Every bowler knows that each bowling ball has 3 finger holes; one for the ring finger, one for the middle finger, and a larger one below these for the player’s thumb. On occasion players have other holes, called balance holes drilled into their bowling balls to adjust the dynamics of the ball while it is moving down the lane.

The static weights of a bowling ball measure the balance of the ball. There are specifications that static weights must follow: these were set forth by the WIBC, or Women’s International Bowling Congress, and the ABC, or American Bowling Congress. The ABC says that if a bowling ball weighs 10 or more pounds, then the highest difference in weight from the top of the ball to the bottom would be 3 oz. They also say that the difference of weights from the front to the back of the ball’s finger holes is one ounce.

The same is true for the sides of the bowling ball.  As the size of the ball decreases, so do these weight limits. For a ball that weighs 8 pounds, the limit in difference from top to bottom is 2 ounces and ¾ ounces between sides. The creation of finger holes affects the weight of the top of the ball as compared to the bottom, because of the material that is removed. This affects the ball’s trajectory, or the way it travels the lane. Perfecting or even just improving the static weights of a ball can be very beneficial to the bowler for this reason.

Many times, bowlers have holes called balance holes drilled into the more heavy part of their bowling balls. This helps adjust the imbalance in weight from the top to the bottom of the bowling ball. The rulebook of the ABC says that only one balance hole may be drilled into a bowling ball. The balance hole cannot be greater than 1 ¼ inches wide. Bowlers who intend to compete in any way must be careful to follow these regulations.

Some avid bowlers may also have balance holes drilled into their balls to affect the way they hook, or curve into the pins. A ball being imbalanced in weight from one side to the other can cause a more dramatic hook. When trying balance holes for this reason, it is highly recommended that a small balance hole be tried out first, as there is not going back. Bigger holes can be drilled once the bowler figures out the effect the smaller ones have on their shots. Deeper holes drill into the core of the ball, causing a greater change in its movement. More shallow holes only remove the less dense material from the ball and will not cause nearly as big of a change. The speed that the bowler uses while rolling the ball also affects the size of hole they will want drilled. The higher the speed, the bigger the balance hole should be. 

Balance holes can be a very useful tool for more advanced bowlers, that have already worked on perfecting their shot and need a little boost in one direction or another. That being said, it is extremely important to abide by the specifications set forth by the bowling organizations, the ABC and WIBC. As long as this is done, this technique for modifying a bowling ball by drilling balance holes could bring an avid bowler’s game up that notch they have been looking for.