The first topic we will cover is the effect of ball weight on rev rate. Recently, many (if not most) bowlers have switched to 15 pound equipment. Many of the touted benefits are decreased fatigue, increased revolutions, and for some, increased deflection. It is hard to argue about the fatigue factor – even using a free arm swing, there are points in a swing where the weight of the ball is supported by the body, and a lower weight ball will lessen the strain. But, just how much can the change in ball weight affect the bowler’s rev rate?

The Setup

• The bowler will put the same amount of energy into his release with each ball. With a heavier ball, it is possible that the bowler would eventually fatigue, causing him to put less energy into the release, but we aren’t going to take that into consideration this time around. We will assume that the bowler has trained sufficiently for the amount of bowling they will perform, so fatigue will not be a factor.
• We will examine 3 ball scenarios – a low RG core and a high RG core, whose RGs change as weight changes, and a medium RG core whose RG is constant. MoRich changes the density of the core in their different weight balls, so that the core dynamics are the same for all weights.
• We will look at the effect of dropping from 16 lbs to 15, 15 lbs to 14, and 16 lbs to 14.
• When calculating rpm differences, we’ll use a bowler with a rev rate of 250 rpm with a 16 lb ball, no matter which ball that is. A bowler that put 250 rpms on one ball would not necessarily put 250 rpms on another ball of the same weight, but with a different RG.

The Science

The technical specs for the balls we will be analyzing are as follows:

Now, we need our formulas. There are 2 formulas that we will need to look at. The first relates the rotational energy of an object to its angular momentum (rev rate) and Moment of Inertia (MoI). The second equation gives us the MoI for the ball. The MoI is where the ball’s weight and RG come into play. What is RG in scientific terms? The value is an expression of an object’s resistance to change in angular velocity. A bowling ball’s RG represents the radius (in inches) of a hollow cylinder that would have the same MoI as the ball. So, a higher RG equates to a larger cylinder. The formulas are:

and

Where:

• KE = The kinetic energy of the ball
• I = The moment of inertia of the ball
• M = The mass of the ball
• R = The RG of the ball
• ω = The angular momentum of the ball

Next, we combine the 2 equations:

Since we are assuming that the bowler will apply the same amount of energy into rotating the ball, we know that the KE side of the equation will be the same for both balls. So, we have the following equation, where the variables with a subscript of 1 are the values of the first ball, and the variables with a subscript 2 are the values of the second ball. Let’s start with the first case, the 16lb NVD vs. the 15lb NVD. We will fill in the mass and RG, leaving the angular velocity to be calculated:

This means that the 15 lb ball will see about a 4.1% increase in revs, over the 16 lb ball. Substituting 250rpm at 16 lbs, we see that the 15 lb ball will have around 260 rpms.

Calculating the rest of the values in the same manner, we see:

Conclusion

What can we take away from this? One thing that stands out is that the difference is not very significant – dropping from 16 to 15 gave, at most, a 4% gain, which is not a great deal. Another thing that stands out is that if the RG of the ball goes up as the weight goes down, the gain is much smaller. When the RG dropped, the gain in rev rate was magnified. Analyzing the equations, we can see that when the RG remains constant, the percentage difference in rev rate will be the percentage difference in the square root of the weight of the ball. If the core changes in dynamics, that difference can be exaggerated or reduced. My conclusion? A higher rev rate is not a great reason to drop in weight.

References

The following were used as sources/inspiration:

http://hyperphysics.phy-astr.gsu.edu/Hbase/rke.html
http://www.bowlingcommunity.com/b/ubbthreads.php/topics/72012/Re_Best_ball_for_pin_axis_dril.html#Post72012

This year, Norm and Bob returned, and we got Brian Voss as well. In addition, former touring pro and national title holder Mike Shady came down from Erie to do some video work as well. I really liked his coaching style, and will most likely be contacting him for future lessons.

The basic structure of the event was a short classroom period, where they discussed the modern stance, pushaway, and timing of each of the last 4 steps. After that, we split into groups. Those that had attended the one last year were sent to one side of the house with Norm to go over some drills quickly, the others stayed on the other side to go through them a little more in depth.

The Drills

The only drill we did was a 1 step drill. When I did this last year, I was having a real hard time with it – I kept falling off balance, and I just couldn’t get it. This year, I did much better. At first, because of the way I hold my ball, Norm didn’t think that I was holding it in my left hand, but I pulled my right hand out of it to prove it to him. He got the ball more in line with my shoulder, and that was about it. I was very balanced, very free with the armswing, and had a nice medium release going with the 1 step. Once he got everyone through that drill, he had each person bowl 1 ball while everyone watched. Then he would critique for everyone to hear, so that everyone could learn from the mistakes, and then move on. When it came time for my shot, he just said “That’s awesome” and moved on.

