## Aiming 101 - How Accurate is Accurate Enough?

### Aiming 101 - How Accurate is Accurate Enough?

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"):

POCKET SIZE
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:

POCKET SIZE
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
system.]

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.

Pat Johnson
Chicago

### Aiming 101 - How Accurate is Accurate Enough?

I'm not 100% sure of what point you are trying to make.  I have a little
difficulty reconciling Hal's theory in my mind but experience has taught me
never to say someone can't do something.  When I was in the army I met a kid
who had some illness when he was young that had affected his ears, somehow he
wound up with perforated eardrums but his hearing was fine.  He used to go in
bars and bet people he could blow smoke out his ears, talk about drinking a lot
of free beer.  Never say "it can't work".

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> I'm not 100% sure of what point you are trying to make. ...

I think Pat is pointing out that if you believe in geometry, you
need more than 3 angles to play pool.  Think of it as a handicap
for geometerians.

Many people don't believe that geometry applies to their world,
and maybe it doesn't, and maybe they can get by with only three
angles.  For those people, Pat's tables are worse than useless.
But please don't misunderstand me.  I'm not calling those people
evil -- a belief in geometry is probably not a requirement to get
into Heaven.  However, it is as useless to discuss geometry with
them as to discuss Immanuel Velikovsky's cosmology with Britney
Spears.  And to those people, (Spears and Velikovsky included) I
apologize for believing in geometry and physics.

--

Bob Jewett
http://www.sfbilliards.com/

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> I'm not 100% sure of what point you are trying to make.

I'm not trying to make a single point.  Since there has been some recent
discussion of aiming systems, I want to explore how and why they work or
don't work.  This is the first post in a short series about that.  This
first installment attempts to define what any system must accomplish:
the minimum accuracy necessary to make shots.

This isn't about Hal's system only - his is just a convenient, familiar
example.  For that matter, we don't really know what Hal's system is or
if it even exists.

Pat Johnson
Chicago

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> > I'm not 100% sure of what point you are trying to make. ...

> I think Pat is pointing out that if you believe in geometry, you
> need more than 3 angles to play pool.  Think of it as a handicap
> for geometerians.

> Many people don't believe that geometry applies to their world,
> and maybe it doesn't, and maybe they can get by with only three
> angles.  For those people, Pat's tables are worse than useless.
> But please don't misunderstand me.  I'm not calling those people
> evil -- a belief in geometry is probably not a requirement to get
> into Heaven.  However, it is as useless to discuss geometry with
> them as to discuss Immanuel Velikovsky's cosmology with Britney
> Spears.  And to those people, (Spears and Velikovsky included) I
> apologize for believing in geometry and physics.

I don't think that most resonable people would argue that there are
physical laws that govern what happens.  I look at in more of a
different way to relate to the objects that achieves the same result.
Because of the margin or error that is present because the hole is
larger than the ball it is possible to hit areas rather than prescise
points to pocket the ball.

I don't know much about Hal's three angle approach. I do know that,
for me, the ball to ball aiming method and backhand english works.  I
still don't understand WHY it works but I make more balls now than I
did before.  So put me on the infomercial at 1:00am along with the
ones who didn't do well at geometry but can understand how to aim one
ball into another.

John

### Aiming 101 - How Accurate is Accurate Enough?

John sazs

Quote:
> Because of the margin or error that is present because the hole is
> larger than the ball it is possible to hit areas rather than prescise
> points to pocket the ball.

All well and good on loose equipment, I suppose.

Lately I've been playing at a room with very tight equipment  --  can't
touch the rail on the way in and even hitting too far to the outside of the
pocket will result in a miss.  In this situation, three angles will not
suffice.

Lou Figueroa

Quote:

> > > I'm not 100% sure of what point you are trying to make. ...

> > I think Pat is pointing out that if you believe in geometry, you
> > need more than 3 angles to play pool.  Think of it as a handicap
> > for geometerians.

> > Many people don't believe that geometry applies to their world,
> > and maybe it doesn't, and maybe they can get by with only three
> > angles.  For those people, Pat's tables are worse than useless.
> > But please don't misunderstand me.  I'm not calling those people
> > evil -- a belief in geometry is probably not a requirement to get
> > into Heaven.  However, it is as useless to discuss geometry with
> > them as to discuss Immanuel Velikovsky's cosmology with Britney
> > Spears.  And to those people, (Spears and Velikovsky included) I
> > apologize for believing in geometry and physics.

