CreeDo said:
....Based on the high speed videos he's posted and physics stuff:
Low+outside will let you hit the ball fatter and get best results if you want to minimize sideways drift, but there's a limit to how far away you can be for this to work. I think he estimated about 6 ball widths only. I thought that might be a little conservative, but maybe all the times I've tried hitting low outside on shots like this, I'm deluding myself into thinking there was less drift when in reality it's the same drift as I woulda gotten anyway.
Yes, I have a program that calculates this stuff, and it agrees with what you're saying. I don't think Dr. Dave is being conservative. This technique of using outside or inside english and throw to significantly manipulate the sideways drift (tangent line) velocity becomes fairly significant only when the balls are pretty close together, a matter of inches, more or less.
But with enough cue elevation, you can also masse/swerve into the OB and make a much larger difference in the effective cut angle. In the case of both Joey's and Aaron's shots, using inside while jacked up would be the choice, if you wanted or needed to use english at all. But figuring out on paper the optimum amount of sidespin versus pure draw would take quite a bit of work. I'm not sure it's worth it as it will be different for almost every shot. There are numerous variables, including just how much you want the CB to draw back.
CreeDo said:
Low inside is apprently no go (I was curious about this especially), and will probably increase drift as you're forced to cut a little thinner to compensate for throw.
I've practiced using inside to exploit the increased angle it allows in order to increase drift velocity, for maybe hours. All the while I thought it was adding significantly to it, until I looked at the physics (and probably was prompted by statements from Ron Shepard). As indicated, the balls have to be very chummy with each other for any really significant effect to take place. You don't gain anywhere near the apparent increase in cut angle, just the increased approach or "ghost ball" angle as Dr. Dave has called it (measured with respect to the line of centers of the balls in their pre-shot positions).
CreeDo said:
So the answer seems to be straight draw. I think this makes sense for 2 reasons... 1. Your low outside can't be useful over such a long distance anyway and 2. I think when you combine side with draw, you may be 'polluting' the draw a little by not hitting the CB as squarely. There's still draw but the effect is not as strong as when you hit center draw, moving the tip to the side for your spin also forces you to move it up a touch to avoid getting too close to the bottom left 'edge' of the ball. If you know what I mean. And moving it up has to hurt the draw a little.
For Joey's shot, I think you're probably right. If you hit it slow enough with inside so that swerve/masse lends a helping hand, you're also going to necessarily lose more draw spin on the way to the OB. Swerve takes away spin (both draw and sidespin) while doing its job. But without a lot of math or time at the table, I'm not exactly sure that there might not be an optimum amount of inside for some moderate cue elevation, other than zero.
CreeDo said:
Interestingly Dr_Dave found that for long distances, draw strokes closer to the center (a little bit) held their spin and got better results than the kind of pure low hits you'd use for closer shots.
Yes, that's true if you have limits to the amount of cue speed you can generate relative to the distance between the balls. That is, if any speed was possible, hitting lower right up to the miscue limit would get you more draw, no matter how far they were apart. But how many of us can produce it when the balls are six feet from each other?
I think another possibly more important conclusion of his is that moving out to the miscue limit is unnecessarily risky for most shots. The law of diminishing returns takes over, giving you very little extra spin for the gamble involved. I think Ron Shepard or Bob Jewett has made this point before.
Jim
Don't be shy. I would like to see everyone put their own answer on the line.
). Just by looking at the diagram, I want to say that I'd hit it with center draw (and a lot of it), but I might feel differently when I'm actually looking at the shot in person.