I figured this deserved another thread rather than remaining a tangent topic in another. I claimed in another thread that when I tested the extremes of the fractional aims around half-ball (5/8, 1/2, 3/8) that, when considering various speeds and spins, each of the three aims has a large range of angles and therefore shouldn't be linked to its respective theoretical angles of 22, 30, and 39 degrees. I just tested this again, and I was wrong about the low and high angles I had previously come up with, but I was very close in my assessment of how large the range is.
So, I set up a hole reinforcement donut for the object ball 5 diamonds away from a corner pocket. I marked the cloth for a ghost ball resting point directly in line through center donut to perfect center of the pocket between the points. I also marked a short line on the cloth about 4 diamonds from the pocket and along the same line to the pocket. I used two cue balls, both the Aramith Tournament that came with my Tournament set and Aramith measle ball, and placed them within 1 foot of the object ball for the lower limit test and within 6 inches for the upper limit test. Other factors that may be worth considering are that my table is in a basement, humidity was high (82%), and I haven't cleaned the balls for about 3 weeks. They aren't dirty but they aren't super shiny. My cloth is Simonis 860HR. Pockets are a tight 4.25", so that should contribute to the accuracy of the test.
I can do tests for other fractions later, but this morning I focused on half ball only. For the lower limit of angle for the half-ball aim I had the cue ball about a foot away from the object ball, and I placed it so that the mark for the ghost ball was showing as thicker than half-ball aim. I started with the cue ball resting on a theoretical 5/8-ball aim of 22 degrees and tried to make the ball using a half-ball aim. It was simple. Just a hard stun shot and the ball went easily. I repeated it. This surprised me, because I recall the last time doing this that 22 degrees was about the lower limit for a half-ball stun.
So I reduced the angle further to a theoretical 1/4-ball (14.5 degree) setup. With repeated attempts I couldn't make the half-ball shot. So I set up a shot halfway between 1/4-ball and 5/8-ball. I could make it occasionally. I found that angle, about 18 degrees, to be the low extreme for me and my equipment on a half-ball shot. For the lower limit test, all spin was done along the vertical center line of the cue ball.
I then set up theoretical higher-than-halfball shots to find the upper extreme for a halfball aim. The cue ball was placed within 6 inches of the object ball to help control aim and spin. I struck the cue ball very softly with extreme outside english, and I found the theoretical 3/8-ball angle of 39 degrees to be about the highest I could accomplish for a half-ball shot to find the short line I drew on the cloth about a diamond away towards the pocket.
The results of this test suggest that a half-ball aim has a range of:
39-18=21 degrees. I believe the other two aims will show a similar result.
If you're willing I'd love for anyone to perform this test for yourself and report your results. Maybe conditions have a huge impact on this range.
So, I set up a hole reinforcement donut for the object ball 5 diamonds away from a corner pocket. I marked the cloth for a ghost ball resting point directly in line through center donut to perfect center of the pocket between the points. I also marked a short line on the cloth about 4 diamonds from the pocket and along the same line to the pocket. I used two cue balls, both the Aramith Tournament that came with my Tournament set and Aramith measle ball, and placed them within 1 foot of the object ball for the lower limit test and within 6 inches for the upper limit test. Other factors that may be worth considering are that my table is in a basement, humidity was high (82%), and I haven't cleaned the balls for about 3 weeks. They aren't dirty but they aren't super shiny. My cloth is Simonis 860HR. Pockets are a tight 4.25", so that should contribute to the accuracy of the test.
I can do tests for other fractions later, but this morning I focused on half ball only. For the lower limit of angle for the half-ball aim I had the cue ball about a foot away from the object ball, and I placed it so that the mark for the ghost ball was showing as thicker than half-ball aim. I started with the cue ball resting on a theoretical 5/8-ball aim of 22 degrees and tried to make the ball using a half-ball aim. It was simple. Just a hard stun shot and the ball went easily. I repeated it. This surprised me, because I recall the last time doing this that 22 degrees was about the lower limit for a half-ball stun.
So I reduced the angle further to a theoretical 1/4-ball (14.5 degree) setup. With repeated attempts I couldn't make the half-ball shot. So I set up a shot halfway between 1/4-ball and 5/8-ball. I could make it occasionally. I found that angle, about 18 degrees, to be the low extreme for me and my equipment on a half-ball shot. For the lower limit test, all spin was done along the vertical center line of the cue ball.
I then set up theoretical higher-than-halfball shots to find the upper extreme for a halfball aim. The cue ball was placed within 6 inches of the object ball to help control aim and spin. I struck the cue ball very softly with extreme outside english, and I found the theoretical 3/8-ball angle of 39 degrees to be about the highest I could accomplish for a half-ball shot to find the short line I drew on the cloth about a diamond away towards the pocket.
The results of this test suggest that a half-ball aim has a range of:
39-18=21 degrees. I believe the other two aims will show a similar result.
If you're willing I'd love for anyone to perform this test for yourself and report your results. Maybe conditions have a huge impact on this range.
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