Layout Calculator
The Layout Calculator helps you compute ball drilling layouts using four industry-standard methods. Choose your layout method, set your bowler profile, and get calculated pin placement, angles, and distances — complete with step-by-step marking guides you can hand directly to your pro shop.
Getting Started
You can open the Layout Calculator from the My Layouts screen by tapping the + button and selecting Layout Calculator. You can also choose Recommend My Layout for a guided wizard that picks the best method for you automatically.
Bowler Profile
At the top of the calculator, you set your bowler profile. This information shapes the calculation for every method:
- Style — Stroker, Tweener, or Cranker. Selecting a style auto-fills recommended starting values for the active calculator.
- Grip — Thumb or Two-Hand/No-Thumb. The calculator adjusts recommendations based on your grip type.
- PAP (Positive Axis Point) — If you have saved a Bowler Spec Sheet, your PAP coordinates are loaded automatically. Tap Edit to update them.
Tip
Fill out your Bowler Spec Sheet first. It stores your PAP, grip measurements, rev rate, and ball speed so every calculator starts with accurate data instead of defaults.
Layout Methods
The calculator supports four methods. Switch between them using the segmented control at the top of the screen.
Dual Angle
The most widely used modern layout method. It uses three values to define pin placement and mass bias position relative to your PAP:
- A (Drilling Angle) — The angle from the VAL (Vertical Axis Line) to the pin, measured in degrees (0-90). Controls how early or late the ball reads the lane.
- B (Pin-to-PAP Distance) — The distance in inches from the pin to your PAP (1-6.5"). Controls the amount of flare.
- C (VAL Angle) — The angle from the VAL to the mass bias position, measured in degrees (0-90). Controls the shape of the backend reaction.
The calculator also displays derived values: Sum (A + C, which indicates total hook distance) and AI (Asymmetry Index = A / C, which indicates hook shape).
Two input modes:
- Recommended — Answer five questions about your game (axis tilt, speed vs. rev rate, hook distance, hook shape, flare level) and the calculator produces the A, B, and C values for you.
- Exact — Enter the A, B, and C values directly using stepper controls. The calculator validates your inputs and flags any values that fall outside normal ranges.
PAL (Pin Above Line)
A guided method that works from your PAP coordinates and three distance measurements:
- Pin-to-PAP — Distance from the pin to your PAP (controls flare).
- PSA-to-PAP — Distance from the Preferred Spin Axis to your PAP.
- PAL (Pin Above Line) — How far above the midline the pin sits (controls track flare and ball motion).
Strength presets let you quickly load values for common reaction strengths. The result shows a layout notation like 4" x 5" x 2" along with the calculated midline distance.
2LS (Two Locating Surface)
A two-measurement method popular for asymmetric balls. It uses:
- Pin-to-PAP — Distance from the pin to your PAP. Controls flare potential and how early the ball reads the lane.
- MB-to-PAP (Mass Bias to PAP) — Distance from the mass bias marker to your PAP. Controls backend shape and continuation.
Like Dual Angle, 2LS has both Recommended and Exact modes. In Exact mode you can also specify whether the ball core is asymmetric or symmetric. The result includes a color-coded reaction label (e.g., "Strong Angular" or "Length with Backend") so you can quickly see the expected ball motion.
Symmetrical
A guided method designed for symmetric-core balls. Instead of entering exact measurements, you choose two placement zones:
- Pin Position — Above Fingers (length and smooth arc), Below Fingers (earlier read, more hook), or In the Palm (max flare, strong backend).
- CG Placement — In the Track (balanced), Kick Left/RH (smoother, more length), or Kick Right/RH (more hook, earlier read).
The calculator uses your PAP coordinates to produce a reaction prediction and step-by-step drilling instructions including pin-to-PAP distance ranges and static weight checks.
Tip
Not sure which method to use? Dual Angle is the industry standard for asymmetric balls. Symmetrical is designed for symmetric-core balls. If your pro shop asks for PAL distances, use the PAL method. The 2LS method is a quick alternative when you only need pin and mass bias placement.
Marking Guides
Every calculator includes an expandable Marking Guide below the result. This is a numbered, color-coded walkthrough that tells you (or your pro shop operator) exactly how to mark the ball before drilling:
Locate and mark the PAP
Roll several shots and identify the spot on the ball that rotates the least. Mark it with a sharpie dot.
Draw reference lines
Draw the axis line through the PAP and the perpendicular VAL. These are your zero-degree references for angle measurements.
Measure and mark angles/distances
Follow the method-specific steps to position the pin and mass bias (or CG) at the calculated angles and distances from your PAP.
