Aiming is getting the cue ball (CB) and object ball (OB) visually
aligned (overlapped to a certain degree when viewed from the perspective
of the shooter) so that if they make contact with that same alignment
the OB will be driven to the intended target. This is the same as
saying we aim to make the CB contact the OB on a certain spot (or within
a certain area) on its surface.
The target for the OB is usually a pocket, and the pocket is bigger than
a ball (usually bigger than two balls), so there's some room for error -
the CB must contact the OB within a small area on the OB's surface, but
not on a precise point. The "OB contact area" is bigger when the OB is
closer to the pocket and smaller when the OB is farther from the pocket.
Size of OB contact area for various OB-to-pocket distances and pocket
sizes (rounded to nearest 1/32"):
4.0" 4.5" 5.0"
OB -> POCKET = 12" 5/32" 7/32" 8/32"
OB -> POCKET = 24" 3/32" 3/32" 1/8"
OB -> POCKET = 36" 1/16" 1/16" 3/32"
OB -> POCKET = 48" 1/32" 1/16" 1/16"
OB -> POCKET = 60" 1/32" 1/32" 1/16"
Number of contact areas on 1/4 of the OB's circumference:
4.0" 4.5" 5.0"
OB -> POCKET = 12" 11 8 7
OB -> POCKET = 24" 22 17 14
OB -> POCKET = 36" 32 25 21
OB -> POCKET = 48" 43 34 27
OB -> POCKET = 60" 54 42 34
This means that for a 1-foot shot into a 5-inch pocket (the easiest shot
on the list) you have to hit an OB contact area that's 1/7 of the area
visible on its left or right side (depending on which way you want to
cut the shot). For a 5-foot shot into the same pocket you have to hit a
CB contact area that's 1/34 of the area visible on its left or right side.
To put this information into a familiar context, let's compare it with
Hal Houle's "3-angle" system, in which he says any OB can be pocketed
using 1 of only 3 predetermined CB/OB alignments. This is clearly not
the case for making an OB straight into a given pocket at any distance
over 1 foot - for an "average" shot, you have to have to use the right
one of about 20 CB/OB alignments! [We're not sure exactly what Hal
means by his statement, so this isn't necessarily a criticism of Hal's
What does this tell us about how we aim and how aiming systems work (or
don't work)? See "Aiming 102" in a future post.