Understanding Differential: Today we are going to focus on another core variable that plays an integral role in bowling ball dynamics and performance. That value is the differential. The differential of a core is found by subtracting the lowest RG and highest RG found in the core of a bowling ball. The lowest RG is found at the pin of the bowling ball and is marked as the pin for that exact reason. The highest RG, in a symmetrical ball, will be found 90 degrees from the pin or lowest RG all arou