Ten Pin help needed -- Sorry if covered before.

[Mike White]

In regard to the pocket.

A 2.5 inch offset is basically the perfect strike hit for all entry angles and all ball weights. The strike pocket is approximately 17.5 boards in from the right, or the same from the left for left-handers.



Here's the pocket showing 0°-2°-4°-6° entry angles

I don't know where you got your info and images but i'd question it's validity.

First off, lets not confuse inches and "boards".

The lane is 41.5 (+- 1/2 ) inches wide, and consists of 39 "boards".
That means each board is approximately 1 1/16" inch wide.

The head pin while sitting on the 20 board, is more accurately centered at 19.5 boards from the edge of the lane, or 20.75" from the edge of the lane.

The pin diameter at point of impact is about 4.72".
The ball diameter is about 8.595"

This means at impact, the vertical center line of the pin is about 6.66 inches from the center of the ball.

Since we want to drive the head pin directly towards the 7 pin we need to impact the pin on a line 30 degrees counter clockwise thru the center of the head pin.

This puts the offset from the vertical center line of the head pin to the center of the ball at 3.33" (6.66*sin(30)) in the cross lane direction.

20.75 - 3.33 = 17.42, 17.42 / (1 1/16) = 16.4 So the true pocket is approximately the 16.4 board

[bowl1820]

I don't know where you got your info and images but i'd question it's validity.

Well the first image is mine the 2nd is is from the USBC Pin Carry Study. and the info is based on USBC info and a John Williams
(BTBA National Coach) article.

Link
http://usbcongress.http.internapcdn....CarryStudy.pdf

I'll post the question "Okay, just where is the pocket????" over at bowlingchat with both our views and see what they come up with.
http://forum.bowlingchat.net/viewtop...p=69526#p69526

The only other I can say is The head pin is centered on the 20 board and the offset is measured from the center of it, so a 2.5" offset places at approx. the 17.5 board.




--------------------------------
by John Williams
(BTBA National Coach)

"Technically, the strike pocket is measured by 'offsets', that is the distance between the centre of the ball and the centre of the head pin.

If the centre of the ball was in direct line with the centre of the head pin, then this would be called 'zero offset'.

A 2.5 inch offset is basically the perfect strike hit for all entry angles and all ball weights. If you remember my article of last December about the 'Basic Adjustment' for getting your ball into the pocket, there is 12 inches between the centre of the head pin and the centre of the 3-pin and also between the centre of the head pin and the centre of the 2-pin. There are normally 39 boards in a lane and the width is between 41.5 and 42 inches, so each board is more or less 1.076", so the strike pocket is approximately 17.5 boards in from the right, or the same from the left for left-handers."

------------------------------

Here's from Bowlingball.coms page about the pocket

The center of the pocket is located on the 17.5 board on the pindeck. Using a right handed bowler as the example, the pocket is on the 17.5 board counting from the right edge of the lane. The center of the "head pin" pin spot on the pin deck is located on the 20 board, the exact center of the bowling lane.


------------
entry angle stuff

And heres something from walter rays site with some math. (WRW has a Bachelor of Science degree in Physics and a minor in Mathematics)

A guy said "I was attempting to enter the pocket at about 33 degrees"

wrw responded:
"If you were able to get your ball to enter at a 33 degree angle into the pocket the ball would probably miss the 8 pin to the left. Unless the lane was oiled to 59 feet and you put a lot of side roll on the ball I don't think you are going to get more than 10 degrees of entering angle. The big crankers like Tommy Jones and Sean Rash can get the ball to come back from 5 at 45' on some of the PBA patterns. A little math gives a distance of 180" (60'-45'= 15*12= 180) and 13" right to left (5 to 17 board)*(14/13)= 12.9 . Take the inverse tangent of .0722 and that gives you an angle of 4.13 degrees. To get a 33 degree angle you would have to have the ball on the 9.75 board at 1 foot from the head pin. Tangent of 33 degrees is .649 which would have to equal the boards crossed divided by the distance down the lane to the pins. A board normally equals 14/13 inch (42 inches wide and 39 boards). Good luck."


---------------------
About entry angle
quote:I was under the impression that the angle was determined on how many boards the ball covered X amount of feet from the pocket. Example. If the ball covered 6 boards the last 3 feet the angle was 6.

