The Half-Ball Hit -- part 1

A description of some important features of the half-ball hit at pool

Category:

Sports

Tags:

• billiards
• instruction
• aiming
• half-ball
• pool

[mtb2004uk]

This is a good video and has a lot of great points but has a technical deficiency. A cue ball striking an object ball half-ball with normal roll actually deflects approximately 40 degrees.

You can find this by refering to the graph shown in the book "The Science of Pocket Billiards" which was written by an engineer.

[FargoBilliards]

Jack Koehler's "The Science of Pocket Billiards" Figure 5.5 (page 57) has the cueball deflection angle maxing out at about 38 degrees for a cut that is a little less than half-ball. You have to read his small print. He's not talking about the final PATH of the cueball. Rather he's talking about an effective angle after 24" of cueball travel that incorporates the early curve of the cueball off the tangent line. If he hit a little harder, he'd have a whole new graph.

[fogertzernam]

@mtb2004uk schooled.



[edoson01]

I think you have a little mistake in the vid, or at least some inclearity.. When you show examples of the half ball hit you draw a line from the center of the cue ball to the center of the object ball. If i understood right the first part of the vid, the line should go from the center of the cue ball to the edge of the object ball to indicate correctly the desired path of the cue call. Am I wrong here?

[MrKoreanmovielover]

who knows other books related specifically or to more precise, mathematically to pool and snooker. hope you can help! anyboydy? cheerz!

[rob3c]

Natural Roll and Reverse Natural Roll are NOT symmetrical situations with respect to the tangent line (think about the vector orientations). If you put true RNR draw on the CB, you will overdraw the 90 degree reference by about 18 degrees - a significant margin. You're thinking of a draw/speed ratio of -0.625 instead of -1.0. This is an especially critical difference when the CB and OB are close together (2ft or less apart, depending on table friction).

[GetMeThere1]

This is really great. For me personally, you would be the IDEAL teacher--your analytical approach to things is just like mine (and, I suspect, a fair proportion of those who like to play pool enough to consider learning more from an instructor).

[rhmsr63]

well said and good video. more power buddy.

[mtb2004uk]

However, between full ball and three-quarter ball alot happens with the track lines, you need something in the middle of that to have something to reference and you need a half way mark to study. Exactly the same arguement can apply even more so from what would be 'zero' ball to quarter ball because a. zero ball doesn't exist and b. alot happens during that range too.

[mtb2004uk]

Yeah ok, I now see what your meaning but never had the protractor out to check it. Infact your video is very good video in this way because it shows you the value of knowing particular cut angles. People should study different cuts for the 1/8 1/4 1/2 3/4 7/8 noting the you add an 1/8 towards the extremities because nothing really happens much different between 1/4,1/2 and 3/4 and just knowing just those 3 angles around these track lines is enough to be very precise.