Trsect Bisect... It's All In Perspective.

[RSB-Refugee]

Trisect, Bisect... It's All In Perspective.

My Billiards Digest arrived today! How many times is David Alciatore Ph.D., going to tell us that a cue ball's draw path can be determined by trisecting. He would have let this theory go a long time ago, if it were not meeting a great deal of resistance.

Here is why I say bisect, rather than trisect. On page 36 Diagram 1, Draw two lines, Post-Its work real well for this. The first line will be parallel to his final cue ball direction line and will run straight through the point where the ghost ball is touching the object ball. The second line will run from the center of the cue ball origin to the point where the ghost ball contacts the object ball.

I know the only difference is in how you percieve it, but I feel mentally calculating a bisector is much easier than a trisector. Also when calculating his trisector, you must acuurately judge the center of the ghost ball. With his method, you also must predetermine a path for the object ball, if that path does not send the cue ball on its intended line, you must recalculate. Remember, when playing safe or trying to ride the cheese , you only care what the cue ball is doing.

I am not saying he is wrong, but he and I definitely look at the same thing in two very different ways.

Tracy

 

[Jal]

One difference between the bisect, double bisect and trisect methods is that the first two are a little bit dependent on the distance between the cueball and object ball, even assuming you get the draw spin just right. Using the cut angle as with the trisect method makes this irrelevant. It doesn't seem that hard to me to visualize this angle since it's the difference between the initial cueball and final object ball directions, ignoring throw. Throw, though, is pretty small given the "typical" amount of draw on the cueball for which these geometries apply.

There is another fairly simple geometrical way of determining the cueball's final direction when it has any amount of draw or follow on it. But with all of these methods you have to know the amount of spin it retains (or develops) as the cueball arrives at the OB - the sixty-four thousand dollar question.

...He would have let this theory go a long time ago, if it were not meeting a great deal of resistance.

Could you tell me where he's getting this resistance? (I'm not questioning that he is getting it).

...I know the only difference is in how you percieve it, but I feel mentally calculating a bisector is much easier than a trisector.

I expect you're right.

Jim

 

[RSB-Refugee]

But with all of these methods you have to know the amount of spin it retains (or develops) as the cueball arrives at the OB - the sixty-four thousand dollar question.

I agree, the spin to speed ratio does complicate the issue.

Could you tell me where he's getting this resistance? (I'm not questioning that he is getting it).

It was speculation on my part and I should not have mentioned it. I was trying to illustrate how different people can look at the same thing, but not see the same thing.

Tracy