That would be
Backend Boards Covered (BBC): This is the total number of boards covered or crossed from the breakpoint board(X) to the entry board (17)

Example: entry board (17)- board (11)= 6 boards covered.

Using WRW's forumla
The entry angle here is about 10 Degrees.
60'-57'=3'=36" from the pins
17 board - 11 board = 6 boards
6 boards*(14/13)=6.46
6.46/36=.1794
The inverse tangent of .1794 = 10.17 degrees

[dnhoffman]

Well... That about settles that, lol.

[Mike White]

Well the first image is mine the 2nd is is from the USBC Pin Carry Study. and the info is based on USBC info and a John Williams
(BTBA National Coach) article.

Link
http://usbcongress.http.internapcdn....CarryStudy.pdf

I'll post the question "Okay, just where is the pocket????" over at bowlingchat with both our views and see what they come up with.
http://forum.bowlingchat.net/viewtop...p=69526#p69526

The only other I can say is The head pin is centered on the 20 board and the offset is measured from the center of it, so a 2.5" offset places at approx. the 17.5 board.




--------------------------------
by John Williams
(BTBA National Coach)

...

------------------------------

Here's from Bowlingball.coms page about the pocket

...

------------
entry angle stuff

And heres something from walter rays site with some math. (WRW has a Bachelor of Science degree in Physics and a minor in Mathematics)

...

---------------------
About entry angle

....

First off Mr Williams.

He is inconsistent with his own calculations.
If the pocket is 17.5 board from the edge of the lane, and each board is 42/39", the pocket would be 18.8" from the edge of the lane.
Add the 2.5" offset and the center of the headpin would be 21.35" from the edge of the lane, making the lane 42.69" wide.

Second... Bowlingball.com ...
Rich Carrubba.. need I say more?

Finally Walter Ray....
WRW places the pocket on the 17th board, which is in agreement with what I've stated.
The center of the 17th board is 16.5 boards from the edge of the lane.
I stated the pocket was 16.4 boards from the edge with would also place the ball on the 17th board.

[bowl1820]

First off Mr Williams.

He is inconsistent with his own calculations.
If the pocket is 17.5 board from the edge of the lane, and each board is 42/39", the pocket would be 18.8" from the edge of the lane.
Add the 2.5" offset and the center of the headpin would be 21.35" from the edge of the lane, making the lane 42.69" wide.

Second... Bowlingball.com ...
Rich Carrubba.. need I say more?

Finally Walter Ray....
WRW places the pocket on the 17th board, which is in agreement with what I've stated.
The center of the 17th board is 16.5 boards from the edge of the lane.

Okay Mike your right and everybody else is wrong.
While your going around showing everyone your new way of locating the PAP,You might add this information along with it to get everyone up to speed. Oh and contact the USBC also so they can update also.

Let them know over at insidebowling.com too they got it wrong also:

Understanding Entry Angle
Last month we discussed the importance of entry angle for pin carry. This month, we'll look at where the ball needs to be to create that entry angle.

We have long believed, and USBC has confirmed, that an entry angle of about 6 degrees improved strike percentage. USBC studies also showed that the best strike percentage occurred when the ball enters the pins at the 17.5 board.

Below you see the trigonometric formula for determining what the entry angles really mean in terms we actually can use on the lanes. The formulas assume that each board is 1" wide (although actually each is about 1.05" wide, so that 39 of them equal the 41" wide lane surface). At the edge of the lane, the ball is 17.5 boards from the entry board. If we know how far the ball is from the pins, we can determine what board it should be on for any given entry angle.

I stated the pocket was 16.4 boards from the edge with would also place the ball on the 17th board.

Okay lets see here.

You say here the pocket is 16.4 "boards" from the edge, this places the ball on the 17th "board".

And I posted the pocket is approx. on the 17.5 board, So wow we are only off half a board now.

So we are almost in agreement!

[Mike White]

Okay Mike your right and everybody else is wrong.
While your going around showing everyone your new way of locating the PAP,You might add this information along with it to get everyone up to speed. Oh and contact the USBC also so they can update also.




Okay lets see here.

You say here the pocket is 16.4 "boards" from the edge, this places the ball on the 17th "board".

And I posted the pocket is approx. on the 17.5 board, So wow we are only off half a board now.