> I don't think that most resonable people would argue that there are
> physical laws that govern what happens.  I look at in more of a
> different way to relate to the objects that achieves the same result.
> Because of the margin or error that is present because the hole is
> larger than the ball it is possible to hit areas rather than prescise
> points to pocket the ball.

> I don't know much about Hal's three angle approach. I do know that,
> for me, the ball to ball aiming method and backhand english works.  I
> still don't understand WHY it works but I make more balls now than I
> did before.  So put me on the infomercial at 1:00am along with the
> ones who didn't do well at geometry but can understand how to aim one
> ball into another.

> John

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

>> > I'm not 100% sure of what point you are trying to make. ...

>> I think Pat is pointing out that if you believe in geometry, you
>> need more than 3 angles to play pool.  Think of it as a handicap
>> for geometerians.

>> Many people don't believe that geometry applies to their world,
>> and maybe it doesn't, and maybe they can get by with only three
>> angles.  For those people, Pat's tables are worse than useless.
>> But please don't misunderstand me.  I'm not calling those people
>> evil -- a belief in geometry is probably not a requirement to get
>> into Heaven.  However, it is as useless to discuss geometry with
>> them as to discuss Immanuel Velikovsky's cosmology with Britney
>> Spears.  And to those people, (Spears and Velikovsky included) I
>> apologize for believing in geometry and physics.

John sez

Quote:
>I don't think that most resonable people would argue that there are
>physical laws that govern what happens.  I look at in more of a
>different way to relate to the objects that achieves the same result.
>Because of the margin or error that is present because the hole is
>larger than the ball

and then

Quote:
>it is possible to hit areas rather than prescise
>points to pocket the ball.

not really - the ball hits a point
if you mean there is a margin of error represented by an arc on the ball
<that damned geometry again> rather than one single point,
that would be correct

Quote:

>I don't know much about Hal's three angle approach. I do know that,
>for me, the ball to ball aiming method and backhand english works.
>I still don't understand WHY it works but I make more balls now than I
>did before.

why it works is:

you are concentrating on a target<area>thereby focusing your attention

when the target amd/or you BHE is 'wrong'<as they often will be> you make
an unconcious adjustment<because of personal experience> so the ball
will go into the pocket instead of where it would go if you had done what
you thought you were doing

I was truly amazed when I learned how many people play this way
especially since most of them could pocket balls better than I could
- back then

Dale

So put me on the infomercial at 1:00am along with the

- Show quoted text -

Quote:
>ones who didn't do well at geometry but can understand how to aim one
>ball into another.

>John

### Aiming 101 - How Accurate is Accurate Enough?

Robert Meucci has this to say about accuracy:

"How accurately do you have to hit the object ball to make a simple spot
shot from the head string on a 4 1/2 x 9 ft. table?

The object ball must be struck no more than 2 1/8 degrees off-line in either
direction for a total strike zone of .083 inches (slightly more than 2mm on
the surface of the cue ball). In order to hit that target you must not shoot
the cue ball more than 1/10 of 1 degree off-line (about 6 minutes of angle).

What if you had to make a reasonably simple combination shot like this to
win a match: the 9 ball lays 3 feet from the corner pocket, the 8 ball is
only 2 feet from the 9 ball and the cue ball is just 3 feet away from the 8
ball.

In this scenario the 9 ball will have to be struck within .070 inches (a
little more than 1/16 of an inch) to allow for the 2 1/4 inches of slop in a
4 1/2 inch wide pocket.

Therefore, the strike zone on the 8 ball is only .0029 inches. This small
target is equal to the thickness of a human hair. In order to hit it from
only 3 feet away with the cue ball, it will have to be shot so precisely, it
is equal to bracing a rifle in one's front hand on a solid rest using only
the barrel to aim with (no sights), firing and hitting a bullseye 5 1/4
inches in diameter one mile away!

