The Roto Grip SD-73 Classic is back. The most controversial ball in industry history is back and bowlers should be happy. The SD-73 Classic falls under the old USBC rules where a ball that was previously approved prior to the rule change is perfectly legal for all USBC and PBA regional competitions. The new USBC rules on differential define the maximum at 0.060”. The SD-73 Classic’s differential is a mega flaring 0.073” for the 15lb ball. The SD-73 features a low RG of 2.51 and can generate 9+inches of flare. The coverstock featured is the Sure Grip™ solid reactive. The weight block in the SD-73 is a high density cylinder with flip block. The SD-73 comes out of the box at 1000 Abralon which combined with this balls dark purple color makes it a stealthy looking weapon.
Upon opening the box and never having drilled the original SD-73 I was concerned by the very large differential. I can generate my own track flare and this monster had me a little worried. The pre drilling specs were 15lbs. 0 oz. with 3.46 top weight and a 3.5 inch pin. The symmetric core combined with the solid reactive coverstock was designed for medium to heavy oiled lanes. I erred on the cautious side with this ball and went with one of my favorites. A 4X4 drilling with the pin below the fingers. A weight hole was not required and I was relieved to hear this, as much as this ball should flare.
The first condition I got to audition this ball on was an older Anvilane surface with a typical house pattern. The middles had plenty of oil while the outsides were hooking except if you got the ball to the 1-2-3 boards then there was some hang area. After my first shot I knew I would like this ball. The SD-73 Classic had the exact ball motion I love, easy length for an aggressive oil ball and a smooth strong arc at the backend. This is the type of ball that you can just throw at a break point and watch it strike. Pin action was phenomenal and strike percentages were extremely high on all shots close to the pocket. On a couple of shots I had pins dancing like I was throwing with 2 hands like Osku Palermaa or Jason Belmonte. This ball made the turn from pretty much anywhere on this pattern. This cover surprised me in that it really got through the fronts well.
The second condition I used this ball on was a tournament pattern that was heavily oiled from 5-5. This pattern forced you to play straight up the gutter. I tried some other balls in my bag and they would go too long. The SD-73 Classic gave me the bounce off the gutter that I was looking for. Carry from this angle was great also. Aside from the occasional 9 pin everything else was wrecked. The surprising thing about this ball was when the pattern broke down I didn’t have to put it away. I just had to move my feet left and keep a similar break point.
Bowlers of all styles will love the SD-73 Classic. By the way it is also very underrated as I don’t see many players in the WNY area using it. They really don’t know what they are missing. Superb carry, great ball movement and versatility are all adjectives to describe this ball. Don’t let the high differential scare you away. Drill one now, you won’t be disappointed. Many thanks to Dan Smith from Roto-Grip, Steve Hocking of the National Bowling Store and Bob Hodge of Parkway Lanes, St Catharines.