I have recently been asked this question. I wrote this article back in 2004 regarding this topic. Please let me know if you have any other questions in the comments below.
Recently, I was in a discussion about bowling balls and the topic of ball size came up. Not knowing if size really mattered, I decided to set up a test to hopefully provide some insight into the very heated topic. So, in this issue of Tech Tips, we will explore bowling ball size from a subjective standpoint.
For years, professional bowlers and amateurs alike have said smaller balls hook more, or can go deeper into the pocket, and as a result, will carry better. There has been an equal amount of talk about larger balls. Bowlers have said that larger balls hit better or that larger balls make the pins fly more. So, wondering myself how size effects ball reaction and pin fall, I decided to set up a small experiment to try to find out if size matters or not. The ABC/WIBC specification for diameter is 8.595" to 8.500". Knowing this, we set this test up to sample a range of the specification.
The Set Up
For this experiment we chose three different styles of players. Each player was given the same ball at different sizes.
The sizes were:
1. ABC/WIBC Maximum Diameter 8.595"
2. Ebonite Standard Diameter 8.585"
3. Test One Smaller Diameter 8.550"
4. Test Two Smaller Diameter 8.510"
One of the first things that we decided to look at was inertia or ball dynamic properties of balls. We tested each ball for Rg and differential.
The following is an average list of all of the Mass Properties for the balls:
We also weighed each ball to find out how much difference existed between the balls:
It is interesting to note that size does play a role in Rg as well as differential. Notice that the larger the size, the higher the Rg value and the lower the differential value. These changes are a result of the smaller coverstock allowing the core to play a greater role in the dynamics of the ball. Also, the balls differed as much as 0.36 lb between the highest and the lowest weighted ball.
The ball that was used in this test was the Ebonite V2 Clean. The players were instructed to bowl a minimum of 30 games with each ball in a variety of conditions and houses, and then to comment on each ball as well as select a favorite ball.
Player 1. Professional Bowler and Ebonite Pro Staff
Name: Jason Queen
Rev Rate: Low
Ball Speed: Slow
Style of lane play: in the track
Favorite ball size: 8.510”
I tested all of the balls on PBA pattern B and pattern E as well as a house condition. The balls were also thrown on two different lane surfaces, Brunswick Lane Shield as well as Brunswick Pro Anvil lane. The reaction differences were the same for all lane conditions and lane surfaces comparing the balls to each other. The smaller the ball, the lower the pins flew. The smaller the ball, the better the ball cut through the pins. The 8.510" ball carried the best by far. At one point I threw 28 strikes in a row with it. I was amazed at how much entry angle I got from the 8.510" ball. The ball felt the best in my hand, like a softball. I could tell a big difference in the feel of each ball. I felt like I could really rev it up if needed. The ball motion of the 8.510" ball was long and very angular compared to the other balls. The larger the ball, the more even rolling and smoother the ball reaction. I had a tough time carrying and left a lot of 10 pins with the 8.595" ball. The bigger the ball, the quicker the ball stood up in the midlane. I felt that the 8.510” ball was five to six boards stronger than the 8.595" ball. The 8.510" ball will definitely stay in my competition bag!
Player 2. Mega Buck Amateur Bowler
Ball Speed: Medium
Style of lane play: inside out
Favorite ball size: 8.510"
I threw the balls on wood and synthetic. I also used the balls on a Sport pattern, a short
house pattern and a long house pattern. The differences in the balls remained the same on
each condition and surface. I like the feel of the 8.550" ball the best.
The 8.550" ball hit harder than the 8.585" ball but less than the 8.510" ball.
The 8.510" ball carried the best and hit the hardest. The 8.595" ball seemed to be hard to rev. It was very hard to kick out the corner pin. This ball on impact made the pins fly higher. The differences in span seemed enormous, but when the balls were checked for span, they all measured the same. I think that the smaller the ball, the more angular the ball is and better the carry is in general. Light hits seemed to carry better with the 8.585" ball.
The 8.585" ball was good, but if I had my choice I prefer the 8.510" ball because it struck the most.
Player 3. High Average League Bowler
Name: Ron Sr.
