Coverstock – Part 5

How do Solid Reactives, Pearlized reactives, Urethane ball motions compare to each other?

Remember the Hockey Stick shape, well, the Reactive balls tend to resemble that more while Urethane exemplifies the Banana shape.

This is all about what we call “Skid, Hook, and Roll”, the phases a bowling ball goes through as it goes down the lane. These distinct phases were demonstrated in the USBC Ball Motion Study.

Hockey Stick vs Banana ?!?
In general, reactive resins are distinct from Urethane, and plastic for that matter. Why do we keep talking about the Hockey stick? Well, it might be a bit of an exaggeration, but compared to the smoothness of Urethane, the backend reaction of solids can look like that. Why is that? Well basically, the chemistry of the reactive resins make the ball react slowly to oil and quick to dry. In other words, reactive balls like to skid in oil and as soon as they hit dry boards, they make the big move (hook and roll). So imagine that on a 41ft THS, there is oil for 41 ft. There will be 19 feet to the head pin that is not oiled. So a reactive ball will tend to skid for much of the first 41 feet as it starts to transition to hook, it will hit the dry which will make the hook more pronounced and then go into the roll phase. It reacts so quickly that it really looks like it moves left hard (for righties). When a reactive ball is pearlized, it reacts even less to oil, but very quickly to dry. Since it is mostly skidding in the oil, it stores more energy for when it hits the dry. So the ball will turnover, i.e., hook and roll, very quickly.

Urethane works quite differently. Urethane reacts much more slowly to the dry but a little quicker to oil. So it will start to hook sooner than a reactive resin. And when it encounters dry, it does not make a big move. You would not be able to play the same line with a urethane ball as you do with a reactive one. Urethane is very smooth and thus why I reference the Banana shape ball motion.

Compare Skid, Hook, Roll
So in simple terms to aid understanding:
Reactive resin: Medium/long time skid, medium time hook, short time roll
Pearl Reactive: Long time skid, short time hook, short time roll
Urethane: Short time skid, medium time hook, medium time roll

Depending on different lane conditions, you can alter the surfaces of these coverstocks to allter the Skid, hook, and roll times.
Take a 2000 grit reactive:
For example, if the lane is very oily, this may increase the skid time. By doing this, there will be less time for hook and roll. The ball may not be effective. So you can bring the ball down to 1000 grit. This may help the ball shorten the skid time by increasing the surface roughness.
Another example would be if the lane was dry causing the skid time to be very short. That may will generally increase the roll time, meaning the ball has gone through it’s transition between the three stages and is now rolling end over end for a longer time. This is what’s called rolling out. You can bring the ball up to 4000 grit to lengthen the skid time. You could polish the ball and stay at 2000 grit. This will also lengthen the skid time. You could switch to a pearlized ball to lengthen the skid and change the entry angle. You could switch to a Urethane ball which will alter all phases. Can you make those decisions when it counts??

This is where picking the right ball, the right surface, playing the right part of the lane, really come into play. This can be quite complicated so if it sounds overwhelming, I won’t kid you and say it’s not.

I wanted to bring this topic to the forefront because it is crucial. If you are a beginner, these are quite complicated decisions so you have much more to gain by solidifying your physical game first. However, for the true par or experienced bowler, making these decisions will be the difference in scoring 250 and 200.

6 thoughts on “Coverstock – Part 5”

  1. This five part series is excellent. As a beginner this cleared up many things I have read about but not truly understood. Many thanks.

  2. I’m glad it was helpful. There are a lot of things “long-time” bowlers take for granted, and some things are are truly misunderstood. Nevertheless, I hope to share information for all to learn about our great sport!

    1. Hi. Thanks for noticing that. For some reason it was only appearing in the General section. I’ve fixed it so it appears in the Coaching section.
      Happy Reading!

  3. Great articles!!! Thank you!

    I think I spotted a typo unless I’m confused about what is being said. In the “Coverstock Part 5” article under “Hockey Stick vs. Banana?!?”, it states,

    “In other words, reactive balls like to skid in oil and as soon as they hit oil, they make the big move (hook and roll).”

    Shouldn’t this say,

    “In other words, reactive balls like to skid in oil and as soon as they hit DRY, they make the big move (hook and roll).” ?

    Thank you for these excellent articles. I’m a beginning bowler and find your articles concisely explain complex concepts in a way that really helps me understand them. Great job Coach!

    Best regards,

    1. Hi Jim. Thanks for noticing that. You are correct, I’ll fix it. Glad you are enjoying the articles.
      Good Luck!

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