4.1.2 Span types explained: F, C, O, H

How Full Span Is Measured

1. Have the bowler insert their middle and ring fingers into the finger holes to the correct depth for their grip style.
2. With the fingers seated, measure from the tip of the middle finger to the nearest edge of the thumb hole.
3. RecordIt is also referred to as the measurementcomplete in inches, to the nearest 1/16" or in decimal as appropriate for your display setting.

When to Use Full Span

• ✅ The most widely used span convention inand thea industry — thesensible default for most pro shops and— IBPSIA-publishedit fittingdescribes charts.the bowler's actual reach with their grips installed.
• ✅ Intuitive for bowlers to understandexplain, —this describesis basically the actualsize reach from finger to thumb.
• ✅ Best choice when using IBPSIA standard charts as a starting point, since most published values assume Full Span.
• ✅ Suitable for all grip styles — fingertip, conventional, and semi-fingertip.
• ❌ Requiresof the fingersbowler's to be physically inserted to the correct depth during measurement — measurement accuracy depends on consistent finger insertion.hand.
  

📐 Cut to Cut (C)

A Cut to Cut measurement is taken from the nearFull edgeSpan minus the thickness of the insert — the span measured to the actual drilled cut of the finger holeshole, before the inserts are accounted for. It is most useful when you drill the ball thumb-first: rather than mentally subtracting the grip thickness to thefind near edge ofwhere the thumbfinger holeholes —go, edgeyou towork edge,directly entirely onfrom the ball's surface. It does not involve the bowler's hand in the measurement itself; instead it measures the distance between the physical openings of the drilled holes.

How Cut to Cut Is Measured

1. With the ball on the fitting jig or bench, identify the near edge of the finger holes (the edge closest to the thumb hole).
2. Measure from that edge to the near edge of the thumb hole.
3. Record the measurement in inches, to the nearest 1/16" or in decimal.

When to Use Cut to Cut

• ✅ PreferredIdeal byfor fittersa whothumb-first workdrilling primarilyworkflow from— physicalthe ballnumber measurementsalready ratheraccounts thanfor hand-basedthe fitting.insert thickness, so there's no mental math at the press.
• ✅ MoreReferences the physical cut on the ball, making it reproducible across different fitters — the measurement point is fixed on the ball rather than dependent on finger insertion depth.fitters.
• ✅ ParticularlySupported usefulby whena insertsbuilt-in areauto-suggestion in useSpectre —Cloud the(see hole edge position is directly relevant to how inserts seat and the effective grip geometry.
• ✅ Useful for verifying a drilled ball against spec — theAutofill Cut to Cut, can be measured post-drilling to confirm accuracy.2.6.9).
• ❌ Less intuitive for the bowler, since it describes the drilled hole rather than the felt grip.

Watch the terminology: Spectre's Cut to Cut (C) is not the same thing the PBA services truck calls "Cut-to-Cut." The PBA truck's "Cut-to-Cut" (biggest hole to biggest hole) is Spectre's Hole to Hole (H) — see below.

📐 Outer to Cut (O)

Outer to Cut is used when an interchangeable thumb is present. It is measured from the inside of the female portion of the interchangeable to the cut of the finger's outer-diameter hole.

Its purpose is repeat-drilling convenience. When a bowler with an interchangeable thumb comes in for a new ball, you don't need to drill a fresh thumb hole for them. Using the Outer to Cut measurement, the holes land in exactly the right spot, and the bowler simply locks in their own male inner sleeve.

When to Use Outer to Cut

• ✅ Any bowler who uses an interchangeable thumb system.
• ✅ Repeat customers — they can show up, and the ball is ready for their existing sleeve without re-fitting the thumb.
• ✅ Keeps a consistent reference across every ball in that bowler's arsenal.
• ❌ Only relevant to interchangeable setups — not applicable to bowlers drilling a fixed thumb hole.

📐 Hole to Hole (H)

Hole to Hole is measured biggest hole to biggest hole — for example, from a 1 1/2" thumb hole to a 31/32" finger hole. It is a purely physical, edge-to-edge measurement of the largest openings on the ball.

This is the measurement isthe takenPBA fromservices truck refers to as "Cut-to-Cut." Because Spectre already uses "Cut to Cut" for a different measurement (C, above), that PBA convention lives under the name Hole to Hole in Spectre to avoid confusion.

When to Use Hole to Hole

• ✅ Quick physical reference straight off the ball, notindependent theof hand,inserts andor doesgrips.
• ✅ Familiar to anyone coming from a PBA-truck background, where this is called "Cut-to-Cut."
  
• ❌ Does not directly describe the bowler's reach.
felt
• ❌reach Values— areit's a hole-geometry measurement, not directly comparable to Full Span values — converting between the two requires knowing the hole diameter and insertion depth.

📐 Outer-to-Cut Span (O)

An Oval Span spec sheet is one where at least one hole — most commonly the thumb — has been drilled as an oval shape rather than a roundgrip hole. The oval designation does not replace the span measurement; rather it indicates that the hole dimensions include an oval cut, and that the oval calculator values (starting bit, oval width, V/H movement) are part of the spec.

What Makes a Span "Oval"

A standard round hole has a single diameter. An oval hole has been extended beyond the round cut in the vertical direction, the horizontal direction, or both — creating an elongated opening that accommodates the bowler's natural thumb movement through the release.

