Skid, hook and roll: the phases of ball rotation
The rolling of a bowling ball down the lanes is a beautiful sight, but it is easy to see it as a movement rather than the various stages that make up the path of your ball.
As it turns out, ball rotation has three phases that are important to understand. This article goes into the basics.
The slide phase
This is the first phase of your ball's movement, occurring on the first 15 to 20 feet of the field.
In this phase the ball moves the fastest and also has the most axis rotation.
The hook phase
If it gets past the arrows at 20 or 22 feet, your ball will enter the second phase of ball movement called the hook phase.
This stage goes back to about 40-45 feet or so. This is also where the ball stopping point is located.
The roll phase
The final phase of ball movement occurs when your ball finally approaches the pegs.
At this stage the ball moves end to end without rotating its axis. It also runs at the slowest speed of all three phases.
Why ball movement phases are important
You may be wondering what to do with this information. Why are these three phases important to know as a bowler?
As it turns out, understanding the movement of the ball is critical to understanding the equipment: for example, what ball materials to use so that you can best suit the relevant lane conditions.
And understanding ball movement can help troubleshoot problems with both your equipment and technique that are causing sub-optimal rotation and results.
For example, you may find that your glide phase is much longer than 20 or 22 feet, which then lengthens your hook phase and you may never get into the roll phase. This can cause corner pins to stick instead of taking a knock.
The following graphic shows the three phases in a more visual form. As you will see, it shows the portion of the lane associated with each stage (as explained above), as well as pictures and a graphic of your bowling ball and how it behaves at each stage. We hope this picture helps you understand the concepts of ball movement and the skid, hook and roll phases. If you have any questions, let us know in the comments section below.
Source: Breaking Ball Motion, USBC Bowling Academy
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