15lbs 3oz | 3-3.5"pin | 2.96oz TW. Roto Grip RST X-1 Bowling Ball. 15lbs 4oz | 3.5-4"pin | 3.73oz TW. RST – Roto Star Tour Core… 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.