Lunch

By the time we got to the end, lunch was ready, so we all stopped for a bite. While this was going on, they stripped the lanes of the house shot and laid down 3 patterns in 3 parts of the house – the Viper where we were, the Shark, and the Cheetah. During lunch, I caught up with Norm Duke and asked him if he could go over something that he had done last time. He was talking about how he visualizes the lanes when he is building his target line and his approach, but I had not had a chance to write down what he said, and I missed/forgot some of it. He didn’t have time to go into it completely, but he did address it generally for everyone while we were waiting for the lanes to be oiled. Here is what he talked about this time around:

While some bowlers walk in a line parallel to their target to keep their swing on path, and when they get far enough left have to do 3 steps in front of the ball return, Duke (and some others) use a figure 8 swing to change their ball path. To do this, he pictures a “Y” on the lanes. For this example, we’ll say his target line is over 15, out to a breakpoint at 10. To build the “Y”, draw one line from the foul line, through 15, out to 10 at the breakpoint. The other line is drawn from the arrows at 15 out to 20 at the same distance as the breakpoint. It is towards that point that Norm pushes the ball in his pushaway. Then, the ball swings from inside to out, loops around (because his swing is free), and puts the swing at the correct angle to play out over 15 to 10.

The question that didn’t get answered is “Where do you line up your feet?”

The Viper

After this, we went back to our side, which had the Viper, and Brian Voss came over with us. It took him a while to make it down to our side. In the meantime, I found that my best line was using my Total Inferno with my regular release and medium speed over a target of 11-12 at the arrows, out to 7-8 at the breakpoint. While he was on the other end of our section, Bob Learn came over with the proprietor, and put tape on our pair from the foul line out to the arrows. One strip was up the 3rd board, and one was up the 12th. They want us in the area, so… there went my line! I tried to force myself into that area, and then just moved over a pair. Voss was there, and took a look at one shot. He had nothing bad to say, and was moving on, so I asked if he could watch a couple more shots where I tried to play different parts of the lane. First, I moved way left, trying a target inside 3rd arrow. I turned the ball early – he didn’t really comment on that one. Then, I tried moving left, playing a straighter shot. I went for the “Ring Finger” release from my earlier article on axis rotation. The line I tried was straight up 8, and it didn’t make it back up to the pocket. He liked that one, but I still had my hand in a strong position on that shot. That is, my fingers were on the inside of the ball until the release point. He had me try another one to cut down my rotation even more, starting my hand on the outside of the ball at about 15 degrees and just holding it there. I moved further right, but ended up pointing the ball a bit, and it crossed over. I actually liked the reaction I got out of it though, and will be experimenting with that release for my upcoming sport league this summer. Once we were through, I moved over to the other side of the house to take a shot at the Shark.

The Shark

It was playing pretty tight. Some lanes were broken down a bit, and I was able to play the Big One between 3rd and 4th arrow out to 11 or 12, with great success. The ones that weren’t broken down nicely required the Infinite One straight up 10. Bob Learn was over here – he watched one shot and said “Great Shot”. I think they left the house shot on the pairs that were being used for video, because on those ones, I was really wheeling the Big One. The line for video was pretty backed up, so I went over to the other side of the house to see how the Cheetah looked.

The Cheetah

It may have been playing near the gutter when it was first put down, but the shot was shot by the time I got there. If the ball got outside of 5 it never came back. I only played a couple shots here before they announced that Norm had to leave early (probably going to the Roll to Riches event). So, I went to get his autograph and say thanks. Bob and Brian started signing then as well, so I hit them up and thanked them for their time and advice. Finally, the video area was open! Mike Shady, here I come.

