How does surface and weight holes affect ball motion?

How does surface affect ball motion? – Phil Hanna, Detroit Michigan

 Josh Blanchard – “"This is a question that should be asked more by bowlers who want to take fewer balls to tournaments but compete at a high level. Surfaces effects how early or late a ball start hooking on the lane. When there is more surface it will slow the ball down sooner and tend to hook earlier. When a ball has polish or less surface, the ball will travel further down the lane before it makes its motion back to the pocket."

Craig Spencer – “USBC did a ball motion study and determined that the cover determines around 60% of the ball motion, which involves the cover stock material and surface. It’s common for bowlers to have a new ball hook too early, or go too long and accidentally believe the problem is the layout. This is almost never the case. Try changing your surface and either adding polish or sanding it. It’s also important to remember that the friction and oil the ball encounters on the lane will force the surface closer and closer to 2000-3000. Because this is the finish that the lane and bowling ball tend to venture towards, the further you go away from this finish, the faster the finish will change. For example, if you go to a really low grit, that low grit won’t last very long and the ball will “shine up” even faster. It will take the ball longer to get to that 2-3000, but the ball’s performance will vary even more from frame to frame because of the amount the surface is changing as it goes down the lane and picks up oil. This is also true for super shiny balls with a lot of polish, the shinier you make it, the bigger difference you will see between games as it dulls down and heads back towards that 2-3000 mark.

How does a balance hole effect ball motion? -  Paul Williams, Brighton Michigan

Josh Blanchard – “Weight holes or balance holes are used to not only make the ball legal, but it changes the dynamic of the core shape. If you drill a weight hole shallow and bigger, you will tend to see smaller difference in ball motion. When you put a smaller and deeper weight hole in a ball, you will see the ball motion change because you now changed the shape of the core as it is rolling down the lane."

Craig Spencer – “It affects it by changing the shape of the core. Many times, bowlers see a huge hole and freak out, or feel at ease when it’s a tiny hole. It’s actually the opposite, the bigger shallow hole does less to ball motion, and the tiny deep one does more. This is because as the hole is deeper, it removes core and changes the core numbers. As long as the hole is at least 3-1/2” or more from the pin, the deeper holes increase overall differential which causes the ball to hook sooner and in most cases, more. Something that we still hear a lot about in shops is side weight, finger weight and thumb weight. These are called static weights and used to be huge impacts on ball motion. Now, due to technology, they have less than 5% impact on ball motion according to the same USBC research study I mentioned in the previous question. Balance holes still affect ball motion, not because of static weights, but because of core dynamics.