Bowling Ball Balance Holes Increase or Decrease Ball Reaction

bowlingball.com, Originally Posted: 1/4/13; Updated: 4/13/21



**2021 Update: Per USBC Official Rules, balance holes in bowling balls are now considered illegal and must be plugged in order to be used in USBC sanctioned events. For more info, please click here. **

A balance hole is an extra hole (balance hole or weight hole) in a ball which is used to establish static balance as per the guidelines of the United States Bowling Congress (USBC) specifications. A balance hole can increase or strengthen the ball reaction or decrease or weaken the ball reaction. Working with an experienced pro shop professional is your best bet when making a decision on drilling a balance hole in a new bowling ball or adding one to an existing ball.

The effect of static weights is extremely minimal but the non-gripping balance hole does alter a ball's dynamics; those forces affecting the ball when it is in motion. Adding a balance hole is an effective way to alter a ball’s reaction while in motion. Using a balance hole on a new drilling is another way to control the ball motion based on the layout selected and the bowler’s delivery technique.

A balance hole can create a stronger ball reaction or a weaker one depending on the drilling layout and the ball construction. The location of a balance hole with regard to the distance from the pin and the bowler’s Positive Axis Point (PAP) in a bowling ball is the primary tool the pro shop professionals use for altering the bowling ball core dynamics.

Factors to consider when planning the use of a balance hole are the size of the hole, the depth it is drilled into the bowling ball, and the placement of the hole. All of these determine how the ball dynamics can be altered to produce a specific ball reaction.

The United States Bowling Congress (USBC) states that a bowling ball may have no more than one (1) ounce of side weight after the holes are drilled, among other specifications. You need a DoDo scale to weigh the ball for "side weight".

If you are over one (1) ounce (we recommend using 3/4 ounce) then the ball driller must refer to a ball weight removal chart which will help determine what size drill bit is needed, and how deep to drill the hole. By the way, the maximum allowable diameter of a balance hole is 1-1/4" for USBC sanctioned play.

Often times experienced bowlers will drill a ball and then add a weight hole to alter the dynamics of the ball while it is in motion. Ball motion control is the objective of any bowler looking to create consistent ball reaction. Use of the balance hole is one tool to help achieve bowling ball motion control.