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Keith
USA
242 Posts |
 Posted - 04/11/2009 : 12:56:57 AM
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I was talking with Tom during our match and I brought up the questionable safety that was previously mentioned in this forum. The shot is holding the cue near the tip and placing it under the edge of the cue ball. You then lift up causing the cue ball to move forward and hopefully allowing you to get a legal hit in close quarters. Well back to my point, Tom said that the shot would now be considered a foul. He stated that the league has defined that the cue ball must be struck in a forward motion. I was wondering if this is true or if someone is spreading this as a rumor.
Hey I was just told that we are supposed to make the balls in the pockets. That makes a big difference. |
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Torsten
USA
401 Posts |
Posted - 04/13/2009 : 11:05:53 AM
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To my knowledge, Keith, there is nothing in the rules prohibiting this shot. The only shot technique specifically outlawed that I found was the "scoop," otherwise known as the "Jonzo Jump." There are other shots ((certain masse shots come to mind)) that don't involve a forward stroke. That said, I've seen a few people attempt this shot, and while I've never thought to ask of its legality, I've always asked a third party to watch, as the technique seems to pose additional danger of fouling.
I think the worst time to have a heart attack would be during a game of charades... or during a game of fake heart attack. |
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Keith
USA
242 Posts |
Posted - 04/13/2009 : 7:50:56 PM
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Before the ruling was that it is a legal shot. The only thing I can think of is that the bca has determined that it is not legal and that is what tom was referring to.
Hey I was just told that we are supposed to make the balls in the pockets. That makes a big difference. |
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Keith
USA
242 Posts |
Posted - 04/16/2009 : 3:28:52 PM
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Phil is the shot I referred to in the original still legal?
Hey I was just told that we are supposed to make the balls in the pockets. That makes a big difference. |
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BigRigTom
USA
102 Posts |
Posted - 06/09/2009 : 6:02:28 PM
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quote:
[i]Originally posted by Keith[/i]
[br]Phil is the shot I referred to in the original still legal?
Hey I was just told that we are supposed to make the balls in the pockets. That makes a big difference.
Keith,
I saw you post to Phil and it reminded me that we had this discussion before and Phil explained it very thoroughly then...as legal in the APA....see this thread if you would like to read the whole thing.
http://www.southcoastapa.com/snitz/topic.asp?TOPIC_ID=661&SearchTerms=forward,stroke
BigRigTom
http://hardingersystems.com/BAT-Forum to discuss Billiards and Trucking or anything that interest you! |
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D-RACK
USA
321 Posts |
Posted - 06/10/2009 : 10:31:28 AM
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Define "forward". If I shoot down on the back of the cue ball and angle my cue away from the object ball, am I shooting forward?
The shot Tom mentions is legal in the APA. However, it is NOT guaranteed to produce a good hit. It is still possible to double-hit the cue ball even with this "stroke". If you think about the physics of the shot, what happens is that the tip of the cue traces an arc as it is lifted. The radius of the arc is the length of the cue (or the distance from the tip to the outer edge of the table, if the butt end of the cue is on top of the rail). Since the cue ball is a sphere, it consists of an infinite number of smaller arcs, one of which lies in the same plane as the arc formed by the tip of the cue. In order for the cue ball to move at all, the two arcs must intersect (tangent isn't good enough, that will produce no movement of the cue ball). And as anyone who understands geometry knows, two coplanar circles that intersect must do so in exactly two points. It takes a finite amount of time for the tip to travel from the first point of intersection to the second, during which time it is passing through the space previously occupied by the cue ball. It is possible for the cue ball to return to that space before the tip has passed through the second point of intersection, in which case the result is a double hit.
The physics of this shot are actually the same as the physics of shooting down on the cue ball to avoid a double hit. When shooting down, your tip also traces an arc. If your stroke is straight, the radius of the arc is infinite. Nevertheless, there is still a finite amount of time during which the cue occupies the space where the cue ball was. The difference is that in the first case, the cue leaves the space without changing direction, so it spends less time within that space and the likelihood of a double hit is reduced. Not eliminated, reduced.
Why such a technical explanation? Because the first post mentions Bob Jewett. Bob is a physicist by trade and would appreciate the details of the physics involved, and you should too. Bob and I have actually had numerous electronic conversations in the past about such things, including the physics of a "swerve stroke".
Now, why does APA consider this shot legal? Because it falls into the category of "too technical to legislate". What if I did essentially the same thing, only I kept my bridge hand under the cue and held the back end with the other hand? I could produce the same cue motion from this starting position. Would you be able to tell if the motion was "forward"? What if I was holding the cue with the tip above the edge of the cue ball, and accidentally let the tip drop? This is the same tip motion, only in the opposite direction. If it produced a good hit, would it be a foul? What if it wasn't accidental? Would you be able to tell? These are legitimate questions that are difficult to answer if you try to legislate the stroke. The APA feels that the best thing for our players is to avoid all of these issues with a simpler set of rules. If you contact the cue ball with your cue, it makes contact with a legal object ball, and something hits a rail or goes into a pocket, it's good - no need to concern yourself with how the initial contact was made.
By the way, this isn't the only clever way to avoid a double hit. I can do it with a HARD, FORWARD stroke that is (1)parallel to the table, and (2)parallel to the line connecting the center of the cue ball with the center of the object ball. If you want to know how, ask Kato Lin. (HINT: It has something to do with the coefficient of friction)
Phil
THERE!
GO FOR IT!!!
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? about a safety
