Entry angle
Reply With Quote
This is the simplest answer on how to calculate it.Originally Posted by edpup316
(One thing to remember about entry angle , while the 6 degree angle is considered the optimum entry angle according to the statistic's. The lane conditions are going to determine what the best angle is at that moment.)
The USBC has publicized that a pocket strike occurs at board 17 to 18 with an entry angle between 4 to 6 degrees.
For a right hander using a 6deg. entry angle.
make a 6 deg. line from the center of the head pin.
Then make a another line offset right 2 1/2" parallel to that one.
That line is the line going to the pocket.
-------------------------------------------------------------------------------
Here is all the other info about it I've collected about (I'll have to reorganized and condense this.)
The optimum angle of entry is about 6 degrees from straight-on, and about two inches to the side of center. This has been scientifically tested.
A regulation lane is about 40 inches wide, and it's 60 feet from the foul line to the center of the headpin.
Say you roll the ball straight down the lane, two inches from the center (that's about 18 inches from the gutter), for an entry angle of 0 degrees. That's a straight ball, no hook.
To achieve the optimum entry angle with a perfectly STRAIGHT BALL (six degrees), with the ball hitting a point 60 feet down the lane, at a point two inches to the side of the center of the headpin, use the following equation:
tan 6 = x / 60
60(tan 6) = x
x is roughly 6.31 feet. That's more than SIX FEET to the right of the R18-board (two inches right of the center of the lane), or to the left of the L18-board (two inches left of the center of the lane). That is WELL past the gutter, and maybe onto a point two lanes over. At the very least, you'd have to loft the ball over a lane, two gutters (maybe three), probably the ball-return subway, and onto the target lane in the perfect spot in order to achieve this entry angle.
----------------------------------------------------------------------------
And heres something from walter rays site with some math.
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."
-----------------------------------------------------------------------
also this-
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."
Edited on 2/27/2009 11:09 PM
-----------------------------------------
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
There is also
Total Boards Covered (TBC): This is the total number of boards covered or crossed from the time the ball contacts the lane to the entry board at the pins.
Alpha Angle: The combined angle movement of the ball. It is calculated using the launch and entry angles to give a total angle change or movement of the shot
I like pictures and I have some pins so I was going to layout examples in chalk but found this 
Wow!
Bookmarks