Scott Lee said:
Well Bob...I will defer to your "physics junkie" knowledge,
Scott, you're being defensive here. You made a statement about swerve that's untrue, or at least that fails to recognize the amount of squirt varies a fair amount from stick to stick. Bob ever so gently corrected it. It's not a big deal.
Scott Lee said:
but imo the entire issue of squirt/swerve/deflection is so overused, overrated, and misunderstood, that it really doesn't matter much for most players.
I disagree strongly with this( OK, maybe not the misunderstood part). Squirt is actually the simpler of the two from a practical standpoint. It gets a lot of air time here in part because we are discussing what does or doesn't cause it and what are the strengths and pitfalls of different proposed ways to measure it. Most of this is not important to someone learning how to play pool. Swerve is the tougher egg to crack, because it depends on more things (elevation, cloth, shot speed, distance to object ball). Add in squirt and you have the correct aim for sidespin shots depending on all those things plus the stick you use.
Everyone is always looking for some excuse why the CB behaved differently from what they expected, and want to blame the cue or tip.
That may be true. But it really doesn't add or subtract to the issue here, imo.
Start with a repeatable stroke, and most of those issues just melt away as blue sky.Give me 10 minutes playing with ANY cue with a decent tip, and I can adjust so that I'll pocket the balls and get position just as well as with my own playing cue. jmo
OK, but again I don't see the relevance. You've got an internalized knowledge of the effect of shot speed, stick elevation, and cloth on swerve, how squirt is added to that to make a net adjustment, and the ability to adapt quickly to changes in squirt.
That's a good thing. It doesn't make these things unimportant..
I also know some very straight shooting players with strokes much more repeatable than mine who are lost for weeks on sidespin shots when their cue is out for repair.
Here is a description I gave to a beginner a while ago of different issues related to aiming with sidespin. Do you think this is unreasonable detail or too physics-junky-like for a beginner?
********************
(newbie question)
> My question, when applying english, I know my cue ball
> should be slightly off center[...] What I don't know is where
> the axis of my stick should be pointing.
> Do I aim as normal and then slide just the tip of my
> cue to put english on the ball, leaving the base of my
> stick where it is? Or do I move the whole axis of my
> cue parallel to my origial aiming point?
> Or maybe I'm asking the wrong question. Any advice on
> how to aim when applying english will help greatly.
You're asking an excellent question that unfortunately has a bit of a
complicated answer. First, a shot hit with sidespin is a fair amount
tougher than the same shot hit without sidespin, so consider adding
english only when the object ball is fairly close to the pocket and the
cueball is not too far from the object ball. The primary objective of the
english is to alter the angle of the cueball rebounding off the cushion.
There are three new things to consider when hitting with sidespin:
spin-induced throw, swerve, and squirt.
spin-induced throw: when a spinning cueball hits an object ball straight
on, the cueball surface rubs across the object ball surface and "throws" the object ball off course a little bit.
This is a small effect (due to the friction between the balls), but it's not small enough to be ignored. You will see this
effect plain as can be if you set up a shot with the object ball six feet
from the pocket and the cueball just four or five inches from the object
ball.
swerve: IF a cueball is hit with sidespin using a level stick, it will
move in a straight line. However, even though as-level-as-possible is the
goal, the stick is never really level. You are always hitting down on the
ball at least a little. Hitting down on the cueball when applying
sidespin generates "swerve." The cueball actually curves to the side you
are hitting on. If you hit easy, the cueball will curve a little bit
within the first few inches and then move in a straight line along the new
direction. If you hit harder, it will go further before curving. If you
hit harder still, or if the object ball is close, it may get it's job
done before curving. Adjusting for this is complicated and depends on the
cloth on the table. This is the reason I advised against using english
when the cueball has far to travel before hitting the object ball. You
will see swerve plain as can be just by hitting the cueball not too hard
the length of the table with an elevated cue and sidespin.
squirt: (also called cue-ball deflection) This is a tough one, in part
because it is different for different sticks. Imagine you hit a cueball
at 9:00 with a completely level cue (so there's no swerve), and you got to
the aim by lining up for a centerball hit and moving the whole cue
parallel till the tip is pointing at the 9:00 spot (your second
suggestion). IFF there was no squirt, the cueball would go in exactly the
same direction as the centerball shot would have (parallel to the line of
the stick). However, because the front of the stick on sidespin shots is
driven even more off to the side during the stick-ball collision, the
cueball must go off to the other side a bit. (Every action has an equal
and opposite reaction, or conservation of sideways momentum, or whatever
you want to call it). The result is the cueball goes off in a straight
line that is angled off a bit (as much as 3 or 4 degrees) from the line of
the stick. The magnitude of this effect is different for different
sticks.
So how about aiming? For the conditions I recommended as ripe for
english, squirt is the main problem. The move-the-stick-parallel
approach (your second suggestion) is not right for any cue. Your first
suggestion (pivot about the butt of the cue) is close to correct for the
extreme lowest squirt sticks available. The correct aim for most sticks
would be achieved by beginning with a stick lined up centerball, and then
pivoting the stick about some point between your bridge hand and the joint
of the cue. The optimum point is different for different sticks. If it
is, say, 15 inches back from the tip, then you would apply left english by
leaving that 15-inch point fixed and moving the buttof the cue to the
right until the tip is where you want it. Many sticks "pivot points" are
not too far behind the bridge hand for a longish bridge. So some people
actually aim centerball and then pivot about their bridge hand. This is
called aim-and-pivot (or sometimes backhand english).
Most strong players do not use any such system, in part because it's
awkward to pivot about the correct point, and in part because there are
swerve and throw to consider as well on many shots. Many strong players
who have been using the same cue for a long time have probably hit 100,000
shots with english using that cue. They develop a memory (an intuition)
of how to adjust depending on the the shot and the speed, etc. In fact
there are many strong players who would not be able to explain coherently
these effects and what they depend on, but they have a working knowledge
of what they need to do in actual situations. Some people swear by the
intuition/working knowledge as the true path to salvation and are
downright antagonistic of efforts to break it down and understand the
different effects. But the correct opinion [
] is that enlightenment
is a harmonic convergence of the yin and yang of knowledge and intuition.
Your knowledge and understanding is a guide for developing that intuition
and is profitably kept close by.