Video

As I said, these were taken on the house shot, which was nice and toasty by this time. I was playing pretty deep, starting with my feet around 40 and playing 4th arrow or just left of it, letting the ball out to about 9. I took a shot for the camera, and we watched it in slow motion. He liked my timing a lot – good pushaway, good free swing, ball slightly late at the line. Then he asked me what I had been working on. I told him the pros all really liked what they saw – I had been working with Voss on adjusting rotation for playing different lines, and that Norm had mentioned the laziness in my balance arm. Mike agreed with those things, and went a little more in depth on the balance arm. He said that once I get it out on my pushaway, I can leave it extended in front of me to help open my shoulders when I’m opening up the lane. If I am trying to play straighter, I can keep that arm more to the side, which will square up my shoulders. So, that’s something to play with in practice. He was using Ebonite’s Digitrax software, so we checked a couple of things on that before we finished up. The first thing he checked was spine angle – I started out around 35, and slowly stood up through out my approach till I was at about 27 degrees at the finish. He’d like me to be closer to 27 the whole time, or move from a starting position at 26 to finishing around 28. However, I was starting with more angle than normal from the way we had been changing the setup, so that should be an easy fix. Next, he timed the acceleration of my downswing, and we found that I accelerated at the right point (about 6 inches before my ankle), which was cool – I thought I pulled the ball down more than that. I think when I get inside and need to turn it a bit more, I run into problems with accelerating it early, so now I have that knowledge if I feel it happening.

So, in summary, here are the things that I think I really need to take away from this day.

Stance

• Get both of my elbows tucked into my body, with the ball directly in front of my right shoulder.
• Make sure the weight of the ball is in my left hand. I get lazy with this sometime. I might experiment with opening up my left hand to hold the weight. Right now, I use a technique that Ron Clifton has shown in this article, where I make a sort of V with my thumb and forefinger.

Pushaway

• MOST IMPORTANT: Get that pushaway going straight to my target. When I do it right, it feels like I’m pushing it a little to the left. I have a tendency to pull the ball, and I just know it starts here. Once I knew to look for this as a culprit, I could feel it every time it happened, and I pulled the shot every time.
• Make sure I get a nice hinge motion with my pushaway to keep my timing/balance in tact. I have a tendency to push out and lock sometimes. Chris Barnes has a nice pushaway to think about for this one.
• Norm noticed that after my pushaway, I drop my left arm. I need to work on keeping it extended after the ball drops into the swing. As I was working with Mike Shady, he talked about using it as a tool – leave it in front of me to help keep my shoulders open, or point it at the left wall to square them up to the line.

Approach

• Nothing from the pros here, so I want to start experimenting with taking a step to the left, or a step to the right, and seeing what difference it makes in my ball path.

Release

• As Brian Voss said, and as I’ve been planning to do, I need to work on tweaking my axis rotation for playing different lines. I need to work on killing some hook while still retaining a powerful shot. When I am turning it more, I need to work on not turning it early.

Finish

• Norm wants my trail leg to be a little further back at the finish, so there is more distance between my knees. This will lead to more stability.
• I need to make sure I stay down and post my shot. I was doing it the whole time I was there, but when I get into other situations (tournaments, league) I get lazy with this sometimes.

While the most versatile pros can change their axis rotation to virtually any angle between 0 and 90 degrees, we are going to work on learning 4 different release keys that will give us a pretty broad range of axis rotations to work with. What we are going to do to change our axis rotation is concentrate on driving towards the target with a certain finger. To give this the best chance to work, follow-through has to be long and low. You will need to reach out to the target, letting the ball roll off your hand. In addition to driving with a specific finger at the release point, I will provide different finger positions that can be used in the setup, which will help tweak some of these releases further.

No Rotation (0-5°)

To kill the axis rotation on your shot, you will want to use your pinkie finger to drive towards the target. The corresponding starting finger position for this type of shot is to have the pinkie finger spread out from the ring finger a bit, and have the index finger in a bit closer to the middle finger. Pulling the index finger all the way in may result in some instability at the release point, so experiment with this and find what makes you comfortable. This release is best for shooting straight at spares.

Minimal Rotation (15-30°)

To achieve a minimal amount of axis rotation, concentrate on driving to your target with the ring finger. This will lead to more of an end-over-end roll. A good finger position for this release is to have both the index and pinkie fingers pulled in. You don’t need to have them touching the ring and middle fingers, but getting them in close will help your hand get to the right position in the release. This is the type of roll that Walter Ray Williams Jr. and Norm Duke are famous for using on TV, and is usually a good starting point on flatter patterns.

Moderate Rotation (~45°)

This release is a pretty good starting point on a typical house shot. The driving finger for this one is the middle finger. The finger position that matches best with this release is to have the pinkie in near the ring finger, with the index finger spread out a bit from the middle finger. You may also find you like to keep both the index and pinkie fingers spread out a bit. Try both, and note the difference in feel and reaction.