• ✅ The oval's dimensions are defined by the starting bit size (the round hole) and the additional cut in V and/or H directions.
• ✅ Oval spans are most common for the thumb — the thumb's rotation during release often benefits from an oval that follows the thumb's natural path.
• ✅ The span measurement itself (Full Span or Cut to Cut) is still recorded on an oval spec sheet — the oval designation adds the oval dimensions on top of the standard span record.
• ✅ In Spectre Cloud, the oval calculator (Book 05) generates the V/H movement values and oval width from the bowler's span and thumb measurements.
• ❌ Oval holes require additional care at the drill press — the movement direction, flip settings, and diff values must all be correctly configured before drilling.

When to Use Oval Span

• ✅ When a bowler's thumb does not clear a round hole cleanly through the release.
• ✅ When a bowler reports thumb discomfort, hanging, or inconsistent exit on a correctly sized round hole.
• ✅ When thumb swelling is a recurring issue — an oval provides more clearance without requiring a larger round hole that would be too loose when swelling subsides.
• ✅ For bowlers with a pronounced thumb rotation or side-roll through the release.

📐 Hole-to-Hole Span (H)

An Oval Span spec sheet is one where at least one hole — most commonly the thumb — has been drilled as an oval shape rather than a round hole. The oval designation does not replace the span measurement; rather it indicates that the hole dimensions include an oval cut, and that the oval calculator values (starting bit, oval width, V/H movement) are part of the spec.

What Makes a Span "Oval"

A standard round hole has a single diameter. An oval hole has been extended beyond the round cut in the vertical direction, the horizontal direction, or both — creating an elongated opening that accommodates the bowler's natural thumb movement through the release.

• ✅ The oval's dimensions are defined by the starting bit size (the round hole) and the additional cut in V and/or H directions.
• ✅ Oval spans are most common for the thumb — the thumb's rotation during release often benefits from an oval that follows the thumb's natural path.
• ✅ The span measurement itself (Full Span or Cut to Cut) is still recorded on an oval spec sheet — the oval designation adds the oval dimensions on top of the standard span record.
• ✅ In Spectre Cloud, the oval calculator (Book 05) generates the V/H movement values and oval width from the bowler's span and thumb measurements.
• ❌ Oval holes require additional care at the drill press — the movement direction, flip settings, and diff values must all be correctly configured before drilling.

When to Use Oval Span

• ✅ When a bowler's thumb does not clear a round hole cleanly through the release.
• ✅ When a bowler reports thumb discomfort, hanging, or inconsistent exit on a correctly sized round hole.
• ✅ When thumb swelling is a recurring issue — an oval provides more clearance without requiring a larger round hole that would be too loose when swelling subsides.
• ✅ For bowlers with a pronounced thumb rotation or side-roll through the release.measurement.

📊 Span Types Compared

🔄 Span Type and Spectre Cloud's Auto-Suggestions

Spectre Cloud's auto-suggestion features — including Auto-Calculate Ring Span (2.6.8) and Autofill Cut to Cut (2.6.9) — are aware of the span type selected on the current spec sheet and apply their calculations accordingly.within Thethat 5/16"convention. ringMost spannotably, offsetselecting andCut to Cut enables the Autofill Cut to Cut derivationcalculation bothchain, operatewhich derives the value from Full Span and the insert thickness so you don't have to subtract it by hand.

• ✅ Selecting Cut to Cut triggers the Autofill Cut to Cut behaviour (see 2.6.9).
• ✅ Auto-Calculate Ring Span (2.6.8) operates within the selected span type's convention.
  • ✅ Selecting Full Span on a spec sheet triggers Full Span-appropriate autofill behaviour.
  • ✅ Selecting Cut to Cut triggers the Autofill Cut to Cut calculation chain (see 2.6.9).
  • ✅ Oval span sheets additionally trigger oval calculator fields — the V/H movement values, diff, and oval width appear as part of the spec. ⚠️ Verify with your Spectre team: confirm exactly howwhich theauto-suggestions ovalare spanactive typefor selectionOuter interactsto withCut the(O) ovaland calculatorHole fieldsto inHole the(H), specas sheetthese UI.behaviours may differ from Full Span and Cut to Cut.

  Related Sections

  • 4.1.1 — Understanding acronyms: F, C, OO, H and other Spectre Cloud shorthand
  • 4.1.3 — Creating a new spec sheet (if applicable)
  • 2.3.2 — Span type configuration: Full Span, Edge, Center
  • 2.6.8 — Auto-Calculate Ring Span: based on 5/16" ruleSpan
  • 2.6.9 — Autofill Cut to Cut: based on insert type/size
  • 5.x05 — Oval Calculator: overviewoval andhole gettingshape started(a separate concept from span type O)
  • 9.x — Tips and& Troubleshooting: converting between span types

  Tip: If your shop is establishingsetting itsa default span typetype, convention for the first time, Full Span is the lowest-friction choice — it's the complete measurement most fitters already work in, and it aligns with IBPSIApublished charts,fitting ischarts. familiarReach tofor most experienced fitters, and is intuitive to explain to bowlers. Cut to Cut becomeswhen you drill thumb-first, Outer to Cut for bowlers on interchangeable thumbs, and Hole to Hole when you want the betterbiggest-hole-to-biggest-hole choicereference whenthe yourPBA workflowtruck calls "Cut-to-Cut." Remember: none of these is heavily"Oval" insert-based— orthat's whena post-drillhole verification against the ball is part of your standard process. Oval isshape, not an alternative to the other two — it is an addition to whichever basea span type you use.type.

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