Go Back   HammerTalk > Equipment and Layouts

Thread Tools Display Modes
Old 07-28-2011, 01:39 AM
TenPinSniper TenPinSniper is offline
Senior Member
Join Date: Feb 2005
Posts: 5,812
Thumbs up Understanding the Effects of Surface Adjustments

The Ball Motion Study, completed by the United States Bowling Congress Equipment Specifications team in 2008 with cooperation from ball manufacturers proved that the coverstock of a bowling ball is the predominant factor in ball motion. This study showed that surface roughness and oil absorption were the 1st (Surface Roughness -Ra), 3rd (Surface Roughness RS), and 5th (Oil Absorption) most important variables in the 18 variables set by USBC researchers during the study. (See the full study here) While the actual specification set for Surface Roughness Ra effects only the manufacturers of bowling balls, bowlers can manipulate their bowling balls to change these values and accordingly change their ball motion.
Surface adjustments are imperative for a bowler bowling on multiple Sport Bowling conditions and tournaments , such as the USBC Open Championships. Most bowlers understand that the lower grit Abralon pad or sandpaper sheet you use, the stronger and earlier your ball motion becomes. Lets take a look at how much an Abralon pad really affects the surface roughness of the ball.

Figure 1: Average surface roughness Ra and 99% confidence interval error bars of bowling balls measured at various Abralon surfaces.
Figure 1 shows the average surface roughness Ra (Peak to Valley measurement) of a bowling ball tested at a variety of Abralon surfaces and then polished at each of those surfaces. The average Ra for a ball at 180 grit is over 100 microinches, while the average of a ball at 4000 grit is below 10 microinches, a drastic difference. The black lines in Figure 1 show a 99% confidence interval for each surface, which is 3 times plus or minus the standard deviation. (See table below)

180 grit

RA - Average


RA - Standard Deviation


3 times Standard Deviation
Upper Confidence Limit


Lower Confidence Limit


Figure 2: Explanation of 99% Confidence Limit

What the 99% confidence intervals demonstrate is that only 1% of the time will a bowling ball fall above or below the confidence limits. Aside from the statistical jargon, the important thing to see in the graph is the larger the black error bars, the more inconsistent the surface is at that preparation. Sanding a bowling ball with a 180 grit pad produces a Ra number anywhere between 70 and 135 microinches, based on the current data, while a 500 grit pad produces a Ra only between 30 and 50 microinches. The overall Ra number of a ball, especially at the lower surface finishes depends more on the chemical composition of the coverstock than a ball prepped at higher surface finishes.
Figure 1 agrees with the commonly known fact throughout the bowling industry that higher grit finishes on a bowling ball reduce the amount of overall ball motion (due to reduction in surface roughness). The important aspect from this is not that lower grit Abralon pads make a ball have stronger ball motion, but that the consistency greatly decreases as you lower the grit value. With a 2000 Abralon pad the entire surface of the bowling ball will be very similar, where at 180 grit you will have a wide range around the surface of the ball, resulting in the possibility of inconsistent ball reaction while bowling.
Speaking of reducing ball motion, one of the most common things heard in a pro shop if someone has a ball that "hooks too much" or "too early" is to polish the bowling ball using a USBC approved polish. Figure 1 above shows a typical polish used on a ball and applied at various surface preparations. Below you will find a similar graph, but showing the average and 99% confidence interval bars for RS, the surface roughness measurement from peak to peak. From the graph you can see that as you apply polishes to balls with lower and lower surface finishes, the inconsistency of the surface roughness after polish is applied increases dramatically. This can be seen as well in the Ra graph, but is more apparent in the RS graph shown below. (Note: Although the statistics may show it, it is not possible to have a negative surface roughness on a ball as shown in the 1000 + polish bar.)

Figure 4: 1: Average surface roughness RS and 99% confidence interval error bars of bowling balls measured at various Abralon surfaces
Inconsistent surface roughness can lead to inconsistent ball reaction, and with this it is not recommended to apply a polish product to a bowling ball surface prepped below 2000 Abralon.
What effect does polish have on ball motion?
Many bowlers have varying theories and ideas on why and when to use or not use polishes. Despite there differences, most high level bowlers felt that polished coverstocks create a more angular breakpoint. Former Team USA Bowler and current Sport Bowling Erik Vermilyea states that polishes " will give me the increased length, and also increased backend, but does tend to be less predictable and more squirty." USBCs Director of International Development and 6-time World Champion Bill Hoffman feels that polishes tend to make his equipment "super clean and flippy." USBC recently performed a test using the same ball at varying surfaces to validate this theory.
For the test the same ball was used at 4 different surfaces 2000 Abralon, 4000 Abralon, 2000 Abralon + a common polish, and 4000 Abralon + a common polish. 5 shots were thrown at each surface on a freshly oiled typical house condition, and the average was taken for each set of shots. Using the same methodology used during the ball motion study, the linear skid and roll phases will be separated from the hook phase. In the hook phase, quadratic regression will be fitted to the data for each surface modeling the equation ax2+bx+c. In this equation, the a coefficient defines the concavity of the quadratic the larger the number, the more concave or "angular" the path. Thus a larger a coefficient or A score will correlate to a bowling ball being more angular at the breakpoint.

Figure 4: Cats Data showing ball path for ball at various surfaces.
A Score




2000 + Polish


4000 + Polish


Figure 5: Table showing "a score" for each surface.
From the data we can clearly see that as the surface finish of the ball increases in grit, the 'A score' of the hook phase increases. This proves the theory that polishes will increase the angularity of a ball. Although at face value these numbers might not mean much to the average bowler, they show that between 2000 Abralon and 4000 Abralon with polish there is a 30% increase in angularity. This more concave or angular ball path however is often more difficult for a bowler to line up to the pocket. In order to maximize your arsenal potential, it is recommended to see a USBC certified coach or IBPSIA certified pro shop operator to assist you with ball selection and surface preparation for bowling on a particular lane surface and pattern.
Despite this data proving our hypothesis, it is important to realize that this one test additional testing is required to fully prove this theory. Look for a continuation of this study and more exciting ventures into the technical side of bowling including oil absorption, progress on the International Training and Research Center, "Harry II", and much more in the future.
Remember to Bowl with US!

Posted by Dave34
Oh and Idle, you're a left-handed stupidhead.

Posted by can-ham
I'm all for learning versatility that's why I have so many different balls...

Last edited by BubbaRay; 07-28-2011 at 06:41 AM.
Reply With Quote
Old 01-06-2012, 09:37 PM
TenPinSniper TenPinSniper is offline
Senior Member
Join Date: Feb 2005
Posts: 5,812

Think this is another good addition to the thread.


Originally Posted by BowlingChat, user: [B
Had a chance to use the Jayhawk surface scanner yesterday and was very surprised with the results. I scanned the following balls:

Storm Reign 3000 sia 15 games ago scanned 5300

Marvel 500/2000 Black Magic polish 6 games ago scanned 5263

Nano 500/1500 Black Magic 10 games ago scanned 4862

Taboo pearl burned with white pad scanned 4739

Frantic off the shelf scanned 5800

And a guy brought his Nano in after a 3 game set to see how much the surface had changed. Before bowling it scanned 1850. After just 3 games it scanned 4200!!! I was shocked. Quite interesting to say the least.

Just thought I'd share that for free.
Posted by Dave34
Oh and Idle, you're a left-handed stupidhead.

Posted by can-ham
I'm all for learning versatility that's why I have so many different balls...
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 03:28 PM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.