What Is A Bowling Ball Drilling Layout

bowlingball.com, Originally Posted: 12/3/2013; Updated: 10/5/2022

If you are relatively new to the game and are thinking about purchasing your first bowling ball, you will be faced with having the ball fitted to your hand with a selected drilling layout to be determined by the pro shop professional.


A bowling ball drilling layout is simply the map of where your pro shop pro will drill gripping holes into your new bowling ball. By drilling holes into the ball weight will be removed from the ball which will cause a slight weight imbalance toward a given side of the bowling ball.

Your pro shop professional can use this imbalance to your bowling advantage and influence the ball motion as it travels down the lane. Assuming you are developing an effective release technique with your bowling instructor, having a bowling ball to match best with your style, the lane conditions at your local bowling center, and with your delivery tangibles.

Tangibles such as your ball speed, your amount of tilt in the bowling balls rotating axis, and how many revolutions per minute you apply to the bowling ball. There are points of interest related to the surface of your bowling ball which assist a pro shop professional when it comes time to map a drilling layout.

The “Pin” represents the top part of the weight block and is usually represented by a colored dot on the surface of the ball. This “Pin” locator is best defined as a polyester or urethane stem which is positioned in the weight block to hold the core in place as the coverstock is poured into the ball mold during the manufacturing process. The Center of Gravity marking on your ball surface is another tool your pro shop “pro” uses to find the initial static balance point, when your new ball is placed on a scale to begin the mapping procedure.

If you purchase an entry level bowling ball, the Pin location is likely going to be found on or very near the CG marking on the ball surface.  Your pro shop “pro” will use these markings to create a slight weight imbalance factoring in the removed amount of weight after the gripping holes are drilled into your bowling ball. A very key factor in selecting a new bowling ball is the type of coverstock (material used in creating the cover of the bowling ball) your pro shop “pro” believes will match the local lane conditions.


Coverstocks vary primarily in the surface texture of your bowling ball and with the materials used by the manufacturer to produce a given amount of traction on the surface of the lane. It is important for you to rely on your pro shop professional to help you select the type of coverstock and match it with a select drilling layout which best suits your developmental stage to date. A properly fitted bowling ball with an appropriate drilling layout will help you get started in the game and will give you the best chances at success.