I recently had a student ask, "How can I tell how far the cue ball will travel after it hits the target ball?" Good question, but I didn't have a pat answer. Here is a basic technique I developed for her.

My initial reaction was hide behind the tried and true, "you will have to determine that yourself through trial and error." That answer did not suit me. It seemed like a question I should be able to answer and yet I could not recall ever seeing it mentioned in any book or video. I have been working on my cue ball speed for years with the 2-7-2 series by The Monk. His explanation involves using the cue ball by itself from center table, traveling 3 cushions to return to center.

But how far will the cue ball travel after a medium stroke at a 45 shot, where it sinks a target ball in a corner pocket? Once you know this, it is much easier to envision its travel on other shots of various speeds and angles.

Experienced players will often advise "you just have to get a feel for it". That does apply to many areas of the game, but it doesn't necessarily have to apply to all. After all, that was probably the stock answer regarding where the cue ball travels after hitting the object ball until someone discovered the tangent line.

I went to the table and began to experiment with various shots, and tried to think through the process. I decided it was logical to base the experiment on 2 basic concepts; a 45 cut shot, and the medium speed stroke associated with the End Rail Stroke Drill I suggest all students learn and use regularly.

My medium speed End rail shot is good for about 9 diamonds after rebounding from the end rail.

Since the range of makable shots is between 0 (a straight in shot) and 90 (the thinnest cut), a 45 cut shots is the middle ground. And since the medium speed shot is a known reproducible shot, even for beginners, those two factors combine to produce a good baseline for predicting cue ball travel.

Try it yourself.

1. Set up an object ball for a corner pocket.
2. Place the object ball 1 diamond from each cushion.
3. Place the cue ball about 4 diamonds straight up-table to produce a 45 shot into the corner pocket.
4. Make the shot at he medium "Stroke Drill" speed and note where the cue ball comes to rest.
5. Repeat several times to produce a reliable average.

My guess, based on the fact that the medium stroke is about the same for all of us, is that the cue ball will travel about 8 diamonds. Mine is actually 7 diamonds if you count 3 across the short rail and four from there to about mid table on the long rail. You may wish to think of it as about one table length or 2 half-table lengths; whichever makes more sense.

Whatever number you come up with in your tests, the fact is that you now know, in real numbers, what happens on this shot. Some find that information is all they need to understand cue ball travel at different angles and speeds. Others go on to experiment with other angles and speeds to get a more complete picture of how all of the variables tie together.

Try it for yourself and see if doesn't put things a better perspective.