I knew I'd posted something on asb about this but I didn't realise how long ago - from 1988 on alt.sport.bowling...
"Time for me to inflict my opinion on the ng. again
Warning - this is
a somewhat technical post that will probably do exactly nothing for most
bowlers. You have been warned.
I have seen offsets drilled at least three ways. One way alters the
finger pitches VERY slightly, one alters finger pitch and span, and one
alters finger (a little) and thumb (a lot) pitch and spans. IMHO, all
three method arise through not understanding the reason for putting
lateral pitches on the fingers.
Everything below assumes a RH drill, BTW.
Method 1 involves drawing a grip 'centreline', then marking the thumb
position offset to this line by some amount (say 1"), and drilling the
thumbhole with correct pitch (thumb in line with where the fingers will
be). The fingers are then measured out from the thumb, the grip rotated
on to the 'centreline' (offsetting the thumb) and the fingers drilled
relative to the centreline. Obviously this does not affect the thumb
pitch. Any forward pitch in the fingers is slightly rotated (relative to
the 'true' grip centreline) to give a little more right pitch (or less
left pitch) in the fingers.
Result - the pitch change 'points' the fingers a little more towards the
inside of the hand (if they were drilled with forward pitch) and helps
the hand sit a little flatter on the ball. If the thumb is drilled by
rotating the centreline to the right (thumb not in line with where the
fingers will be) the thumb pitch will be affected very slightly
depending on the size of the pitches drilled (a zero - zero thumb will
not be affected at all - 3/8 reverse puts about 1/64" 'extra' right
pitch on the thumb)
Method 2 involves drawing a grip 'centreline', then measuring out BOTH
the thumb and fingers on the centreline. After setting up the thumb
pitches, the driller then rotates the ball the desired amount to get the
offset,, and drills the thumb. The fingers are then drilled along the
marked centreline but WITHOUT REMEASURING THE SPANS! Again, this has
little or no effect on the thumb pitch, and has the same effect on the
finger pitches as method 1. It also lengthens the ring finger span
slightly (usually the middle finger is unaffected, except for large
offsets).
Result - as for 1, the pitch change 'points' the fingers a little more
towards the inside of the hand. The longer ring finger span 'pulls' the
grip around anticlockwise, sitting the palm flatter on the ball. Major
candidate for problems at the base of the thumb and ring finger
tendonitis, IF the original span was correct. In some cases, this
'offset' will unintentionally correct a short ring finger span,
especially in bowlers with very flexible hands.
Still no advantage over a _correctly_ fitted grip, BTW.
Method 3: As for 2, except that instead of ROTATING the ball to get the
thumb offset, the driller cranks it over with the pitch setting lever.
Result: the ball now has too much left pitch by whatever the offset
distance was, and wrong spans. I have only seen this 'method' once. Nuff
said.
Now for the 'why it works' bit. Hold your hand in front of you, palm up.
bend the middle two fingers inwards a little, preferably with a pencil
or something between them to represent the bridge. Where do they point?
For most people, they will _not_ point directly at the base of the
thumb, but somewhere to the left towards the middle of the palm. They
will also point somewhat towards each other, rather than being parallel.
This shows the need to have correct SIDE pitches in the fingers - to
'point' the fingers in the direction they naturally want to. Many ball
drillers ignore this - the finger pitches are established by pointing
the drill on the centreline of the bridge, and cranking the ball
sideways with the pitch settings to the right place. This puts about
3/4" left and right pitch on the middle and ring respectively, but more
importantly it points the fingers right at the base of the thumb! The
ball driller will tell you he has put zero-zero on the fingers, when he
simply hasn't a clue how to drill correct finger pitches. Offsetting the
thumb, in this case, reduces the error.
Any grip can be reproduced on a straight up drilling with correct spans
and pitches. Offsets, like other similar grips such as the Strickland
grew up as a way of correcting for errors that the early drillers didn't
even know they were making.
Good ball drillers are hard to find. Be nice to them.
Rob."
I'm REALLY getting old...
