Asymmetrical vs Symmetrical Core, What to Choose ?
Asymmetrical vs Symmetrical core? We see the core constantly in the description of the hook bowling balls defined as such, but what is the difference of the two?
An Asymmetrical ball is where the RG (radius of gyration) differential between the high and low axes differ by more than 5%.
To keep it in simple terms that do not involve the ratio of gyration, the Asymmetrical core is not in equal proportions top to bottom where as the Symmetrical core is.
The Symmetrical core is normally longer, slimmer, more consistent profile. I know this is an over simplification, but if you look at different cores you will see what I mean when I say that. These are just examples, and many different styles are made.
Here is how Wikipedia describes asymmetry
If you notice above the Asymmetrical Core has a varied assortment of protrusions in different areas that are in an irregular shape, where as the Symmetrical Core is more uniform in respect to the ball, or basically in the same proportions all the way around the ball.
Because the proportions in the Asymmetrical are not uniform, the weight distribution when you hook your bowling ball, will cause a sharp angle to occur when the ball reaches the break point and will respond faster to friction on the lane compared to the Symmetrical Core.
It is producing a controlled off-balance situation which enhances the bowling balls hook, and changes the angle of entry to the pocket.This angle is changed when the axis of the ball moves in response to the core weight being affected by the friction of the lane.
Also known as the flare potential of the ball, the higher the differential of RG measurement number, the greater the track flare potential.
Asymmetrical cores in general will give you more skid length before beginning to hook, but will hook harder and stronger, sometimes referred to as the block flip.
When the ball reaches the break point, the direction changes abruptly as the weight block flips or starts to affect the balls direction of travel.
Who Would Want an Asymmetrical Ball?
The needs of the bowler come into play, when you talk about what a bowler needs.If a bowler thinks that his ball needs more hook, then he is more likely to pick an Asymmetrical core, to help the ball finisher stronger.
If a bowler is having problems with his ball hooking too soon and feels he needs to get the ball further down the lane, then he also might turn to the Asymmetrical ball, with a less aggressive cover stock.
Why? This will provide the additional skid to get the ball farther down the lane. But, in heavy oil conditions, then a more aggressive cover stock, combined with the weight distribution of the Asymmetrical block, give you the most aggressive angle hooking balls.
If you were league bowling and into the third game and were having issues with control or heads that were just to dry, then this is the condition where the less aggressive Asymmetrical ball would work too your advantage.
What is a Symmetrical Core?
To clarify we are talking about cores here, and non-drilled balls. Because once the ball is drilled for fingers and thumb holes, then all balls become Asymmetrical to a point, and the differential of + or – 5% becomes the deciding factor.
The symmetrical core is where the RG(radius of gyration) differential between the high and low axes differ by less than 5%.
So since this differential number is going to be less, then we can expect the Flare Potential to be less, or less hook at the break point.The Symmetrical Core is the same all the way around the ball at least on one axis say horizontal, but not vertical.
This should deliver a smoother line, with less angle, and a ball that starts to hook sooner, with a smoother arc to the pocket.This is important because it means the lower the RG differential, the less Asymmetrical or lower the hook rating on the ball will be. Or the more Symmetrical or smoother the ball and less flare in the hook motion.
Who Would Want a Symmetrical Core?
If you throw a slower speed ball or bowl on drier lanes then the Symmetrical Core will give you a smoother arc motion. Or maybe you find you ball hooking away from the spare shots you are trying to make, then the Symmetrical Core will tend to give you more control an help make those shots easier.
Asymmetrical vs Symmetrical cores should mean something to you now, if nothing else, you should have some idea what the two behave like on the lane.To put is simply:The Symmetrical Core allows a medium hook to occur, where as the Asymmetrical Core gives the ball a more sharp aggressive action.
The Choice is Yours
The biggest difference in the Asymmetrical vs The Symmetrical core is that Asymmetrical will deliver more aggressive movement, while the Symmetrical core will deliver a more consistent and smoother motion overall on any conditions.
But the key to know is that the core is not as important as the cover stock in terms of aggressive hooking balls. So, the less experienced bowler who doesn’t yet have enough knowledge about aggressive hooking balls would likely enjoy using a more controllable ball.
However, combine a strong cover stock to the Symmetrical Core and you can also produce a ball that hooks hard, but in a more predictable motion to the pocket. The Motive Forza is the Symmetrical Core pictured above
The drilling layout is also a very important factor in how a ball is going to behave, because you are changing how the weight is distributed in the the ball as rolls going down the lane.
So, technically we could alter cover stocks and drilling layouts and get nearly similar results from both cores, but the Symmetrical Core is much more limited.There are many more options with the Asymmetrical core, but the Asymmetrical core will expose or magnify a bad release.
The bottom line would be your preference on how a particular core, cover stock and drill layout delivers the motion you tend to feel most comfortable with.
If you were bowling on dry conditions almost constantly, then a combination of shiny pearl type finish with a Symmetrical Core would most likely deliver the most controllable and least hook motion.The more control you have, the easier it becomes to get the ball to the same spot over and over. Then the game becomes more enjoyable.
Any questions or comments,please leave it below
Check Out Some Different Cores Here: Bowling Balls