Maximum Rotation (up to 90°)

This release has the maximum amount of side rotation. Think Pete Weber. For this release, you want to concentrate on driving through your target with your index finger. It will help to spread your index finger out as far as possible from your middle finger. You should also get your pinkie in tight against your ring finger. You may wish to try tucking your pinkie finger as well. Some people will find this very easy, and some will find it difficult or impossible to do pain free. If tucking your pinkie hurts, don’t do it.

A note of caution with this release. It is common to try too hard to get your hand around the side of the ball when performing this release, which can cause several bad habits – turning the hand early, grabbing and lofting the ball, or hitting up on it. It is essential that you stay behind the ball until the release point. It may take several rounds of practice before your wrist is trained to get a high amount of axis rotation while still using proper technique. Don’t worry, and don’t rush it. This release, while being very impressive (Look at all that hook!), is the hardest to control, and it will very rarely be the best way to play the lanes. To get the maximum benefit for your game, it is best to master the first 3 release techniques first, then come back to this one once you are comfortable with the others.

Ok, Great! Now When Do I Use Them?

The No Rotation release is good for shooting straight at spares. It might also come in handy if you find yourself in a position where you have to point the ball at the pocket, but even then, the Minimal Rotation release might be better suited that type of shot.

The Minimal Rotation release is a great starting release on tighter/sport conditions. This release will give you a much more even response at the breakpoint. It is also good on a house shot when you are experiencing an over/under reaction with a higher axis rotation release. Finally, on heavier oil, this release will promote an earlier read of the lane, which is generally what is needed, at least until the pattern starts to breakdown.

The Moderate Rotation release is often times a good starting point on a house shot. Usually, with these types of shots, you will start out playing a moderate angle, and you will need a bit more rotation to make it back to the pocket from the breakpoint. Also, when you start moving in from an outside line with a lower axis rotation release, you may need to start increasing your axis rotation to get the ball to turn the corner.

As you find yourself moving farther and farther inside, you may need to move to a Maximum Rotation release. This release will provide you with the most skid downlane, but it will also react most violently to dry boards.

Where Do We Go From Here?

Well, one way to fine-tune these adjustments is to mix the driving fingers with different finger positions. For instance, if you are using the Minimal Rotation release, but the ball is coming in a little too flat, you might try spreading your index finger away from the middle finger. This will result in just a little more axis rotation, and it might be all you need to kick out the 10. Likewise, if you are using the Moderate Rotation release, and the ball is reacting a little too sharply at the breakpoint, you might try bringing your index finger in a bit closer to your middle finger, or spreading your pinkie a bit. This will keep you behind the ball just a little bit more, and can even out your reaction a bit.

Starting with the 4 ways we can drive our fingers towards our target, and then adding the different finger positions, we can fine tune our release to get just about any amount of axis rotation that we might want.

Video!

Here is the newer video. I’m leaving the old video below, but this is much better. Medium-Light oil, but not too dry outside. Wood lanes. Using an AMF VP2, a particle pearl with a medium RG and lower differential. I have my PAP marked so you can more easily see the angle of rotation.

Minimal Rotation

Left foot 19, 11 at the arrows.

Moderate Rotation

Left foot 27, 13 at the arrows.

Maximum Rotation

Left foot 37, 17 at the arrows.

Comparison Shot

These next shots were taken on what I would call medium-heavy oil, on wood lanes. Ball is a Total Inferno, lower rg and medium-high differential.

No Rotation

For this shot, I stood with my left foot on 10, and crossed 8 at the arrows.

Minimal Rotation

For this shot, I stood with my left foot on 15, and crossed 8 at the arrows.

Moderate Rotation

For this shot, I stood with my left foot on 20, and crossed 10 at the arrows.

Maximum Rotation

For this shot, I stood with my left foot on 23, and crossed 11 at the arrows. Note that this example did not get all the way to 90 degrees. Rest assured, the next video will.

Credits/Further Reading:

The 4-Point Release System, Joe Slowinski, Bowling This Month, November 2006
The Adjustment Toolbox (Part 1), Ron Clifton, Bowling This Month, November 2006

The back issue of BTM is available here. Ron Clifton’s article is also published on his personal web page here.

As a pre-requisite for this adjustment (and also for getting to the next level in your game), your arm swing must be free. When gravity is controlling your swing, adjusting speed is a piece of cake. When you are controlling your swing, you will be hard pressed to keep a consistent ball speed to begin with, much less be able to alter your ball speed with any repeatability.

