ball
Acceleration of the hand around the ball, from bottom to side, at the release point.

Hook
Amount, measured in boards and angle that a bowling ball deviates from its original trajectory in its path down the lane.

Hook Angle
Angle at which the bowling ball changes direction at its break point.

Hook Potential
Degree to which the properties designed into a bowling ball aid in its potential to traverse boards during its path down the lane.

Horizontal Axis Measurement
Distance, measured perpendicular to the centerline of the grip, along the midline, at which the positive axis point is located.

Imbalance
Displacement of the center of gravity from the geometric center of a bowling ball.

Inside
The portion of the lane bounded by ten boards on each sides.

Label Shift
Displacement of the label from the center of the grip.

Lane Conditioner
Also called lane oil. A substance that is placed on the lane to protect the surface. There are different types made by manufacturers. The type and areas on the lane that it is applied to effects the reaction of the bowling ball.

Lateral Pitches
Right and left components of hole angle In any drilled bowling ball.

Layout
The positioning of the core or weight block in relation to the gripping holes. This is decided before drilling the bowling ball to reach the desired ball reaction.

Leverage Position
In bowling, it is the position at which the bowler is able to use his body to create rotation, speed and mo­mentum on the bowling ball.

Leverage Weight
A drilling in which the center of the weight block is placed at a 45º angle to the axis of rotation.

Line
Intended path of the ball down the lane.

Loft
Distance the ball travels before actually making contact with the lane surface.

Low Track
A track outside the finger holes and thumb hole, but more than two inches from either.

Maple
On a wood lane surface, the type of wood used in the heads and also on the pin deck.

Mark
Point on the lane at which !he bowler is aiming.

Mass Bias
Weight in a particular area of the ball.

Midlane
Line that perpendicularly bisects the center line of the grip. A horizontal line halfway between the fingers and thumb.

Moment Of Inertia
Amount of force required to spin an object.

Negative Axis Point
The point that the ball rotates off of the bowlers hand opposite of the positive axis point (PAP). This is determined by the bowlers’ release.

Negative Side Weight
Imbalance in a ball that effectively makes the left side of the ball heavier for right- handed release play­ers, and the right side of the ball heavier for left-handed release players.

Negative Weight
Imbalance which causes thumb, negative side or bottom weight.

Oil Patterns
The way the oil is distributed on the lanes.

Oval Angle
The degree of oval above the horizontal axis.

Ovaled
The shape of a hole being out of round.

PAP
The point that the ball rotates off of the bowlers hand. (Also known as the positive axis point.) This is determined by the bowlers’ release.

Particle
Small amounts of material added to the shell of a bowling ball during manufacturing.

Pathological Callus
Hard mass of skin surrounded by an inflamed rim.

Pie Chart Formula
Theory that breaks fitting a ball to the bowlers hand in to three parts – span, pitches and hole sizes. The standard starting percentages being 40% span, 40% pitch, and 20% hole sizes.

Pin
A small round discoloration on a bowling ball that marks the top of the core/weight block.

Pin Action
The manner in which the pins react to the impact of the bowling ball.

Pin Deck
The portion of the lane where the pins are placed. Typically they have markings where the pins are to be placed.

Pine
On a wood lane surface, the type of wood used from the end of the heads to the pin deck.

Pin Shift
The process of creating reaction in a bowling ball by displacing the pin from the axis of rotation or the PAP.

Pitch
The angle at which a hole is drilled into a bowling ball in relationship to the center of the ball.

Polyester
Coverstock of a bowling ball comprised of plastic. It is the coverstock with the least amount of hook potential.

Positive Axis Point (PAP)
Point on the surface of the ball that is the end of the bowlers axis of rotation, on the positive side of the ball.

Positive Weight
Imbalance which causes finger, positive side or top weight.

Positive Side Weight
Imbalance that effectively makes the right side of the bowling ball form the center of grip heavier than the left for right handed release player, and left side of the ball heavier than the right for left handed release player.

Preferred Spin Axis
The axis about which the bowling ball wants to rotate. Also known as PSA

Radius of Gyration
An account of the distribution of the mass in an object.

Reactive Resin
Coverstock of a bowling ball. Also known as Reactive Urethane. It has a higher hook potential than polyester or all urethane.

Reactive Urethane
Coverstock of a bowling ball comprised of materials used to make a urethane coverstock with different additives to help the bowling ball adhere to the lane. Also known as Reactive Resin.

Release Point
Point in the delivery at which the ball leaves the hand.

Resurface
A process done to remove an extremely small portion of the coverstock. This is done to get the worn down track out of a bowling ball so that the bowling ball will make better contact with the lane.

Reverse Pitch
The drilled hole, either finger or thumb, is angled away from the midline (center) of the grip.

Reverse Block
A lane condition in which the inside portion of the lane is covered with less conditioner than the outside.

Revolutions
The number of times the bowling ball makes a complete rotation about its axis during its path down the lane.

Roll
The third phase of ball motion. This phase begins when the bowling ball stops hooking and is rolling straight. When the bowling ball reaches this phase pin carry increases.

