PAP Identification Method (& Terminology)

[kidlost2000]

I wouldn't say it's the center grip line that is the problem, it's more the Over and Up method which is based on the grip center (not the same as center grip line).

Take two bowlers who are identical in every way except in spans. The Over and Up method puts the Pin in a slightly different location based on the difference in the spans.
My system ignores the span because when the torque is applied to the ball, the thumb is already out.

I understand what your saying now because of the above statement. (i think) Yes a difference in spans will have an effect on the ball, but not exactly for why you mentioned. No ball will ever be 100% exact for two different bowlers with different spans or different other factors.(save for last)

Lets see if we can agree on a few things

1. The dual angle method uses the bowlers PAP which is measured from the center of the span to layout the ball.

2. By laying the ball out on this method for any bowler or any span or style it puts the pin and mb/psa in the exact same distance and degree from each bowlers PAP.

That we can agree on, where you see fault is after drawing the center grip line, the span will be based off the center of the bowlers span which can be 3" or 5" and there for the relation of the pin to fingers is different for each bowler? Correct?

In the pic below we have the ball laid out with a 3" span and a 5" span. I used paint to touch up the finger lines and where the mb/psa is to help see better.

006 (2).JPG


That is true the pin to fingers for each is different, but this irrelevant because even though the spans are different the pin and mb at release will be at the exact same position for each bowler based on their actual PAP. That is the key factor. So even with a 6" span, at release on the DA method the pin and mb will be in the exact same relation as the 3" 4" 5" ect span and give the bowlers the same layout in every way. The difference in reaction from bowler to bowler will be based on the bowlers style, not the ball, Example you can layout a ball on the exact DA method for Walter Ray and Sean Rash but there obviously going to have different reactions even with the same ball, but they will have the same pin and psa to PAP distance and degree at releases onto the lane.

It may not change your mind or way of thinking but you may come up with something else or modify yours to better work.

Now (the save for later part) what you can't factor in as the other concern is the dynamics that change the ball when you add holes. This is where your somewhat right. using the 3" span and 5" span when your start drilling those finger holes typically what happens is the balls low rg axis/pin shifts away from holes while the bowling balls high rg axis/ mb/psa generally shifts towards holes. When this happens you can use a determinator to spin the ball and find its new high rg axis and then draw a line 6 3/4" back through the cg to find its new low rg axis. Depending on the size of the finger holes, depth, if a weight hole is added and where will all have effects on the end result of the dynamics of the ball. I would say at that point even if all holes where drilled the same size for two different spans on the above pictured ball, the effect it has on the core will be slightly different and the end location of the high and low rg axis will not be the same even though the starting points for each span where. That being said, the effects are very small and not enough to be a determining difference if laying out and drilling a ball identical for different spans.

[Mike White]

Okay. Now, I think I understand you a little better.

Let's take your example of two bowlers with the same PAP, ball speed & Rev rate BUT the spans are different. One guy has a 3.5" span, the other has 5" span. We drill the same ball for both bowlers using the dual angle method (pick whatever angles and pin distance you want). The end results: The balls WILL roll virtually identical. Why? Because the balls are laid out identical in relationship to the PAP. The pin distance tells you how the core is positioned at release. The fact that the pin maybe further away from the fingers of the shorter span and closer to the fingers of the longer span is irreverent. (Yes the static weights could vary slightly between the two, especially if the core of the ball is close to any of the holes) The ball DOES NOT care where the force is applied. Think of this. USBC and Brunswick both have a million dollar machines they can emulate ANY style of ANY bowler, yet it has no fingers to put in the holes and uses two robotic hands). So I could throw one of my balls, and one of these robots could emulate me and throw my same ball. If you watched a video of the ball just after release, you couldn't tell where the force is being applied. If you assumed it was at my finger holes, you would be wrong for the robot. But the reactions would be identical. Where the force comes from doesn't matter. After the point of release all the laws of physics are identical.

