Skip to main content

5.6.1 EDGE method explained — how pitch is placed at edge of oval

EDGE method explained — how pitch is placed at edge of oval

5.6.1   pitch

 

The EDGE method is one of the core calculation approaches available in Spectre Cloud's Oval Calculator. It determines where pitch is applied relative to the oval cut by placing the pitch reference point at the edge of the oval rather than at its centre. Understanding how and why this works helps you make informed decisions about which oval calculation method is right for each bowler.

🎳 What the EDGE Method Does

When drilling a finger hole with an oval cut, the hole is not perfectly round — it is elongated along one axis. This means there are two possible reference points for applying pitch: the centre of the oval, or one of its edges. The EDGE method anchors the pitch measurement to the leading edge of the oval cut — the point on the oval that is closest to the bowler's palm.

In practical terms, this means:

  • ✅ The pitch angle is calculated from the edge of the oval, not its geometric centre.
  • ✅ The resulting hole position is shifted slightly compared to a centre-referenced method — the effective pitch the bowler feels is truer to the intended specification.
  • ✅ For bowlers with forward pitch requirements, the EDGE method tends to produce a snugger, more controlled feel through the release.

📐 The Geometry Behind EDGE

To understand why edge placement matters, consider what happens physically when an oval hole is drilled. The oval adds length to the hole in one direction — typically forward/back or left/right depending on your press setup. If pitch is measured from the centre of that elongated hole, the actual contact point between the bowler's finger and the near wall of the hole is not where the pitch calculation assumed it would be. The finger seats against the edge of the hole, not its centre.

The EDGE method corrects for this by treating the edge as the true reference point from the start:

  1. Spectre Cloud determines the size and orientation of the oval cut based on your settings and the bowler's measurements.
  2. It identifies the leading edge — the point on the oval closest to the palm side of the grip.
  3. All pitch calculations are anchored to that edge point rather than the hole's centre.
  4. The resulting drill coordinates reflect where the hole needs to be placed on the ball surface so that the edge lands at the intended pitch angle.

📌 Note: The difference between EDGE and centre-referenced methods is most pronounced with larger oval cuts (3/8" and above) and higher forward pitch values. For small ovals (1/8") the practical difference is minimal.

⚖️ EDGE Method vs. Centre Method — Key Differences

Factor EDGE method Centre method
Pitch reference point Leading edge of the oval Geometric centre of the oval
Effective pitch felt by bowler Closer to the specified pitch value May feel slightly less than specified
Best suited for Higher forward pitch, larger ovals Smaller ovals, reverse pitch setups
Drill position on ball surface Shifted toward palm to compensate Placed at nominal span location
IBPSIA alignment ✅ Consistent with IBPSIA edge-reference standard Varies by shop tradition

🖥️ How to Select the EDGE Method in Spectre Cloud

  1. Open Settings from your profile menu (top-right corner).
  2. Navigate to the Oval Calculator section.
  3. Locate the Oval Calculation Method preference.
  4. Select EDGE from the available options.
  5. Save your settings. All new spec sheets will use the EDGE method for oval calculations going forward.

🔄 Note: Changing this setting does not recalculate existing spec sheets. Historical records retain whichever method was active when they were created.

✨ When to Use the EDGE Method

  • ✅ When drilling bowlers with moderate to high forward pitch on the fingers — the EDGE method keeps the effective pitch honest.
  • ✅ When using larger oval cuts (1/4" or greater) where centre-referencing would introduce a noticeable discrepancy.
  • ✅ When your shop follows IBPSIA-standard fitting practices and you want Spectre Cloud's calculations to align with that framework.
  • ✅ When bowlers report that their release feels less forward than their pitch spec suggests — switching to EDGE often resolves this without changing the nominal pitch value.
  • ❌ The EDGE method may not be necessary for bowlers with zero or reverse pitch and small ovals, where centre and edge references converge.

🎳 A Practical Example

Consider a bowler with 3/8" forward pitch on the ring finger and a 1/4" oval cut. Using a centre-referenced method, Spectre Cloud would place the hole so that the centre of the finished oval sits at the 3/8" forward pitch position. But the bowler's finger actually contacts the hole at its near edge — which, on a 1/4" oval, is 1/8" closer to the palm than the centre. The effective pitch the bowler feels is therefore closer to 1/4" forward, not 3/8".

With the EDGE method active, Spectre Cloud compensates by positioning the hole so that the edge — not the centre — lands at 3/8" forward. The bowler experiences the pitch they were actually fitted for.

  • 5.6.2 — CENTRE method explained — how pitch is placed at centre of oval
  • 5.6.3 — Choosing between EDGE and CENTRE for your shop
  • 5.5.1 — Setting up: Oval Cut Direction = NONE in Settings
  • 5.5.2 — Using the oval cut chart to determine cuts manually
  • 4.x — Creating and editing spec sheets

✨ Tip: When in doubt, EDGE is the safer default — it keeps the delivered pitch closer to the specified pitch across the widest range of oval sizes and forward pitch values. Most IBPSIA-trained fitters will find it matches their intuitions about where pitch should land.

Back to top