Thoughts on PAP measurement (esp. no-thumb)

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dmsarch
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Joined: June 19th, 2016, 3:32 am

Thoughts on PAP measurement (esp. no-thumb)

Post by dmsarch »

I've always been bothered by how we express PAP measurements with a vertical component, rather than as a simple distance from grip center to PAP, and the grip center line being rotated around that grip center to reflect the bowler's individual anatomical and release characteristics. For folks with very small vertical PAP coordinates it doesn't make that much difference, but for those with large vertical PAP coordinates it introduces a huge heuristic distortion to visualizing a layout. What we're really trying to do with a layout is orient the core to a single line - the initial spin axis at the release. How that's achieved by the bowler's grip characteristics, hand shape, technique, etc are entirely irrelevant. The only thing that matters from an engineering standpoint is WHERE the center of grip is relative to the PAP and it's angular orientation to the core, not the grip center line's rotational orientation on the surface of the ball.

Here's my idea for laying out a ball... As applied to a no-thumber:

1. Select a desired dual-angle layout based on the bowler's preference.

2. Draw the layout on the ball as you normally would; Drill angle, pin-to-pap, VAL angle with VAL line. PAP location is now established.

3. Draw a line perpendicular to the VAL from the PAP toward the grip center. This line will represent the hypotenuse line of the bowler's horizontal and vertical PAP coordinates, and will be the PAP-to-Center Of Grip (COG) distance. This is what Storm calls the 'Lightning Arc'... A hokey marketing term for something that's actually meaningful, and that we should really understand more intuitively.

4. By construction, calculation or chart, find the length of the bowler's PAP hypotenuse. Mark this distance from the PAP to find the COG on the ball along the PAP-to-COG line.

5. From the PAP, swing an arc representing the bowler's vertical (up or down) PAP coordinate.

6. Draw a line from the COG point to tangent the PAP vertical coordinate arc. This line will be the Mid-line of the grip, and the finger holes will be drilled centered on this line.

7. Draw a line perpendicular to the Mid-line at the COG to mark the Grip Center Line, and establish the bridge width from this line.

What this does is establish the TRUE, straight-line, PAP to COG distance perpendicular to the VAL, with the finger holes rotated around the grip center to harmonize with the bowler's unique anatomical characteristics when releasing the ball. What we call the 'VAL' is not really perpendicular to the bowlers initial spin axis when we start using up or down measurements to establish the grip center on a ball (unless the bowler's vertical PAP measurement is zero). The more up or down the vertical component of the PAP measurement is, the more distortion of the VAL-to-PAP line angle it creates. This is of particular note for no-thumb bowlers who can have rather extreme up or down vertical measurements for the PAP using the conventional measurement method.

This method could work equally well for no-thumb OR thumb-in bowlers, and allow us to specify layouts in dual angle language with no caveats or changes in methodology based on the grip style.

As a further topic for research, I'm curious how the grip rotation might relate to the CLT measurement. Ultimately, I think it would be better to express PAP measurements with a single lateral distance, then a rotation around the COG measured in degrees of arc to establish the grip's mid and center lines.

I don't know if I'm the first to have thought this through... Probably not. But, I think it's worth thinking about. I believe this is one of the problems Storm has tried to work out with their 2LS layout methodology, which I feel is a little clumsy and counterintuitive. Looking at the problem as stated above makes a lot more sense to me mentally when thinking about how I want to orient a core to the initial spin axis.

Lastly... Why do we measure a thumb-in bowler's PAP from the point mid-way between finger and thumb hole edges? Since the ball is actually released and rotated by the finger tips, it seems sensible to relate the PAP to the center of the bridge between the fingers (or the pad edge of the holes?), doesn't it?

What do you all think?
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