Pin location and the bowlers PAP tell you everything you need to know. AMF used to have a video of one of their balls that showed a transparent view of the ball to see how the core worked. If the pin was placed on the bowlers PAP, the core was basically in a balanced position at release. The ball had virtually no flare and hooked very evenly. If the pin was place 3 3/8" from the PAP, the core was at its most unbalanced position. The results; the ball had maximum flare, maximum revs in the midlane and hook.

Your idea of where force is applied in relationship to the core or pin location serves no point. Dual Angle Method wins!!

ROG = Radius of Gyration???

This is so bad I don't know where to begin pointing out the mistakes.

Lets start with the robot.

Back when scores started to climb ABC (at the time) defended itself by saying that even it's robot hadn't shot 300.

Ya think maybe the robot wasn't as good as implied.

About the gripping method of the robot vs the human. I'll bet if you talked to the people who designed the robot, the core position (in terms of rotation around the axis) was an issue, but they couldn't find an acceptable solution.

If the position of the core, in terms rotation around the axis, at the point of release, doesn't matter, then what is the point of the 30, in a 40 x 3 x 30 layout?

The Pin to PAP distance only tells you 1/3 of what you need to know.

15 years? How much of that was napping?

[Mike White]

Okay just to be sure this is the flaw your talking about.
Here's two bowlers, same layout, same pap location, only the spans are different.


Why shouldn't we look at this way:
Take two bowlers who are identical in every way except in spans. The Over and Up method puts the Pin in the same location regardless of the difference in the spans.

Why does the pap have to be directly across from the fingers?

Your picture is taking bad, and compounding it with worse.

Part of the problem is visualizing the ball surface projected onto a flat surface.

A 90 degree angle on the ball isn't a 90 degree angle on the flat surface.

Example. Assume all angles are 90 degrees and each line is 6 3/4 inch long.



A......D
|.......|
|.......|
|.......|
B-----C

A, B, C, and D represent 4 different points on a flat surface.

On a sphere, points A, and D would be the same point.
To draw that on a flat surface, the angles to use would be 60 degrees.

....A
.../.\
../...\
B-----C

[Dogtown]

This will be my last post on this subject.

If you took a picture right at the point of release of a person with a 3.5" span and a 5" span (from my last example; same PAP, style, etc..), the core would be in the exact same position for both bowlers (assuming the balls were transparent for everyone to see). We know this because the pin to PAP are the same. The pin location tells you exactly where and how the core is positioned. How do we know this? Because the pin is what is holding the core in place.

The video I referred to earlier was actually from Ebonite. They sent out a video when they released their Matrix Trimax. I have tried to find this on the internet because it very clearly illustrates what I'm trying to describe to everyone reading.

Mr. White, I think you have a great understanding of math as it relates to bowling. In fact I learned something from one of your post that I had always just taken for granted. But, I think if you spend some more time on the subject, you may come to realize that the dual angle method works and works pretty well. I will say this one last time. Where torque is applied on the ball is irrelevant. Your method WILL need to account for the Sarge Easter grip, two handerd bowlers, bowlers who cuff the ball, bowlers who use 3 fingers, 4 fingers or No fingers. They make up more than the 1% you are assuming. The dual angle method does this.

Good luck!

[Dogtown]

Good job KidLost2000!! Now, I'm done.

[kidlost2000]

What DT mentioned is what others are trying to say as well. On the dual angle method even if you have 5 different bowlers, styles, and spans when the ball is released by each they will have have the same pin and mb to pap relationship. So that 45 x 3 x 30 layout will be identical at release for each bowler. The torque may be applied in a different location on the ball from one person to the next, but the core will be in the exact same position for every bowler when it the torque is applied.

http://www.youtube.com/watch?v=b-EHB...feature=fvwrel

Shows different style bowlers and there releases with their PAP marked. By using there PAP in the DA method for any bowler with the same layout based off their PAP the pin and MB will be in the exact same location no matter how the force is applied. That is irrelevant once the ball touches the lane. The torque may be applied in a different location on the ball from one person to the next, but the core will be in the exact same position for every bowler when it the torque is applied.