Simple, huh! Yet, great players actually accomplish this 1 out of 5 times."

http://www.meuccicues.com/accurate.htm

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> Robert Meucci has this to say about accuracy:

> ... to make a simple spot shot ... on a 4 1/2 x 9 ft. table
> ... a total [OB] strike zone of .083 inches [~

This more or less agrees with my table for a 36" shot to a 4.5-5" pocket
(a spot shot on a 9-footer is about 35-1/3" -- .083" = ~2.5/32" strike
zone), which is what I call an "average shot".  This size strike zone is
about 1/20 of 1/4 of the OB's circumference, so you have to be about 3
times as accurate as a "3-angle" system can be.

Pat Johnson
Chicago

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

>Lately I've been playing at a room with very tight equipment  --  can't
>touch the rail on the way in and even hitting too far to the outside of the
>pocket will result in a miss.  In this situation, three angles will not
>suffice.

>Lou Figueroa

You need to upgrade to the six angle system for tight pockets, it is much
more precise!  :-)

Cheers,
Jim

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> for me, the ball to ball aiming method ... works.

What is it?

Pat Johnson
Chicago

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> John sazs
>> Because of the margin or error that is present because the
>> hole is larger than the ball it is possible to hit areas
>> rather than prescise points to pocket the ball.
> All well and good on loose equipment, I suppose.
> Lately I've been playing at a room with very tight equipment --
> can't touch the rail on the way in and even hitting too far to
> the outside of the pocket will result in a miss.  In this
> situation, three angles will not suffice.

What John doesn't seem to understand is that your aiming needs to
get you not to just to the neighborhood of the pocket, but on
average to the center of the pocket.   Otherwise, you're giving
up maybe double or triple the number of misses to your opponents
who have a system (even if that system is simple gut feel) that
does center their shots on the center of the pocket.

As for the general question of required accuracy to make a shot,
it's been discussed here before in terms of how much error you
can have in the position of your backhand (assuming you strike
the cue ball in the center) in order to make the shot.  The
result is:

The difficulty of a shot can be found as follows.  Take the
distance from the object ball to the pocket in diamonds.
Multiply it by the distance from the cue ball to the object
ball in diamonds.  For example, a spot shot is 2.8*4.5 = 12.6
more or less.  This is the difficulty due just to the distance
involved.  To include a factor for the cut angle, divide the
"distance only difficulty" by the cosine of the cut angle.
For a spot shot, which is about 30 degrees, that gives a
total difficulty of 14.6.

The total allowed error in the position of the backhand in
inches is given by taking 1/difficulty with the answer in
inches.  That means that for a spot shot, you alignment must
get the backhand correct to within a 1/16th inch window, or
+- 1/32nd inch.

It is amazing that anyone can make a ball. 1/16th of an inch is
the thickness of a US five-cent piece.

Of course, the above depends on the size of the pockets, and the
approach angle to the side pockets, and whether the pockets
tighten for hard shots, and whether the cloth is new and a
million other factors, but it is a good guide for the relative
difficulty of shots on the same table.

--

Bob Jewett
http://www.sfbilliards.com/

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> > for me, the ball to ball aiming method ... works.

> What is it?

> Pat Johnson

I thought you knew everything about everything Einstein, and I guess
if Hal wanted you to know, he would have told you already.  So here's
a clue:
All answers to the problems of the Universe are in the heavens.  Look
to the sky and various cellestial bodies.  Your understanding and
acceptance of this is forever eclipsed by your own omniscience which
is the issue in your trying to get the edge on everyone and run
circles around them. Stay centered for a while.  If you read this as
I've written it, you still won't get it.  The answers are within the
post with key words.  Right John?
Now Einstein, put your pea brain to good use for a change.

..................Billy

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> ... If you read this as I've written it, you still won't get it.

That's a given.

pj
chgo

### Aiming 101 - How Accurate is Accurate Enough?

Quote:

> >Lately I've been playing at a room with very tight equipment  --  can't
> >touch the rail on the way in and even hitting too far to the outside of the
> >pocket will result in a miss.  In this situation, three angles will not
> >suffice.

> >Lou Figueroa

> You need to upgrade to the six angle system for tight pockets, it is much
> more precise!  :-)

> Cheers,
> Jim

WRONG AGAIN, JIM AND LOU. I USE ONLY ONE ANGLE OF AIM. THE MAGIC IS
WHAT I DO WITH THE CUE.