Under USBC/ABC/WIBC rules how many gripping holes may a ball have?
A bowling ball may not have more than five holes for gripping. The USBC/ABC/WIBC Equipment Specifications further state: “The following limitations govern drilling holes in a ball: 1. Holes or indentations, not to exceed five, for gripping purposes. 2. One hole for balance purposes, not to exceed 1-1/4 inch in diameter. 3. One (1) vent hole to each finger and/or thumb hole, not to exceed 1/4 inch in diameter. 4.