Re: Curving an Object Ball(Part V-Debunking the Myths)

In article
<33655bf1-f89b-4afc-8042-9e072b378688@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Bambu <dmanasseri@xxxxxxxxxx> wrote:

Except that the margin of error gets smaller the closer the balls
are together.  You don't want a small margin of error on the setup,
you want a big margin of error.

How does the margin of error get smaller because the balls are closer?
Either way the balls have to be spaced out off the rail perfectly, its
all the exact same ***.

Here is a way to understand this. Take Bob Jewett's shot setup.

http://CueTable.com/P/?@2AXeU2BbFk3IbHV2PXOa2UXeU3UXNU@

The distance between the 1-ball and the blocking ball is 1 diamond,
and the distance between the blocking ball and the 9-ball is 3
diamonds. On a perfect table with a perfect setup, if the 1-ball
just barely misses the 2-ball, then it would roll straight and also
just barely miss the 9-ball. Now consider moving the 1-ball 1mm
farther away from the cushion. Now, if the 1-ball barely misses the
blocking ball it would hit the 9-ball. The question is how much of
the 9-ball is exposed because you moved the 1-ball that 1mm? The
answer is that 3mm of the 9-ball becomes exposed because that is the
ratio of the two distances. Think of a lever pivoting about a
fulcrum point 1 ball radius away from the 2-ball, there is 1 diamond
distance on one side of the lever and 3 diamonds distance on the
other side of the lever. If the short side of the lever moves 1mm,
then the long side moves 3mm.

Now consider your shortened version of the shot.

http://CueTable.com/P/?@2AXdB2BbFk3IbHV2PXVH2UXdB3UXNU@

Now, the 1-ball is 2.25 inches from that fulcrum point, and the
fulcrum point is still 3 diamonds away from the 9-ball. On a 9ft
table, 3 diamonds is about 37.5 inches (each diamond is about 12.5
inches). Now, moving the 1-ball 1mm results in exposing 16.7 mm of
the 9-ball, or a little less than 3/4 inch.

In one setup that small displacement in the shot setup exposes 3mm
of the 9-ball, in the other setup that same small displacement
exposes 16.7mm of the 9-ball. That is how the margin of error
changes, and that is why your shot setup is more susceptible to
setup errors.

Hopefully, you aren't going to have 1mm of error on the setup, but
you might have some significant fraction of that each time you set
up the shot. Even 0.5 mm setup error will expose 8.35 mm of the
9-ball in your setup, while it exposes only 1.5mm in Bob's setup.
So you might fairly consistently hit 6 to 8 mm of the 9-ball every
time you shoot your shot, and you would think that you are curving
the object ball 6 to 8 mm, when in fact you tapped the balls in
place slightly off when you set up the shot originally, and you are
just seeing the amplified effect of that setup error.

And, all of that still assumes a perfectly level table, perfectly
round balls, and a perfectly clean cloth. All of these things
introduce different kinds of noise into the whole measurement
process, some with a consistent bias some more or less random. Or,
say you shoot one shot and it barely misses the 9-ball, and then the
air conditioner fan kicks on, and the next time you shoot the same
shot the air current blows the ball over a couple of mm and it hits
the 9-ball. As far as object ball curve, that would be another
false positive.

And we have all played on tables where the side cushions were not
straight. The most obvious effect of this is that you cannot shoot
balls down the cushion past the side pocket, they always catch the
corner of the cushion at the pocket and miss. If you just get down
and sight along the cushion edges you can sometimes see that they
are off by several mm. If you shoot your sensitive shot on a table
like that, then, as far as object ball curve, that would be another
kind of false positive.

As I said before, you want to have shot setups with large margins of
error, not small margins of error. You don't want the noise to
drown out the signal. By moving the balls closer together like you
did in your shot setup, you have only decreased the margin of error,
you have not made anything possible as far as curving object balls
that was not possible before. If you can curve an object ball, then
you can shoot Bob's shot successfully. If you can't shoot Bob's
shot successfully, then you can't curve an object ball.

$.02 -Ron Shepard
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