Pulling it together

Figure 1
This is the final post of my seven part series to improve your game. Today I will pull together all the pieces we have studied and show you how to apply what we learned to play the perfect game of pool. As a review, here are the individual components that we worked on:
1. Aiming shots with the Ghost Ball method
2. Calibrating our arm to control the speed of a shot
3. Predicting the cue ball deflection angle after collision with an object ball
4. Predicting the cue ball rebound angle after it hits a rail cushion
5. Adjusting the speed of a shot to compensate for energy lost in the cue ball / object ball collision.

Figure 2
Now, let’s get down to business! Take a look at the table layout in Figure 1. This is a game of eight ball, we are stripes, and we have only one stripe ball left to pocket. What we want to do is pocket the fifteen ball, then make the cue ball travel around the table to get into position for the final shot, which is the eight ball. That looks like a pretty hard shot doesn’t it? How do we make it happen? Should we just hit it hard and hope for the best? Heck no! With the knowledge that you now have, and with the countless hours you spent calibrating your arm in part 3 of this series, you should be confident and totally in control!
Let’s analyze the shot. First, we need to figure out how to make the fifteen ball go into the pocket. We will use the Ghost Ball aiming method. See Figure 2, where we have imagined the Ghost Ball, and determined the aiming point. Notice the aiming line that extends through the ghost ball. The aiming line just barely touches the edge of the object ball. If you refer to the Angle of Deflection chart in part 4 of this series, you will see that this is a half ball hit. According to the Deflection chart, the Angle of Deflection will be about 30 degrees, so in your mind’s eye, see the “Peace Sign” to determine the initial direction of the cue ball after collision.

Figure 3
In Figure 3, we utilize the Angle of Reflection from part 5 of this series to estimate the path of the cue ball after collision with the first rail and subsequent rails. Based on the extension of this “natural” path, we should check to see if any of the solid balls are going to get in the way. Fortunately, in this case, none of the balls are in our way. Yippeee! This means there’s no need for us to use extra cue ball spin to avoid unwanted collisions! Now we can just hit the ball and try to make it land it somewhere near the spot marked “X”. But wait a minute. Do we really need to be that exact? Take a look at Figure 4, and notice the position of the eight ball and the blue line that I drew on the table which outlines a “safe” zone highlighted in yellow? As long as the cue ball lands anywhere in this yellow zone, you should be able to make the final shot and win the game fairly easily; therefore, there’s actually a pretty large margin for error on this shot.

Figure 4
Now the question is: “How hard do I need to hit the cue ball in order to make sure it stops in the yellow zone?” If we extend the cue ball path through the yellow zone, we can put limits on how soft and how hard you can hit the cue ball. See Figure 5. The point marked “A” is the softest you can hit, and point B is the hardest you can hit. But wait, we get a bonus! If the cue ball makes it all the way to point B, it will collide with the green ball and come to a stop. The green ball will act as a stopper to keep the cue ball safely within the yellow zone. As such, we can actually hit the cue ball even harder, and still be able to keep the cue ball in the yellow zone. We could probably hit the cue ball hard enough to theoretically make it to point “C” (if the green ball were not in the way). Now, let’s calculate the distances the cue ball would have to travel to get from its starting point to points “A” and “C”. The distance to point “A” is ~10 diamonds. The distance to point “C” is ~16 diamonds. If you refer back to the exercise from part 3 of this series, this translates into an arm stroke with a speed between 3 and 6.

Figure 5
So we want to hit the cue ball with an arm speed between 3 and 6, but remember, today we are also hitting an object ball with a ½ ball hit. As such, the object ball will be ‘stealing’ some energy from us, so we need to make an adjustment for that. According to the “Speed after Collision” chart from part 6 of this series, the object ball will take 4 parts of the cue ball’s energy, and the cue ball will retain about 3 parts of its energy. Just to make the math easy, let’s assume the energy split is 50/50, even though it’s really about 57/43. This means that the cue ball will only retain about half its energy after it hits the object ball. In order for the cue ball to end up with enough speed to get into the yellow zone, we will need to multiply our calculated speed range by two, since object ball will steal about half of the cue ball’s energy. So the modified distances are 20 diamonds for point “A” (10 x 2) and 32 diamonds for point “C” (16 x 2). This translates into newly calculated arm speeds of 8 (minimum) and 14 (maximum).
After you’ve done all the thinking and calculating, let’s review the final answer: In order to hit the perfect shot, you will need to do the following:
- Use a half ball hit on the object ball
- Hit the cue ball with normal ‘running’ English
- Hit the cue ball with an arm speed between 8 and 14.
That’s it! At this point, there’s nothing else to worry about. Just get into your stance, use proper fundamentals, and execute the shot with the proper speed. If you take your time and go through this type of analysis on every single shot, you should be running tables in no time. Nothing to it!