Note: This article reflects my personal interpretation of 2LS. I’m not affiliated with Storm. Some of this is reasoned speculation — take it as one practitioner’s analysis, not official documentation.
Most articles about 2LS focus on how to use it. This one is about why it exists at all — because if you understand the problem it was designed to solve, the system suddenly makes a lot more sense.
There are two problems. Most people only know about one of them.
Problem 1: The Balance Hole Ban Changed Everything
If you bowled before the USBC rule changes around 2020, you probably remember balance holes. For thumbless and two-handed bowlers, a balance hole was not a gripping hole, but in terms of ball dynamics, it could serve a similar function to the thumb hole in conventional drilling: it gave the driller another place to remove material from the lower part of the ball.
When you drill a bowling ball, you’re not just creating grip holes. You’re removing material from specific areas of the core, and that changes the ball’s post-drilled differential.
Traditional layout systems assumed that material would often be removed from two general areas:
- The head — near the PIN
- The belly — near the CG and mass bias
Drilling in both areas helped keep the post-drilled differential more predictable. The core was being carved from multiple reference points, which meant the finished ball’s flare potential was easier to anticipate.
With the balance hole ban, two-handed and thumbless bowlers were left with only two finger holes — both usually drilled near the top of the ball, closer to the PIN. The lower part of the ball often goes untouched.
This creates a specific problem: when you only remove material near the finger area, the drilled ball may lose more differential than the layout on paper suggests. Depending on exactly where the PIN lands relative to your grip, that drop can be significant — making the ball behave very differently from what the original layout concept implied.
The goal of 2LS, as I understand it, is to give two-handed and thumbless bowlers a better way to control post-drilled differential. Instead of assuming that the ball will behave like a conventional layout after drilling, 2LS uses the PIN-to-COG distance to predict whether the drilled ball is likely to retain, lose, or increase dynamic strength.
That is why 2LS is not just a different way to describe pin position. It is a different way to think about what drilling actually does to a two-handed or thumbless ball.
The Key Measurement: PIN to Center of Grip
Traditional systems — Dual Angle, PAL, and others — calculate layouts primarily from the PAP outward. They define where the PIN and mass bias should land based on your PAP location, expressed as angles.
2LS shifts the reference point. The central measurement in 2LS is:
PIN-to-COG distance — the distance between the PIN and the center point between your two finger holes.
The threshold is 3-3/8 inches (approximately 85mm, or 8.5cm).
In practical 2LS language, the 3-3/8 inch point is often treated as the dividing line between pin-up and pin-down behavior.
- If the PIN is farther than 3-3/8″ from the center of your grip → pin up
- If the PIN is closer than 3-3/8″ from the center of your grip → pin down
This matters because that threshold is where ΔRG behavior shifts. Too close, and you’re drilling into the head in a way that flattens the differential more than intended. Too far, and the dynamic changes in the other direction.
If you have existing balls, grab a ruler and measure your PIN-to-COG distance right now. If a ball you thought was pin-up measures under 3-3/8″, or a ball you thought was pin-down measures over — that mismatch may explain reactions that didn’t behave as expected.
Problem 2: PAP Variability in Thumbless Bowlers
This is the second problem, and I think it’s often underappreciated.
Traditional layout systems are built on the assumption that your PAP is stable and measurable. For a conventional bowler with a thumb hole, this is largely true. The thumb anchors the release, which keeps the axis point fairly consistent from shot to shot.
For thumbless and two-handed bowlers, the PAP is less stable. Without a thumb, there’s more variation in hand position at release. Ten thumbless bowlers would show more spread in their PAP measurements than ten conventional bowlers. Even within a single session, fatigue or lane conditions can shift where the ball actually exits the hand.
The deeper issue: traditional systems derive VAL angles (and other layout angles) from the PAP. If the PAP measurement has more variance, the angle calculations inherit that variance — and angles amplify small errors more than distances do.
My interpretation is that 2LS was also designed with this in mind: by abandoning VAL-angle calculations from PAP and switching to a distance-based reference, the system becomes less sensitive to PAP measurement error. You’re working in inches, not degrees. A small shift in your actual release point doesn’t cascade into a wrong angle that puts the PIN in the wrong quadrant.
Who Actually Benefits from 2LS
This is important: 2LS is not for everyone. Treating it as a universal upgrade is a mistake.
If you’re already drilling pin-up layouts with high differential and getting the reaction you want, 2LS may not change much for you. You’re already in a position where ΔRG is staying healthy after drilling.
The bowlers most likely to see a difference are:
- Those who have tried pin-down layouts and found them inconsistent or weaker than expected
- Those whose PAP tends to produce PIN-to-COG distances that fall in an awkward range under traditional drilling
- Those who have switched to thumbless drilling and noticed that balls that once worked well now feel different
If you measure your current balls and find that your supposed pin-down layouts are actually measuring over 3-3/8″ to the grip center, that’s a signal that the existing framework isn’t reflecting your actual ball motion — and 2LS may help.
A Practical Starting Point
Storm released a reference poster with six numbered layout examples under the 2LS framework. These are useful as a starting point, but I want to be clear: the poster layouts are reference points, not the system itself.
Understanding why 3-3/8″ is the threshold, and why PIN-to-COG is the right reference distance for two-handed drilling — that’s the system. The specific number combinations come after.
My own preferred layouts (with the last number being the PIN-to-COG distance):
| Layout | Numbers |
|---|---|
| High pin | 5 × 4½ × 6 |
| Pin up | 5 × 5 × 4 |
| Pin down | 5 × 4½ × 2 |
If you’re new to 2LS, I’d suggest starting by measuring what you already have. Know whether your current balls are truly pin-up or pin-down by the 2LS definition — not just by where you intended the PIN to land.
Further Reading
For how to actually mark and drill a ball using 2LS: How to Use 2LS for Two-Handed Bowlers
For specific layout examples with reasoning: 2LS Layout Examples
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