Rev Rate: Medium
Ball Speed: Medium
Style of lane play: outside
Favorite ball size: 8.510"
I tested the balls on a Guardian surface in one house and on a wood surface in another house. There was a difference in ball reaction from the two houses. In the house that had Guardian, I did not see a big difference in all four of the balls. I really liked how the smaller ball carried the pins and rolled off my hand. It had a very angular entry into the pocket, which was very predictable. I like the feel of the smaller ball. It really feels good in my hand. The ball with the 8.585" diameter felt noticably different in my hand, and the carry
was not as predictable as the smaller ball.
The ball with the 8.595" diameter felt stretched in my hand and was hard to rev up. It didn’t seem to be as smooth or controllable as the 8.585" ball. On the wood condition, this ball moved a lot earlier than the 8.585" ball and it seemed to lose its hitting power when it got to the pocket. The 8.510" ball rolled the same as the 8.595" did in the Guardian house. It was very controllable and hit the pocket very well with great carry. The 8.550" ball hit harder than the 8.585" ball, but it didn’t carry as well as the 8.510" ball. If I had my choice of the balls, I would be in favor of the 8.510" ball because of how controlling it was and the hitting power it displayed when I threw it.
We decided to test our balls as well as competitors’ balls for size. We purchased competitive balls on a random basis from several distributors. Our balls averaged 8.585". The competitor balls that we tested ranged from 8.545" to an illegal 8.607".
Ebonite currently uses the 8.585" specification on all bowling balls to allow for maximum
resurfacing of its products. The following chart is an average of two balls.
There were some interesting results about size noted by all participants. Everyone noticed a significant difference in the feel of the balls. The radius of each ball was different based on the size and each player noticed this difference even though the balls have the same span measurements. The smaller ball felt like it was drilled shorter than the larger ball. The legal limit on ball size is also very noticeable when using a quarter scale (see pictures 1 and 2). Even though both of these balls are within ABC/WIBC specifications, there is a gap in size. Everyone also agreed that there was some difference between the balls.
Currently other manufacturer’s product diameters are different and vary from ball to ball. The ABC/WIBC specification for ball diameter is large enough to see differences by players of different types, styles and abilities. Even though not completely conclusive from our small test, it can be said that from a player standpoint that the size of a bowling ball does play a role in ball preference and performance. In this preliminary test, all players
seemed to prefer the 8.510" ball over the other sizes. A variety of reasons can be attributed to this, from the way the ball feels in a player’s hand, the increase in rev rate from a smaller ball or because the smaller ball was lighter and offers more control for a bowler. We will continue to test these different size balls, only now on a more formalized basis. We will also begin to collect C.A.T.S. data as well as use Ebonite BowlersMAP™ to help conclude an opinion on our early findings. Who knows? Maybe, as a result of this experiment, we might end up reducing our manufacturing ball specification. We won’t know for sure until we have more facts. For now, at least, it appears that bowling ball size does matter.
A number of years ago I bowled in a non-sanctioned league. One of the bowlers had his ball badly damaged by the equipment and the management “repaired” it by sanding off enough surface to remove the chips. As a result, the ball was much smaller. The owner claimed that it had never performed as well as it did now. It was now an illegal ball for USBC competition because the manufacturer’s logo was gone!
I then read your test of ball size and thought about the possible explanation for the effect. A ball of 8.5 inch diameter would hit a pin just below the pin’s maximum diameter, imparting a slight upward force vector while a larger ball would hit just above the maximum diameter, imparting a slight downward force.
Upward force would lift the pin and free it from friction with the pin deck, reducing the energy needed for pin motion (it is airborne). A larger ball would lose more energy and also be lifted slightly at impact. Could this be the answer?
A video by the manufacturer of the Haus machine claims that the professional bowlers have new balls made smaller because they carry better.
USBC claims that after manufacture, a ball’s diameter can be reduced to any size, provided the manufacturer’s logo is still there; only serial numbers can be re-engraved.
I took a Motive ball that I had 400 game scores recorded on and had my pro shop reduce the diameter to 8.5 inches. Since Motiv casts their logos into the ball, it is still “legal” per USBC (I will have the serial number engraved when my tests are complete). So far the ball is averaging higher scores by 10-15 pins per game but it is early days.