4.1.5 Bridge: standard bridge sizes and their purpose

4.1.5   concept 

 The bridge is the distance between the near edges of the middle and ring finger holes on a drilled ball — the strip of material, or land area, that holds the two finger holes apart. It's one of the smallest measurements on a spec sheet, but it's an industry-standard value that depends on grip type, and Spectre Cloud defaults it for you. 
 📏 Standard Bridge by Grip Type 
 The bridge default is set by the bowler's grip type: 
 
 ✅ Fingertip — 1/4" — the standard default for fingertip fits. 
 ✅ Conventional — 3/8" — the standard default for conventional fits. 
 
 Spectre Cloud applies the correct default automatically based on the grip type recorded for the bowler (see Autofill Bridge, below). 
 ⚠️ The 1/4" Warranty Minimum 
 Whatever the grip type, 1/4" is the hard floor . Ball manufacturers will not warrant a ball that cracks if the bridge was drilled narrower than 1/4" — below that width, the land area between the finger holes is too thin to reliably survive repeated impact. 
 
 ✅ 1/4" is the fingertip default and the universal warranty minimum. 
 ✅ Conventional defaults wider, at 3/8" . 
 ❌ A bridge narrower than 1/4" risks cracking the land area — and voids the manufacturer's crack warranty if it does. 
 
 🛠️ Autofill Bridge in Spectre Cloud 
 When Autofill Bridge (2.6.5) is enabled, Spectre Cloud pre-populates the bridge field with the standard value for the bowler's grip type — 1/4" for fingertip, 3/8" for conventional — so you don't need to enter it on a routine drill. The fitter only intervenes when a specific, deliberate reason calls for a different value. 
 🖥️ Bridge on the Spec Sheet 
 The bridge field sits in the insert and finger hole section of the spec sheet. 
 
 ✅ It's shown in whatever unit and format your account uses — fractional or decimal, per your display settings. 
 ✅ The autofilled value can be overridden by typing a different measurement directly. 
 ✅ A manually entered bridge is saved to the sheet's history and is visible when the sheet is reviewed or cloned. 
 ✅ When cloning a spec sheet, the bridge carries forward — confirm it's still appropriate for the new ball before saving. 
 
 Related Sections 
 
 4.1.4 — Pitch terminology: Forward, Reverse, Lateral, Zero 
 4.1.3 — Grip type definitions: Fingertip vs. Conventional 
 4.1.2 — Span types: Full Span, Cut to Cut, Outer to Cut, Hole to Hole 
 2.6.5 — Autofill Bridge: 1/4" fingertip, 3/8" conventional 
 9.x — Tips & Troubleshooting: narrow bridge and land area considerations 
 
 Tip: Let Autofill Bridge set the grip-appropriate default — 1/4" fingertip, 3/8" conventional — and treat 1/4" as the floor you never drill below. Going narrower than 1/4" for any grip gives up the manufacturer's crack warranty, so only do it for a specific, documented fitting reason.