SQUIRT FAQ
(from Ron Shepard's "Everything You Always Wanted to Know About
Cue Ball Squirt, But Were Afraid to Ask")
1. How can squirt be minimized?
By reducing the tip offset or by using a cue stick with a
small endmass.
2. Does shaft flexibility affect squirt?
No, not directly. Shaft flexibility may affect the endmass
and thereby affect squirt indirectly, but this is probably a
relatively minor effect. This means that the player is able
to choose a cue with a desired amount of shaft flexibility
for other reasons, without having to compromise the squirt
characteristics.
3. Does tip curvature affect squirt?
No, not according to the above analysis, except for the fact
that the tip curvature affects the actual tip offset for a
given shaft offset. However, there are data at the Predator
web site that suggests that a rounder tip (i.e. a dime
radius compared to the larger nickel radius) reduces squirt.
4. Does squirt depend on shot speed?
No, not directly. Shot speed might affect the endmass, but
this is probably a relatively minor effect. The observation
that different aiming is required for different shot speeds,
particularly on longer shots, is probably due to cue ball
swerve, not to squirt.
5. Does squirt depend on the cue stick weight?
Yes, but only when it affects the endmass. Weight added more
than about 10? away from the tip apparently has little
effect. This means that the player is free to choose stick
weight for other reasons without compromising squirt
characteristics.
6. Does squirt depend on the stick balance point?
Yes, according to the rigid cone approximation, but only
because it has a small effect on the endmass.
7. Do ivory or brass ferrules have more squirt than synthetic
materials?
If so, it is primarily because of the density of the material
and the resulting effect on the endmass. It appears unlikely
that the hardness or other physical characteristics affect
directly the squirt. However, a thick brass ferrule will
probably have more squirt than a thin brass ferrule. Also,
some ferrules are attached to the shaft with a metal screw or
stud; these cues probably have larger squirt than an
otherwise equivalent cue with a standard wood tenon.
8. Does the tip diameter affect squirt?
Yes, because smaller tips will have smaller endmass, all
other things being equal. This trend is predicted by the
rigid cone model. However, there are other ways to reduce
endmass than by using a small tip diameter, such as the
approach used by the Predator design.
9. Does tip hardness affect squirt?
No, not according to the above analysis. This also suggests
that the tip-ball contact time, which is related to tip
hardness, does not directly affect squirt, but this has not
been proven independently, and it is possible that contact
time does play at least a minor role in determining the
effective endmass through speed-of-sound mechanisms. To the
extent that tip hardness is independent of squirt, this means
that the player is free to choose tip hardness based on
personal preference without compromising the squirt
characteristics.
10. Is squirt caused by the tip slipping on the ball?
No, squirt occurs even when the tip does not slip. The tip
does not slip on normal shots.
11. Are there any stroke techniques that can be used to minimize
squirt?
No, not unless the technique somehow reduces the tip offset,
in which case the same shot could have been achieved simply
by stroking normally and using the smaller tip offset in the
first place.
12. Is it better to use an open bridge than a closed bridge?
It is possible that a tight closed bridge might increase the
effective endmass, and thereby increase squirt, but this is
probably a very minor effect.
13. For a given cue stick, will snooker balls squirt more than pool
balls, and will carom balls squirt less?
There are two separate effects, mass and ball diameter. Due
to the ball/tip mass ratio, the lighter snooker balls will
tend to squirt more than pool balls, and the heavier carom
balls will tend to squirt less. Futhermore, the stick pivot
point depends on the ball radius, so, for a given relative
tip offset and ball/tip mass ratio, the larger balls will
tend to have longer stick pivot points.
14. If I use a low-squirt cue, must I suffer from excessive or sensitive
sidespin?
All other things being equal, high-squirt cues will appear to
get slightly less spin (and speed) than a low-squirt cue for
a given tip offset, but this is a very minor effect, smaller,
for example, than the differences in tip curvature between
two tips might affect the amount of sidespin.
15. Does the amount of shaft bend, buckle, or vibration affect squirt?
No, the shaft is set into motion as the tip strikes the ball,
but the actual bending and/or buckling occurs after the short
tip-ball contact time. If the ball has already separated
from the tip before the bending occurs, then the bending and
buckling can have no effect on the ball.
16. Must I trust the advertising of the cue makers to tell me how much
squirt a stick will have?
No, the aim-and-pivot squirt test is a reliable way to
determine squirt, it requires no special equipment, and with
a little practice, it can be performed by anyone with a
reasonably straight stroke.
17. What is the optimal squirt characteristics for a break cue?
The stick pivot point should be at the bridge length. For
most players, this will be typically in the 14-inch to 16-
inch range.