How to Customize Bowling Ball's
Everyone knows that a bowling ball has three holes
-- one for the middle finger, one for the ring finger, and one
for the thumb.
But sometimes, one opening called the balance hole is
drilled into a bowling ball to facilitate the adjustment of the
ball's static weights so as to customize the ball's dynamics
when it is in motion.
A bowling ball's static weights are measurements of the
ball's balance. The American Bowling Congress (ABC) and
the Women's International Bowling Congress (WIBC) set certain
specifications of these weights.
According to the ABC, for a ball weighing 10 pounds or more,
the maximum difference between the weight of the top and the
weight of the bottom of the ball is 3 ounces, and the maximum
difference between the sides to the right and left of the
finger holes, and between the front and back of the finger
holes, is 1 ounce.
These limits decrease along with the weight of the ball, as
the limits for an 8-pound ball are a ¾ ounce differential
between the sides and a 2-ounce differential between the top
In many cases, the drilling of finger holes creates a
difference in weight, as a certain amount of material is taken
out of the ball to make room for the bowler's fingers.
This imbalance affects the way the ball moves down the lane, so
perfecting the ball's static weights can give the bowler a
To adjust this imbalance in weight, often a bowler will
drill a balance hole in the heavier part of the ball to remove
some material in an attempt to equalize the weight of the top
and bottom of the ball.
The ABC rulebook states that only one hole can be drilled
for balance purposes, and this hole cannot exceed 1¼ inches in
diameter, so bowlers must be careful not to exceed
specifications, especially if they have any plans of competing
in sanctioned events.
Bowlers also drill balance holes in their bowling balls to
affect the way the ball hooks, or curves when thrown a certain
way. An imbalance in weight from side to side can cause
the ball to curve more dramatically in order to hit the pocket
at a better angle. It is recommended that a bowler start
with a small balance hole to see what kind of effect it has on
the movement of the ball, as a deeper hole can always be
For a more dramatic reaction, balance holes should be
drilled 2½ to 3½ inches in depth, as it is at this level that
some of the ball's core will be removed which will better
affect the movement of the ball.
If one drills a shallower hole, the material that is removed
will be less dense, and this will not affect the overall mass
of the ball as much.
In addition, the speed at which one throws the ball will
also determine the suggested size of the balance hole.
For a slower ball speed, a smaller balance hole is recommended,
while a bowler who throws the ball at a high rate of speed
would best be served by a larger balance hole.
For advanced bowlers who are able to finesse the ball down
the lane with a good deal of accuracy, the balance hole is one
tool that can be used to affect the dynamics of the ball as it
moves down the bowling lane. As long as they are careful
to not exceed the major bowling organizations' specifications
on weight differentials and the amount and size of the balance
holes, bowlers are free to use this equipment customizing
technique to their advantage.