Summary: Billiards Digest June, 2011
David Alciatore, PhD ("Dr. Dave") ILLUSTRATED PRINCIPLES
"Aim, Align, Sight - Part I: Introduction and Ghost Ball Systems"
Note: Supporting narrated video (NV) demonstrations, high-speed video (HSV) clips, and technical
proofs (TP), and all of my past articles, can be accessed and viewed online at
billiards.colostate.edu. The reference numbers used in the article help you locate the resources on
the website. If you have a slow or inconvenient Internet connection, you might want to view the
resources from a CD-ROM or DVD. Details can be found online at: dr-dave-billiards.com.
This is my first article in a series dealing with the important topics of aiming, alignment, and sighting.
Let's start with some definitions:
aiming: determining the line of the cue necessary to send the cue ball (CB) to the desired ghost-ball
(GB) position to cut the object ball (OB) the required amount for the shot.
alignment: how you position your body and head to best enable you to place and stroke the cue along
the desired line.
sighting: eye alignment and line of focus used to best visualize and achieve the desired aiming line.
Over the next few months, we will look at each of these topics in detail. This month, we will focus on the
basics of aiming.
Diagram 1 illustrates some important terminology. The ghost ball (GB) is the imaginary CB position at
OB impact that sends the OB in the desired "target direction." The "line of centers" through the GB and OB
define the necessary contact point (CP) for the shot. The required "aiming line" of the shot defines the