Professional bowlers like to see continuous motion down lane with minimal deflection as the ball enters the pocket due to their rev rates usually being on the higher side. This logic was the basis of development by the R&D team as they looked to create a core that would maintain dynamics after drilling in order to maintain a higher level of core torque down lane. The larger mass at the base of the core does indeed create that. Especially since when drilled, the thumbhole will always end up in the void area not really affect the bottom mass of the core. Thus, making this core a “Tour Level” type core design better known as the Roto Star Tour Core (RST™ Core).