With the re-launch of Bowling This Month, April 2014, I wrote about the new and improved Tiered Oval Process Version 3 thumb. TOPS3 will improve your swing and release. TOPS3 is a significantly comfortable thumb shape option as well. The process is designed to create a more anatomically correct shaped thumb designed to avoid bending the thumb.
CLICK HERE for the DETAILED OVAL CUT CHART
DRILL BIT SIZE to DIGITAL CONVERSION TABLE