Ball Drilling Specifications – A Reminder

The BTBA would like to remind our members that the Rules regarding Ball Weight and Drilling which were highlighted in last years AGM publication come into place as of August 1st 2020.

This is an extract from the 2019 AGM document, and we have included it as a reminder of the changes taking place 1st August 2020– please note that this change is mandatory – no exceptions.
Please ensure that your bowlling ball(s) is/are correctly  prepared ahead of the 1st August 2020 deadline date and consult with your professional.

11.12 Drilling specifications 

11.12.1 The following limitations, as specified, shall govern the drilling of holes

11.12.2 Holes or indentations for gripping purposes shall not exceed five and shall be limited to one for each finger and one for the thumb, all for the same The player is not required to use all finger holes in any specific delivery, but they must be able to demonstrate, with the same hand, that each gripping hole can be simultaneously used for gripping purposes. Any thumb hole that is not used for gripping purposes during the delivery would be classified as a balance hole.

11.12.3 (until August 1, 2020), One hole for balance purposes not to exceed 1 ¼ inch (31.8 mm) (Including the surface opening).

11.12.4 No more than one vent hole to each finger and/or thumb hole not to exceed ¼ inch (6.4 mm) in (Including the surface opening).

11.12.5 One mill hole for inspection purposes not to exceed 5/8 inch (15.9 mm) in diameter and 1/8 inch (3.2 mm) in depth

11.13 Balance

11.13.1 The following tolerances shall be permissible in the balance of a bowling ball used in sanctioned

11.13.2 Weight more than 10 pounds (4.53 kg) a) Not more than 3 ounces (85 grams) difference between the top half of the ball (gripping holes side) and the bottom half of the ball (side opposite the gripping holes)

b) (not valid on or after August 1, 2020), Not more than 1 ounce (28 grams) difference between the half of the ball to the left and the half of the ball to the right of the center of grip (side weight). 

c)  (not valid on or after August 1, 2020), Not more than 1 ounce (28 grams) difference between the half of the ball toward the thumb hole side of the center of grip and toward the finger holes side of the center of grip (thumb/ finger weight).