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DeadCrab
05-30-2008, 07:28 AM
While twist banking (using english to compensate for differences in the incident and rebound angles) is in general disfavor, I found the method provided by Jimmy Reid (http://www.insidepoolmag.com/index.php?option=com_content&task=view&id=107&Itemid=568) to be very interesting.

Most authors tell you that you either have to increase cut angle or use outside english, but then it is "hit a million balls" time to figure out exactly how much compensation is needed for a specific shot.

If you plow through all the diamonds stuff in Reid's article, which you probably already know about, you get to the paragraph where he tells how much english to use.

I was skeptical, but gave it a try on my 7' home table last night. I'm just an intermediate player with limited english skills, but using backhand english to the degree advised by Reid, the balls fell into the pocket the way they should. What really impressed me, is that the method seemed robust with respect to cut angle, and OB-cushion and CB-OB distances.

I haven't had time to explore how it works with cross-banks or long-axis banks. For long short axis banks, the prescribed english may be more than I can deliver without miscue. But, my initial impression of Reid's approach is favorable, and players looking for a standardized method of bank compensation ought to give it a try.

Bob_Jewett
05-30-2008, 11:40 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DeadCrab</div><div class="ubbcode-body">
... What really impressed me, is that the method seemed robust with respect to cut angle, and OB-cushion and CB-OB distances.
... </div></div>
I'm certain that the distance between object ball and cushion will make at least half a diamond difference along the final long rail on where the ball lands. Of course, if you subconsciously correct for the OB-rail distance, you won't see the error. Try setting the shot up so it is a perfectly straight-on bank according to the system and only count those shots where you stop the cue ball dead on contact. If the cue ball drifts a ball or two to the left or right it will make a large difference in the bank result.

A minor quibble is that the numbers along the right rail are not "100% correct" as you will discover if you do the illustrated drawing very carefully on a large sheet of paper. Be sure to get the correct rail-nose to diamond space on your drawing.

Note that all of the shots in the system use "through" sighting rather than "opposite" for both the origin and the target. I think it is important to state this up front.

DeadCrab
05-30-2008, 12:49 PM
No question that my technique may have biased the results. Sometimes you can get the right result for the wrong reasons. But just for the sake of discussion...

When banks are compensated by changing the cut angle, everything changes; the angle of incidence, the bank point on the rail, the angle of rebound. For driving the OB down a given "natural bank" pathway, the cut angle used has to be different for varying distances between the banking rail and OB.

With english compensation, the angle of incidence and the banking point on the rail stay the same, and the banking point is the true geometric banking point. Assuming that the english used does not prevent you from accurately driving the OB into the geometric banking point, the question is whether or not the OB retains the acquired spin enough to get the desired effect when it hits the cushion.

On a 7' table, the CB-OB and OB-rail distances tend to be short, and presumably with less attrition of side spin on cross table banks.

Bob_Jewett
05-30-2008, 12:58 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DeadCrab</div><div class="ubbcode-body"> ... With english compensation, the angle of incidence and the banking point on the rail stay the same, and the banking point is the true geometric banking point. ... </div></div>
I believe this is false. Do you have a simple, convincing demonstration?

DeadCrab
05-30-2008, 01:34 PM
No, but that is what I'm trying to do. Hit the geometric banking point with the OB receiving spin transfer from the CB and subsequently taking a more favorable rebound angle.

How well I succeed at this is unknown. I could be getting an unintentional "cut". I might try to video it, but I don't know that my old analog camera will really decide the issue.

Might be a good experiment for someone with better stroke and aim.