DEGREES OF SEPARATION: Being Able To Adjust Your Axis Rotation Is A Tool Worth Having
There are a few major indicators of how the ball will roll once it has left your hand: speed, rev rate, axis rotation and axis tilt. I believe a player’s ability to adjust their axis rotation has the greatest impact on their versatility. It’s one of the most valuable tools you can have in your bowling toolbox, and it’s quite common at the elite level. But it’s also something that is being taught more at the intermediate level as well.
Axis rotation is measured on the ball’s horizontal plane. We locate a player’s positive axis point (PAP), which is the stable axis upon which the ball begins to initially rotate. To better understand axis rotation, put a small piece of white tape on your ball’s PAP. If your hand is up the back of the ball at release, that piece of white tape will be on the west side of the ball (for right handers). The more your hand moves around the ball at release (or, the more axis rotation you’re able to create), the more that white tape will move eastbound. Adjusting the axis rotation will get the ball to react differently to the lane.
Generally speaking, balls skid, then hook, then roll. Less rotation will shorten the skid phase and get the ball into the hook phase earlier, while maximum rotation will extend the skid phase of the ball and increase its hook potential down lane. It’s such a valuable tool because it will change the ball’s reaction while still allowing you to stay in the same part of the lane and use the same break point.
Ideally, you would like to limit lateral moves on the lane because it forces you to make multiple adjustments. And often times, particularly on challenging conditions, the zone you’re going to have to play and the break point are pretty defined. This tool will allow you to stay in that area.
In theory, the range on axis rotation runs from 0 to 90 degrees. The closer you are to 0 (meaning your hand is almost directly behind the ball), the more end-over-end the ball will roll in a forward direction. The more “around” the ball your hand is at release, the more the ball will skid before hooking and getting into its roll.
The players with the capability of executing the widest range of axis rotation are considered the most versatile. Establishing and applying that versatility isn’t as daunting as it might sound. First you need to gauge your PAP. Again, do that by placing a piece of white tape on your PAP. You’ll probably need a spotter behind you (a teammate, coach or pro shop owner are possibilities). As you try different hand positions the spotter can tell you whether your PAP has moved from west to east, or vice versa.
You should also preset your hand position in your stance, more on the side of the ball or directly underneath it. And remember, your preset hand position is what you have to have at the release point. Players will sometimes start with their hand under the ball, but will gravitate back to their normal hand position by the time they release the ball. Your spotter will be able to tell you whether you’ve maintained the desired hand position through the release.
You may also notice some physical differences. When you deliver the ball with your hand up the back, you’ll feel more of the pads of your fingers come out of the ball. As you get around the side of the ball, you’ll feel the release more on the sides of your fingers. This method won’t give you the precise range of rotation you have, but it will give you an idea of the variance in reaction your axis rotation alterations can generate.
What you will notice is the change in your ball’s roll, not only by the way the ball travels down the lane, but by its reaction as well. Again, up the back will produce more of an end-over-end roll, with the ball spinning and traveling in the same direction. If you’re on the side of the ball, it will be traveling northbound, but appears to be spinning east to west.
How would a league bowler recognize the need to change his axis rotation? If you see that the ball is getting into its hook phase too soon, you may want to change your rotation. If the ball is hooking too early, getting on the side of it will produce more length. If it’s skidding too much, getting up the back of the ball will get it into the hook phase much sooner and give you a noticeably earlier roll and a much smoother backend reaction.
Certainly there are other ways to change your ball reaction. You can change equipment. You can change speed. But bowlers who can change their axis rotation see the most bang for their buck. If you have only one release and five balls, that’s what you’re limited to. But if you have multiple releases and multiple balls, your options are endless.
That’s why other factors matter, but being able to adjust axis rotation is such a potent tool to have.
— Kim Terrell-Kearney is Assistant Head Coach of Team USA and the International Training and Research Center in Arlington, Texas.