The way the finger holes are arranged on the ball surface
changes the core dynamics; this will change how the bowling ball
hooks down the lane.
There are three different types of bowling grips for bowling
balls: conventional, semi-finger tip and finger tip; all other
grips of any name (i.e., Sarge-Easter grip, etc.) are
derivatives.
In a conventional grip, the bowler's ring and middle fingers are
placed into the ball up to the second joint, while in a finger tip
grip the ring and middle finger holes are made to accept the
bowler's fingers only up to the first joint. Beginner bowlers will
start with the conventional grip, as it allows for the bowler the
maximum grip on the bowling ball without feeling like he's going to
drop the ball.
Semi-finger tip has the bowler placing his fingers between the
first and second joints. This grip is of choice for bowlers who
want a clean release of the fingers, but also want maximum control.
It also generates less hook, as strokers preferred this type of
grip. Brian Voss was one of several professionals who used the
semi-finger tip grip.
A finger tip grip requires more strength, but allows the bowler
to release the ball with more lift, and a cleaner release, giving
him more control in how the ball rotates after it is released. Don
Genalo, a former professional bowler, used the finger tip grip, but
would also place his pointer and little fingers very close together
with the other two, allowing his hand to stay behind the ball,
while allowing his unusually long fingers to maximize the lift upon
delivery.
Sarge-Easter Grip - The Sarge-Easter bowling grip prevents the
bowler from putting a heavy side spin on the ball and instead
creates more forward rotation of the ball. If you tend to put too
much spin on your ball this grip might be the perfect choice. The
thumb hole remains the same, but for this grip the middle finger
remains at finger tip depth and the ring finger is drilled to the
two knuckle depth. The amount of hook using this grip will be less
than the fingertip grip.
USBC regulations also allow for up to five holes to be drilled
on a bowling ball - with the idea that a bowler can use all five
digits to grip the ball.[5] Some bowlers use only the middle and
ring fingers, while leaving out the thumb, such as in the case of
Jason Belmonte who uses the two-handed method.
Finger Inserts:
http://www.viseinserts.com/
http://www.turbogrips.com/products.php
Useful Sites:
http://en.wikipedia.org/wiki/Bowling_ball
http://members.tripod.com/Tips_4_Ten...p_and_roll.htm
http://usbcongress.http.internapcdn....l_WEB_2009.pdf
http://ezinearticles.com/?Grip-Tips-...ing&id=2023910
http://www.brunsnick.com/sarge_easter_grip.html