Locator Pin Position
When bowling balls are manufactured, the core of the ball is suspended in the mold by a plastic colored rod. The coverstock is then poured around the core. The plastic rod is then sliced off at the ball, leaving a bright colored dot on the balls surface about one-half inch in diameter. This dot is referred to as the Locator Pin, or just the "pin," and represents the location of the center of the core. By putting this pin in different positions when drilling a ball, you can achieve different ball reactions because the core will be aligned and will rotate in a different way. As stated at the beginning of this document, the location of the pin controls what the ball does in roughly the first 40 feet of the lane. It controls when the ball will change direction, how much the ball will flare and how much hook potential it will have when it does change direction.
There are generally four directions you can place the pin: high, low, towards the PAP and towards the track, or combinations thereof.
High pin position
A "high" pin position means that the pin is located up towards the top of the ball. The higher the pin is placed, the longer the ball will go down the lane before it changes direction. One must be careful, for if the pin is placed too high, the ball will go too long and will change direction too late, if at all.
Low pin position
A pin located towards the midline (horizontal line midway between thumb and fingerholes - use to locate PAP), or even lower, will make the ball change direction earlier. It is also important to note that if the pin is placed too low, the ball might flare or track over the middle finger. There is something called "the safe zone" which is located above an imaginary line from the PAP to the middle finger. If the pin is placed below this line, there is the danger of the flare hitting the middle finger. If the pin is above this line, the ball is "safe" from this result. Generally, this is only a problem for higher-track players and for high flare potential bowling balls.
Pin towards the PAP
The closer the pin is placed to the bowler's positive axis point, the earlier the ball will change direction. Please note this does NOT necessarily mean the ball will hook more - only earlier. There are ways to drill balls involving this method where balls will change direction earlier than most other equipment, but cover less total boards than most other equipment.
Also, a pin on the PAP will generally make the ball have zero flare potential. This is because the core is in a very stable position. Flare is caused by the core "realigning" itself in order to find a stable position to roll in. A ball with the pin on the axis means that the core is laying exactly on its side and rolling much like a rolling pin that a chef would use to flatten out dough. Again, this is a very stable position so the core has no work to do to find stability.
Pin towards the track
The closer the pin is placed to the bowler's track, the later the ball will change direction. This is essentially the opposite of the previous description of the pin near the PAP regarding when the ball will hook.
However, this is very much like the pin towards the PAP regarding flare potential. Pin on the track is also a very stable position. The core is standing straight up and down relative to the axis on which it is rotating. Because of this stability, the ball again will not flare much because it has no reason to find a more stable position...it is already in a very stable position.
Pin between PAP and track
Although not an actual, physical "location," the vast majority of bowling balls are drilled where the pin is near the middle of these two. If you put the pin at about 3 3/8" from the PAP, this results in a ball which has the core in a very unstable position. The core is not laying on its side and it is not standing up either. As a result, it will try to realign itself during its trip down the lane to find some stability. This is what causes track flare, and the 3 3/8" pin position cause a LARGE amount of track flare because the pin will be about halfway between the track and the PAP. The further from this 3 3/8" point you get, the less the ball will flare. Going towards the axis will make it flare less and hook sooner...going towards the track will make it flare less and hook later.
Now you are starting to get the idea of how to "tweak" the pin position to accomplish the reaction you desire. With combinations of vertical and horizontal pin location, you can make the ball do just about anything on the front 2/3 of the lane, which dictates how much hook potential it will end up having when it gets to the last 1/3 of the lane.
One note about pin position - Please notice how I prefer not to refer to pin placement relative to the bowler's ring finger, middle finger, etc. The term "pin above the ring finger" and all others like it are totally meaningless. Keep in mind that bowlers have different PAP's and different spans (distance between thumbhole and fingerholes). A bowler with a pin above his ring finger can get a totally different reaction than someone else, and the pin can also be in a totally different place on the ball depending on the length of the bowler's span. When referring to pin placement, please try to refer to it as a distance from the PAP and also how far above or below the midline.
You can go to this site for more also.
http://www.bowlingfans.com/jeff/ballreactionbasics.html--------------------------------------------------------------------------------
Edited on 5/20/2004 7:36 PM