[bowl1820]

As I said earlier Mike, if you think there's something wrong with the system fine, I'm not going to say your wrong.

In fact since you worked it out and you won a ball here, when you take it to the pro shop to get it drilled. Have the driller use your system to lay it out and drill it.

Might take a look at at Ebonite's Blueprint software, you can input in your layout and try it out in computer sim.
They have a demo version.
http://www.blueprintbowling.com/

CAD-Powered Virtual Bowling Ball Drilling
Drilled Bowling Ball With Ball Track

Blueprint lets you try different drill patterns on your computer without ever putting a physical hole into the bowling ball. This allows you to experiment with different core orientations, balance holes, and gripping hole depths in order to achieve the desired as-drilled mass properties and on-lane ball track flare.

Additional highlights from the virtual ball drilling process include:

Calculation of the ball's as-drilled mass properties, including RGs, overall differential, intermediate differential (mass bias), static weights, and principal (minimum, maximum, and intermediate) RG axis position relative to the positive axis point (PAP).
Interactive 3D display of the drilled and undrilled bowling ball, with coverstock transparency for easier visualization of how the core is affected by the drilling; rotate, zoom, and pan the model to better see areas of interest.
As-Drilled RG Axes With RG Contour Plot
Optional overlay of the ball's as-drilled principal mass moment of inertia (RG) axes and the bowler's PAP...see how the RG axes move when the ball is drilled and how they are oriented relative to the PAP.
Optional overlay of an RG contour plot on the ball's surface...a Blueprint-exclusive feature that lets you better position the core relative to the PAP for optimal on-lane track flare.

[Mike White]

This is an overlay for two balls drilled for someone with 5" span and another with 3.5" span.
Blue dots represent the thumb hole location for each ball.
Red dots, the center of the finger holes.
Cyan dots, the center of the grip
Yellow dots, PAP
Orange dots, Pin
White dots, PSA

These are overlays keeping both the PAP, and the center of the grip aligned.

No surprise that the Pin and PSA match, however this isn't how the ball is thrown



This is the same layouts, just rotated to place the fingers at 3 o'clock relative to the PAP. This represents the release point.



As you see, with the only difference being span, the Pin, and therefore the core in located differently.

[kidlost2000]

I see one ball with the same layout, and one with what would be two different layouts. By shifting the pin you shift the core. When the two bowlers throw the first ball pictured the pin/top of the core will be at the same point of release for each bowler. When the ball is spinning around the pap off the hand the pin and mb will be in the same place for both bowlers. (3", 4" 5" ect span) When you understand that the rest will follow. By shifting the pin going off the second pic at release both balls while axis on the pap and will have the pin/top of the core, in different positions because they are not the same with your method.

Watch where the pin is on many of these vids in relation to the pap off the hand. No matter how long or short the span, the pin/top of the core, for both would be in the same location revolving around the pap off the hand. Even though it isn't the same distance from the fingers from one bowler to the next it doesn't matter because it revolves around the same axis from the same starting point for the bowlers style and span. The vid of different bowlers and layouts but clearly show where the pin is in reference to the pap onto the lane. Even with different spans the pin will always be in the same relation because of the bowlers pap.

http://www.youtube.com/watch?v=LOINRpWGrlw

[billf]

Hmmm. My doubles partner and I share equipment. We have identical spans and ball speed. We have different size thumbs but use the interchangeables. Same ball, same speed, same lane, obviously same layout, yet my higher rev rate and axis rotation nets me more of an angular, back end reaction.
The purpose of the choice of layout is to manipulate the stability of the core to produce the desired ball reaction for that particular bowler's style. Research has shown that Pin to PAP of 45 degrees (3 3/8") is the most unstable so it produces the maximum flare, maximum rev potential and maximun hook potential. I'm sure that would mean way too much ball dynamics for the majority of bowlers. Keep working it Mike but I'm fairly certain you will come to the same conclusion that the companies that have spent millions doing the research have..dual angle is the best available right now.