I've seen Larry Nevel cut a ball using inside English that seems impossible. I haven't gotten a chance to ask him how he does it, but it appears he curves the ball slightly using inside. Maybe he'll share his secret here.
Maniac said:I'd like to see what answers I can get from azb'ers out there on what their opinion is (or scientific fact) they can give me on what the lowest possible angle of a cut shot is possible. There obviously are gonna be two categories here, the middle-of-the-table cut shot, and the cut shot where the object ball is frozen on a rail. Let me hear your opinions and/or examples of real-life shots.
I realize that there isn't a way for most of us to measure what angle of a shot we may have made, so an honest estimate is fine.
Maniac
Jude Rosenstock said:I simply cannot see how that would physically be possible. I mean, forget pool. There are rules to physics. If you don't have line-of-site, you can't hit the contact point necessary to produce such an angle. Aside from jumps and masses (yes, fun stuff), you need to be able to see your contact point. anything less than 90 degrees and you're talking about a point that's on the other side of the object-ball.
Although you can throw a ball a few degrees, this is really only evident when you're hitting a meatier part of the object-ball. The thinner the cut, the less of an influence english will have. There simply isn't very much friction happening when two balls come in contact so spin becomes trivial at steep angles.
To be a nitpicker, if you go rail first on a cut shot, the true cut angle is not the incoming angle to the rail, since the CB is cutting the OB from the other side (rail side). The true cut angle the CB makes with the OB on contact, if you go rail first, should be close to (but less than) 90 degrees, even if the incoming angle is greater than 90 degrees.jay helfert said:...My opinion is that a ball can be cut as much as 120 degrees, if it is frozen to the rail. Yes, you must go rail first with extreme inside english, but it is a cut shot.
Outside of the box -> A ball can be cut over 90° if the cue ball leaves the surface of the table. That is, if the cue ball lands on the back side of an object ball, the object ball will, in essence, travel in a "negative" direction.Maniac said:I'd like to see what answers I can get from azb'ers out there on what their opinion is (or scientific fact) they can give me on what the lowest possible angle of a cut shot is possible. Maniac
jay helfert said:My opinion is that a ball can be cut as much as 120 degrees, if it is frozen to the rail. Yes, you must go rail first with extreme inside english, but it is a cut shot. As for cutting balls out on the table, a 90 degree cut may actually be possible, by using extreme throw english. That is, by using excessive right hand english, and hitting the object ball wafer thin, you may succeed in cutting it to the left a full 90 degrees.
I'm not going to bet on this shot....yet.
Yes, it's possible to cut a ball 180 degrees this way. The shot, however, is not practical in any reasonable situation. This was discussed in the previous thread that was more or less about this topic:td873 said:Outside of the box -> A ball can be cut over 90° if the cue ball leaves the surface of the table. That is, if the cue ball lands on the back side of an object ball, the object ball will, in essence, travel in a "negative" direction.
-td
Bob Jewett said:Yes, it's possible to cut a ball 180 degrees this way. The shot, however, is not practical in any reasonable situation. This was discussed in the previous thread that was more or less about this topic:
http://forums.azbilliards.com/showthread.php?t=38109
I think it's reasonable to restrict the discussion to shots that can be made at least 10%-20% of the time. Here's the open-table setup I tried: put the object ball on the center spot (exactly between the two side pockets, not usually marked on tables). Put the cue ball on the head string. See how close you can get the cue ball to the head spot and still cut the object ball in the side. My best for a reasonable percentage (about 15%) was 80 degrees.
If anyone wants to try this and report the result, just let us know how close the cue ball was to a ball spotted on the head spot and I'll do the geometry to find the angle.
Oh, and with a masse shot, it's possible to cut a ball more than 180 degrees. The cue ball can go out on the left side of the object ball and reverse and come back on the right side. I'd say that counts as more than 180 degrees of cut.
If the object ball goes into the center of the side pocket, shooting with the cue ball on the head spot, it is clearly more than a 90 degree cut. (About 3 degrees more, I think.)Tennesseejoe said:... If I put the object ball on the center spot and the cue ball on the head spot and cut the object ball in the side pocket:
1. Would that be a 90 degree cut or more than a 90 degree cut?
2. Should the cue ball be placed one ball width to the side of the head spot to be 90 degrees?
Jal said:Are we all in agreement that the cut angle is measured from the cueball's direction and not from the line of centers between the balls in their pre-shot positions?
Actually, and this surprised me when I first realized it, theory preidicts that maximum throw increases with cut angle. If you keep the cueball's speed constant and adjust your english to get the most throw, the largest amount occurs as you approach 90 degrees.
Against this, throw decreases with cueball (surface) speed, and at these cut angles you definitely need a lot of speed to propel the object ball.
Still, it predicts that at a cut angle of 85-90 degrees, with a cueball speed of 12 mph, which is pretty fast, you can throw the object ball backwards along the tangent line by 5 degrees. And you can probably add another degree from the rotation of the tangent line due to the compression of the balls.
