This is today's Cue Ball Cheat.
This practice setup (and others in the book and blog) helps you dial an exact speed and spin. That will get perfect shape on the second ball. This is how you string a run together, one precise shot at a time.
Tangent line & speed
Every time you hit an object ball with a cue ball, there is a minor wonder of physics that occurs. That is known as the tangent line. What is amazing about this little bit of table billiards activity is that you can use it to predict cue ball behavior. Now that is an important and useful fact.
Here is how it works. Regardless of the speed of the cue ball and the angle that the cue ball and object ball contact*, the cue ball will travel away from the object ball and the contact point between them at right angles.
Sound a little too complicated? Let's use a couple of visual aids. In the example below, you will see a contact between the cue ball and an object ball. See the line going to the right and left of the touching point? That is the tangent line.
You can see from the line that the one ball will go into the corner pocket. What you also see is that the cue ball will scratch into the other corner pocket - not something you want to allow, unless there are other balls in the way.
So, what can you do? Most important - don't slam the object ball into the pocket. Use a lower speed. You have two options:
- Top spin ("follow"), combined with side spin. Use 10:00, 10:30, 11:00, 11:30, 12:00, 12:30, 1:00, 1:30, or 2:00.
- Bottom spin ("draw"), combined with side spin. Use 4:00, 4:30, 5:00, 5:30, 6:00, 6:30, 7:00, 7:30, or 8:00.
The lower speed allows the cue ball spin to interact with the cloth and force the cue ball away from the dangerous tangent line. Here is how to use that spin to get away from the dangerous tangent. With slower cue ball speeds, the follow options have the best success of missing the corner pocket.
Tangent thumb technique
This technique will help you calculate the probable path of the cue ball after it contacts the object ball. This can also help determine whether that path can or should be modified with cue ball spin.
After contact, when the cue ball travels to the right of the object ball, hold your left hand above the cue ball and form an "L". The index finger points to the pocket, the thumb will point to the cue ball path.
After contact, when the cue ball travels to the left of the object ball, use your right hand. The thumb will point to the cue ball path.
- With slower speeds, the cue ball has sufficient time to interact with the table cloth and deviate from the tangent line, either with draw or with follow.
- The more speed the cue ball is traveling on the tangent line, the more difficult it is to force any deviation from the tangent line.
When the angle is very shallow coming into the object ball, the cue ball will be difficult to force off the tangent line. (See the graphic.) It can be done, but your cue ball speed must be slow, and the spin must be at least 1-1/2 to 2 tips out from center. (It will help to practice working with this problem. There will be critical situations where a scratch looks almost certain. Knowing how to escape certain death is useful.)