Ok, with that said, how do we change our speed? Throw harder! Just kidding. The answer lies in the setup.

Everyone has a comfortable starting height for their ball. That may be chest height, waist height, down by your legs, or anywhere in between. I would suggest that, to get “medium” ball speed, the ball should start in the stance around belly-button height – perhaps a bit higher. This allows for adjustment either way, depending on what the lanes are giving you. Think about it this way – if you start with the ball below your waist, where will you go when you need to slow it down? Your only option will be to control the armswing, and that is never what we want to do. Likewise if your default starting position is with the ball up by your shoulder. When you need more speed, what do you do? You can only muscle the ball.

So, we’ll say that the ball in line with the belly button is our medium If we need to slow the ball down a bit, say, to get a little more hook downlane, we can simply lower the ball in our stance. This will also shorten the length of our swing, so we will need to move up a bit on the approach. I have found that a good number is about 1 inch on the approach per 1 inch of height. If you move the ball down 6 inches, move up 6 inches on the approach. This will cause you to subconsciously take shorter, slightly faster steps, and your timing should stay in tact. If you need to speed the ball up a bit, raise the ball from your starting position, close to chest level. If you move the ball up 6 inches, move back 6 inches on the approach.

There is not much else to say about this adjustment except that, to get comfortable with the different speeds, you will definitely need to practice. The feeling of the ball coming off your hand is quite different when you change speeds by a couple MPH, and you will want to be very comfortable with the different feeling before you try to execute it in competition.

Video coming soon…

Pittsburgh, PA: You are certainly one of the most versatile bowls on tour, with many adjustments at your disposal, as we saw in your recent title match against Ken Simard. Once a player has mastered their “A” game, what would you say is the first adjustment a bowler should learn to make, other than moving their feet, that will help them the most across different situations. Speed? Axis Rotation? Something else? Thanks.
Chris Barnes: You have hit on the main two that will increase your ability to hit most of the shots you see. The only thing to add to that would be adjusting your hand pressures.

---

Pittsburgh, PA: Sorry for all the technical questions – you’ve mentioned hand pressure twice. Can you clarify? Do you mean the finger pressure – how much you try to get on the ball? I have been working on decreasing this myself – trying to let the ball do the work, and eliminate the over/under I see sometimes. Are there situations where you find yourself trying to put a little extra on it?
Chris Barnes: Yes, that’s why you vary it. More to make the ball hook sooner and less to push it down the lane.

So when are these adjustments useful, and how do we make them? The next 3 posts will address these adjustments individually – tips for how to make the adjustment, and the resulting change on your shot.

Update: The first two tips are up, in rough form:

• Adjusting Speed
• Adjusting Axis Rotation

I went to Mars Lanes today for some practice. Having been on the driest lanes I think I’ve ever seen yesterday, I was really looking forward to having my ball stay on the right side of the headpin. Seems that they had a little more oil down than they have lately today – in fact, it’s back to the way it was when I first started going. Miss outside, and the ball just keeps sliding and sliding. Miss inside, and there’s no hold. It’s a good flat shot that tests your execution, and your release. You need leverage to turn the corner on this one.

First game I threw a couple warmup shots, one of which left a 2-4-10, so I decided work on those the rest of the game. I tried a new finger position – index finger in (but not quite touching the middle), pinkie out (but not stretching as far as possible). It worked well – gave me a much more consistent end-over-end roll. I found that I can line up 9 boards left of a pin to hit it dead on throwing up the boards (so standing on 34 to make the 2 pin – also good for washouts). I also found that moving 3 right on that will be good for shooting splits (standing 31, shooting 5th arrow, was good for picking up the 2-4-10). Note that when I list my starting board, I have a piece of tape on my left shoe right around my big toe area that I use to line up.

The next 2 games I shot for score, working on staying behind the ball as long as possible, and playing a couple different angles. My Total Inferno gave the best look – I had a line playing over 3rd arrow out to about 9 at the breakpoint, and also playing over 8 out to about 5. I ended up being pretty happy with my results, and the lanes made it abundantly clear when I threw good shots and when I threw bad. It was nice to get the feedback that is typically missing from a house shot.

On the video front, I did take my webcam and shoot some, but the results were not very good. I’m still working out the best settings for taking advantage of its high frame rate. Unfortunately, the image clarity isn’t the best – with the manual focus, you can only set one focal length, and even that is blurry. Once I get it figured out, I’ll post some nice high-res, high fps release shots. Until then, the regular old camera shots will have to do.