But there is a catch: the difference in english which results in throwing the object ball maximally forward along the tangent line, not throwing it at all, or throwing it maximally backward, shrinks with increasing cut angle. Getting the spin just right becomes very difficult near 90 degrees.
Jim
roncook said:I cut (2) balls backwords on a 5x10' snooker table with a curve shot as
follows:
Frozen on the rail the cue ball & object ball, you have seen the cue ball
at one end of the table on the middle diamond & the object ball also in the middle of the table, people shoot this one all the time at 90 degrees and make the object ball.
Here is what I did: Move the object ball to the left diamond on the back rail and the cue ball at the opposite end of the table frozen on the right
diamond, I cut (2) object balls backwords to the right side of the table
into the right corner pocket.
"POOL TABLE"
__________________
Object ball is here """o"" (Frozen on left diamond)
"o" (Cue Ball is here, frozen on right diamond)
__________________ ... I made (2) balls in this corner pocket on a 5x10 snooker table
Bob Jewett said:If the object ball goes into the center of the side pocket, shooting with the cue ball on the head spot, it is clearly more than a 90 degree cut. (About 3 degrees more, I think.)
If you put an object ball on the head spot, and then freeze the cue ball to that ball (and have it on the headstring), and then remove the ball from the head spot, cutting the object ball into the center of the side pocket will be a 90-degree shot.
Hi Jude,Jude Rosenstock said:Actually, no. It's impossible. Part of the reason WHY it's impossible has to do with the maximum amount of rotation you can place on a cue-ball. The other is the degree of influence it will have because you're skimming the ball. A cue-ball cannot spin faster than it is shot. In otherwords, the force shown on the vertical axis cannot be greater than the force shown on the horizontal axis, at least, not when you are shooting horizontally. Imagine trying to spin a coin by simply flicking it with your finger. It's impossible unless you're holding the quarter in place when you do it.
I'll admit that what I'm about to say is theory and, as far as I know, hasn't been confirmed by tests. But it isn't atomic physics, and until proven wrong I'll believe it's right.Jude Rosenstock said:With that said, when the cue-ball contacts an object ball on a very thin cut, you get a roll-off effect. There's no force that would bring the object-ball backwards and it's so minimal that the line is almost identical to what would be achieved with zero english. The thow can only be seen in angles that are ahead of the point of contact. The more they are ahead of the point of contact, the more you can throw. This is a simple element of transfer of force.
Jal said:For reasons that are difficult to put in way that would sound intelligible (I'll try if you like), this must increase the coefficient of friction between the balls. The throw angle (tangent of) is equal to this coefficient, so the throw must increase.
The coefficient of friction can vary depending on the surface speeds. Have you ever heard of static and kinetic friction? Well, there can be two different coefficients of friction for the same materials.Boro Nut said:Whatever it is that's varying, it's not the coefficient of friction, which is a constant for any given material. Perhaps it's the speed of light.
Boro Nut
Jal said:Hi Jude,
Simple physics says that if you use a tip offset of two-fifths of the ball's radius (2/5 R), the "inside" surface speed at the equator will be zero. I'm using "inside" in the sense that for right english, the inside surface would be on the left side of the ball . The "outside" surface speed at the equator (on the right side of the ball for right english) will be twice the ball's speed. If you hit with a greater offset, say 1/2 R, the inside surface speed will be negative, or retrograde: a point on the surface at the equator will actually move backward with respect to the table's surface, or the object ball it may contact. In reality things are a little more complicated, but I think it's been verified that you can get the inside surface to move backwards (Jacksonville Project).
I'll admit that what I'm about to say is theory and, as far as I know, hasn't been confirmed by tests. But it isn't atomic physics, and until proven wrong I'll believe it's right.
It predicts that you will get more throw with cut angle (if you get the spin right) exactly because of the skimming or grazing contact. This reduces the compression impulse (average force times the duration of the contact) acting along the line between the centers of the balls. For reasons that are difficult to put in way that would sound intelligible (I'll try if you like), this must increase the coefficient of friction between the balls. The throw angle (tangent of) is equal to this coefficient, so the throw must increase.
We agree that the average compression force between the balls is less as the cut angle increases. And as a direct consequence, so is the average friction force. But because of what was just said (coefficient stuff), the friction force does not diminish quite as much as the compression force. As a result, the ball gets thrown sideways by the friction with a little more force in proportion to how much it gets propelled forward by the compression. The effect is more throw.
That's what the theory says anyway. If correct, you should be able to make the initial geometric cut at, say 86 degrees, and then throw it backward more than 4 degrees to achieve a greater than 90 degree cut. But the spin tolerances are insanely tight and it would probably be a matter of sheer luck to pull it off.
I doubt that I've convinced you since I've skimmed over a few details, but if you want to look at it closer, I'm willing. Maybe you see something I don't.
Jim