Proper Fitting Bowling Ball Thumb Hole
It is extremely important in good shotmaking to use a proper fitting bowling ball thumb hole.
Thumb holes which are either too loose or too tight and not shaped or contoured to form fit to your thumb will certainly invite errant deliveries.
It is the duty of the pro shop professional to custom fit your bowling ball to fit your hand. The thumb hole is as important, if not more important, than any gripping hole or the overall span and finger pitches of your ball.
It is surprising how many bowlers will use a ball with far too much looseness in the thumb hole and then squeeze the ball in order to not drop the ball before the right time for the release to happen.
Thumb holes can be too loose if they are not contoured to fit the shape of your thumb. Rarely are bowler’s thumbs perfectly round so it is necessary to shape a thumb hole to custom fit the thumb for drilling.
Oval type thumb drilling are a good way for the pro shop pro to begin. After the hole is drilled into the ball, the pro shop pro can then shape the hole to form fit your bowling thumb.
Not only is the top of the hole in need of contouring or beveling to round off the sharp edges, the interior of the thumb hole needs to be contoured evenly throughout the entire depth of the hole.
If the hole is tight halfway down the hole but loose and larger near or at the top of the ball, the hole will not properly fit your thumb and your release will suffer from consistency.
The flat portion of your thumb (top of the first knuckle joint to the back of the knuckle) is not as wide as the side to side portion. The hole must be contoured evenly throught the entire depth of the hole to ensure you do not have to squeeze the ball just to hold onto the ball.
A properly fitted thumb hole allows you to use a tighter fitting hole than a loose one and still get out of the ball cleanly and quickly during your release.
Avoid bending your knuckle down inside the hole but rather use equal gripping pressure on the length of your thumb behind the knuckle. If your hole fits properly, you can actually relax your thumb and use very little gripping pressure to hold the ball and make an effective release.
If you have questions about the fit of your thumb hole, get into the pro shop and have the professional examine your hole and your thumb to determine if any alterations to the thumb hole is needed.
A proper fitting bowling ball thumb hole is critical to consistent shotmaking and to good scoring.
Take time to make sure each bowling ball you own fits your thumb in the right way so when you make a switch to another ball during competition, it does not cause a loss in making good shots.