Verify before drilling
Confirm all measurements, check USBC pin buffer regulations, and take a photo of the marked ball for your records.
Bowler Spec Sheet
The Bowler Spec Sheet is a dedicated screen that stores all your drilling measurements in one place, modeled after an industry-standard drill card. It includes:
- PAP Measurement — Over distance (2-8"), vertical distance (0-3"), direction (up/down), and measurement method (rolled on ball, measured with tape, or pro shop verified).
- Ball Delivery — Rev rate (RPM) and ball speed (mph). These are optional but improve layout recommendations.
- Handedness — Right or left-handed.
- Grip Measurements — Grip type (conventional, fingertip, semi-fingertip), span for middle and ring fingers, and pitch values for middle, ring, and thumb.
- Inserts and Thumb — Finger insert brands/sizes, thumb size, thumb slug, and interchangeable thumb details (brand, size/model).
- Notes — Free-text field for any additional drilling preferences.
PAP values use 1/16" increment steppers for precise entry. Once saved, your spec sheet data is automatically loaded into every calculator session.
Tip
Ask your pro shop to verify your PAP measurement. Select Pro Shop Verified as the method once they confirm it. An accurate PAP is the single most important input for every layout calculation.
Saving Layouts
After computing a layout, tap the Save button in the top-right corner. The save dialog lets you:
Name the layout
The calculated notation (e.g., "60 x 4 1/2" x 35") is pre-filled as the name. You can change it to something more descriptive.
Link to a ball (optional)
Select a ball from your arsenal to link this layout to. Linked layouts are grouped under their ball on the My Layouts screen.
Add notes (optional)
Record why you chose this layout, what condition it is for, or any other details you want to remember.
The save also records your PAP, handedness, the calculation method, all input values, the computed result, and any validation warnings for future reference.
Tip
Link layouts to their ball so you can compare different layouts for the same ball side by side on the My Layouts screen.
My Layouts
The My Layouts screen is your library of all saved layouts. Layouts are grouped by linked ball, with unlinked layouts in a separate section at the bottom.
- Search — Filter layouts by name, notes, or ball name using the search bar.
- Filter — Filter by method (Dual Angle, PAL, 2LS, Symmetrical), linked/unlinked status, or layouts received from a coach.
- Sort — Sort by newest, oldest, name, or ball name.
- Detail View — Tap any layout to view the full detail screen with all inputs, computed results, validation warnings, and the option to edit notes, link/unlink a ball, favorite, or delete.
Each layout card shows a color-coded method badge (DA, PAL, 2LS, SYM, or MAN for manual entries), the layout notation, date, and any notes.
Layouts from Your Coach
If you are connected to a coach through the Tournament Sense Coach app, your coach can send you recommended layouts. These appear at the top of your My Layouts screen with a coach badge showing the coach's name. Tap Save to Mine to add a coach layout to your personal library. If the coach specified a ball name that matches one in your arsenal, it is automatically linked.
Manual Entry
If you already know your layout notation, you can skip the calculator entirely. From the Add Layout sheet, select Enter Manually to type in a notation directly (e.g., "60 x 4 1/2" x 35"), optionally link it to a ball, and add notes.
Recommend My Layout
The Recommend My Layout wizard is the easiest way to get a layout. It loads your spec sheet data, lets you select a ball from your arsenal, choose your desired ball motion and lane condition, and then generates a recommended layout using the calculation engine. This is ideal for bowlers who want a data-driven recommendation without needing to understand the math behind each layout method.
Validation and Warnings
The calculator validates your inputs in real time. You may see three types of alerts:
- Errors — Values that are outside allowable ranges. You cannot save a layout with errors.
- Warnings — Values that are technically valid but unusual. The layout can still be saved, but review the warning before drilling.
- Info — Helpful context about what a value means or how it will affect ball motion.
Validation warnings are saved with the layout so you can review them later from the detail screen.
Free vs. Pro PRO
All four calculator methods and the Recommend My Layout wizard are available to every user. The difference is in how many layouts you can save:
- Free — Save up to 2 layouts.
- Pro — Unlimited saved layouts.
If you reach the free limit, you will be prompted to upgrade. You can still use the calculators to compute layouts; you just cannot save more than 2 until you upgrade.
Tip
Even on the free tier, you can compute as many layouts as you want. Take a screenshot of the result and marking guide if you are not ready to upgrade but need to save more than two.
Tip
Layout calculations are guidelines, not gospel. Always consult with your pro shop operator before drilling. They can verify your PAP, account for ball-specific characteristics, and make adjustments based on their experience with your game.