Rotational Energy
Spin or revolutions of the ball caused by the bowler. (See also: Angular Velocity).

Safe Zone
The area on the ball from one inch inside the vertical axis line to a line from the bowlers PAP to the ring finger and from the PAP to the equator, in which the pin of a ball can be placed safely without the track and holes interfering with one an­other.

Semi Tip
A grip in which the bowler places his/her fingers in the ball between the first and second joint while placing the entire thumb in the ball. (Not a recommended grip pattern).

Shell
The outer portion of a bowling ball surrounding the core.

Shiny
A ball that looks glossy. In general, shiny balls have fewer open/exposed pours.

Siaair
A foam backed abrasive pad available in several grit ranges allowing “cleaner” sanding, as pores do not clog as quickly as sandpaper. Foam material works like a sponge to help retain water for lubrication during surfacing. Can be used dry as well.

Side Weight
The difference in ball weight from the right half to the left half of the center of the grip. This is a measurement required by USBC specifications.

Skid
The portion of the bowling ball’s path in which the velocity of the contact point on the ball is greater than zero and the ball is therefore actually not rolling but is instead sliding down the lane.

Snap
A ball path which has a sharp, defined breakpoint. However, when referring to the actual break point, the term snap is often used as a quantifying term.

Span
Distance from edge of thumb hole nearest to the center, to the edge of finger holes nearest to the center.

Spinner
A bowler who has a type of release that the ball track covers only a small portion of the surface of the bowling ball.

Squirt
The action of a bowling ball as it hydroplanes past its breakpoint.

Stacked Leverage
A layout where the pin and CG are the same distance from the bowler’s positive axis point

Static Weight
The weight difference in the bowling ball. This is measured from the top to the bottom, the left side to the right side, and the finger to the thumb with the center of the grip used to measure from. This is a measurement required by USBC specifications.

Measurements of forces at work in systems that are at rest – side, finger and top.

Stroker
A bowler who has a smooth swing and delivery without sudden acceleration.

Surface
The texture, both finish and hardness, of a bowling ball.

Surface Management
Adjusting the surface of a bowling ball to help with ball reaction. This can be done by using different grits of sanding pads, different types of bowling ball polishes, or a combination of both.

Synthetic Lanes
Type of bowling lane. This surface is harder than wood. There are different types made that are different hardness.

Symmetrical Core
Inner portion of a bowling ball designed to help ball motion. Also called a weight block. This type of core looks the same when rotated around the top of the core.

System of Bowling (SOB)
USBC regulations concerning balls, pins, lanes and dressing distribution.

Tapered
When a drilled hole is worked out at the top more than at the bottom. Usually done to shape the hole to fit the thumb properly.

Target
What a bowler is looking at on the lane to roll the ball over.

Targeting
When a bowler sets their feet in a specific spot on the approach and looks at the lane to determine the path in which they want the bowling ball to roll. Most lanes have dots on the approach to help set your feet in the same place. The bowling lane has dots and arrows, some lanes even have dark ‘marker’ boards down the lane to help find a target.

Three Piece Ball
A bowling ball manufactured with a coverstock, a core, and a filler material between the coverstock and core.

Thumb Weight
A imbalance in a bowling ball which effectively makes the half of the ball containing the thumb heavier than the half containing the fingers, separated by the rnidline.

Top Weight
This is the half of the bowling ball where the grip is drilled. Based on bowling ball weight there are different limitations. This is a measurement required by USBC specifications.

Track
Area of bowling ball that makes contact with the surface during its path down the lane. Because of revolving motion, this area is usually in the form of a ring or rings around the ball.

Track Flare
The result of the migration of a bowling ball from the bowler’s axis of rotation to the ball’s preferred spin axis.

Track Flare Management
The regulation of the position of the flare intersections and thus the amount of flare.

Traction
The power, as of tires on pavement, to grip or hold to a surface while moving, without slipping.

Translational Energy
Created by the ball traveling down the lane towards the pins.

True Positive Axis Point (True PAP)
The axis point for a bowler taken from a ball with minimum track flare potential.

True Span
Distance from edge of thumb hole nearest to center, to edge of finger holes nearest to center, including all inserts and/or grips. (See also: Full span, actual span).

Tweener
A bowler possessing qualities of both a power player and a stroker. Often considered middle of the road in power and finesse.

Two Piece Ball
A bowling ball that is manufactured with a coverstock and a core.

Vertical Axis Line/Mid-Plane
A line perpendicular to the midline that passes through the bowler’s positive axis point and the negative axis point when extended completely around the ball. Separates top of ball from bottom of ball on the bowler’s axis of rotation.

Vertical Axis Measurement
The perpendicular measurement from the midline to the bowlers PAP.

Weight Block
Traditionally, the dense part(s) of material found in the interior of a bowling ball.

Weight Hole
Extra hole drilled into a bowling ball to bring it into USBC specifications for static balance, or to fine tune ball reaction. This hole can increase, decrease, or keep the same ball reaction based on where it is placed. Also called Balance Hole.

Wood Lanes
Type of bowling lane. Wood lanes are made of maple and pine wood. This surface is usually softer than a synthetic lane surface.