Span is the distance between the edges of the thumb and finger holes; pitch is the angle each hole is drilled in relation to the ball's center. The pro shop also fits hole size to your hand and delivery. USBC recommends an IBPSIA-certified technician to help dial in span, pitch and hole size.
Span, pitch and hole size describe the fit between your hand and a drilled ball. They answer a different question from core-layout measurements such as pin-to-PAP, so ask the pro shop which measurement it is discussing before comparing two balls.
The three fit measurements
| Measurement | What it means and what to ask |
|---|---|
| Span | Distance between the edges of the thumb and finger holes. Ask whether the recorded value includes the inserts or grips. |
| Pitch | Angle at which a gripping hole is drilled in relation to the ball’s center. Ask which forward, reverse or lateral angles are part of this fit. |
| Hole size | Opening for the thumb or fingers. Ask whether it matches the bowler’s hand and release. |
The International Bowling Pro Shop and Instructors Association (IBPSIA) glossary defines span by the edges of the thumb and finger holes and pitch as the angle of a drilled hole relative to the ball’s center. It also distinguishes cut-to-cut span, which excludes inserts or grips, from actual span, which includes them. Use the same measurement convention when comparing notes from different balls.
What to bring to a pro shop
Bring a ball whose fit you like, if you have one, and describe how you hold and release it. Tell the technician whether you use a thumb hole and whether you bowl one-handed or with a two-handed approach. USBC says correct span, pitch and hole size matter and recommends an IBPSIA-certified technician to help fit them.
Ask the pro shop to explain which span convention it uses and whether inserts or a thumb slug affect the fit record. If the holes pinch, slip or require a squeeze, describe that feel before the shop adjusts the ball. The guides to finger inserts and thumb slugs and two-handed bowling equipment fit and rules cover those related choices.
Fit measurements and layout measurements are different
Span, pitch and hole size describe how the hand fits the ball. A layout describes how core markers relate to a bowler’s release; see pin-to-PAP layouts for those measurements. Browse drilling and pro shop guides when preparing to discuss a new ball or a change to an existing fit.
Sources
Common questions
What does span mean on a bowling ball?
Span is the distance between the nearest edges of the thumb and finger holes. Ask whether a shop's record includes the inserts when comparing measurements.
What is pitch in bowling?
Pitch is the angle at which a hole is drilled relative to the ball's center. A pro shop can explain the forward, reverse or lateral pitch used for your fit.
What is the difference between cut-to-cut and actual span?
IBPSIA distinguishes cut-to-cut span, which excludes inserts or grips, from actual span, which includes them. Ask which measurement a shop records.
Who should measure bowling ball span and pitch?
USBC recommends working with an IBPSIA-certified technician to get the span, pitch and hole size fitted to your hand.