Or is it your inconsistent with your calculations, Remember you said " First off, lets not confuse inches and "boards"."

You said 17.5 board from the edge, which would place it on the middle of the 18 board.
You like the others seem to think that 17.5 boards from the edge plus the 2.5" offset would be the middle of the lane.

Work out the numbers for yourself. Don't assume what someone has told you in the past is true.
Especially when many of your sources are simply repeating what was told to them.

[bowl1820]

You said 17.5 board from the edge, which would place it on the middle of the 18 board.
You like the others seem to think that 17.5 boards from the edge plus the 2.5" offset would be the middle of the lane.

Work out the numbers for yourself. Don't assume what someone has told you in the past is true.
Especially when many of your sources are simply repeating what was told to them.

Sorry I updated my post above while you were posting.

Mike I had already had worked it out.

A 2.5" offset from the center of the headpin is almost right on the line between the 17 & 18 boards. If you look at the USBC pic above the 2.5"offset line with the 0° entry line is right on the line between 17&18

And like they said above the formulas used assume that each board is 1" wide. Even though they know the actual size.

Given if the center of a board is the "board", then half way between 17 & 18 would be 17 and a half board .

Did they state it the most accurate way they could? No maybe not.

They could have just said the best strike pocket for a right hander is 2.5" from the center of the headpin and left it at that. But they didn't

I also think they said 17.5 board because most bowlers would understand and visualize that easier, than saying a "2.5" offset" or x number of inches from the edge.

[Zaxmazr]

Here's how I shoot my 10 pin:



I just cant go across lane for some reason!

[Mike White]

Sorry I updated my post above while you were posting.

Mike I had already had worked it out.

You claim you worked it out..

How did you come up with 2.5"

Taking someone's word for it doesn't count as working it out.

All of the figures I presented are backed up by USBC Equipment Specifications.

The 17.5, 16.4 etc values are flexible based on the width of the lane..
At my center, they measure 41.5" but I don't assume all places measure the same.
The offset however isn't based on the width of the lane.

The lane could be 10 feet wide with no side boards.

As long as the pins were still spaced 12 inches apart at the centers, there would be a specific offset.

And I contend it would be 3.33"

I showed how to calculate the 3.33" offset, and the reason for it being the optimum location.

As far as the 1-2-4-7 is concerned, the angle of entry only varies the amount of force that is applied to the head pin, it does nothing to the direction the head pin travels.

A left hander crossing over could contact the headpin at 3.33" offset. This would create a lot less force on the head pin, yet it would still travel directly towards the 2, 4, 7.

[bowl1820]

You claim you worked it out..

How did you come up with 2.5"

Taking someone's word for it doesn't count as working it out.

All of the figures I presented are backed up by USBC Equipment Specifications.

And the 2.5" offset was shown by the USBC Pin Carry study so thats backed up by the USBC also.

Now no I didn't perform a study myself to see what offset offered the best pin carry. I don't have the cats system and all the other equipment to do a pin carry study myself.

What study did you do to determine 3.33" is the optimum location?

The 17.5, 16.4 etc values are flexible based on the width of the lane..
At my center, they measure 41.5" but I don't assume all places measure the same.

I agree and I never said otherwise.

The offset however isn't based on the width of the lane.

I never said it was.

The lane could be 10 feet wide with no side boards.

As long as the pins were still spaced 12 inches apart at the centers, there would be a specific offset.

I agree with that.

And I contend it would be 3.33"

I showed how to calculate the 3.33" offset, and the reason for it being the optimum location.

Yes you calculated a 3.33" offset, but that's not proof of it being the optimum location.

Here's from the USBC pin carry study:
It shows a 2.5" offset from the head pin had the highest percentage of strikes.

As for the 3.33" offset let's see, it decreased strikes by almost 20% and increased 10 pin leaves by the same amount. Hmmm optimum location?

As far as the 1-2-4-7 is concerned, the angle of entry only varies the amount of force that is applied to the head pin, it does nothing to the direction the head pin travels.

A left hander crossing over could contact the headpin at 3.33" offset. This would create a lot less force on the head pin, yet it would still travel directly towards the 2, 4, 7.

Yes, I agree a ball crossing over would create a lot less force on the head pin. I never said it didn't.


You know what Mike, we're not going to agree. You showed your side and Me mine. It's up to everyone else to decide who they want to go with.