Announcement

Collapse
No announcement yet.

Estimating No-Throw "Gearing" Sidespin

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Estimating No-Throw "Gearing" Sidespin

    [WARNING: SCIENCE AHEAD - TURN BACK NOW!]

    Most of us know that hitting a cut shot with outside sidespin can eliminate ball/ball friction and the resulting contact throw, if the amount of sidespin is just right for that cut angle. But if we apply too little or too much sidespin, then throw isn't fully eliminated (and may be increased or even reversed).

    Is there a simple way to know in advance how much sidespin is the right amount to just eliminate contact throw? Here's a simple method that I dreamed up, using the fractional CB/OB overlap for the cut angle you're shooting and the fraction of maximum sidespin you're applying. The general rule is:

    "Gearing" (no throw) sidespin = the fraction of maximum sidespin that, when added to the CB/OB overlap fraction, totals 1.

    In other words,

    - 3/4 ball hit: 1/4 maximum sidespin*
    - 1/2 ball hit: 1/2 maximum sidespin*
    - 1/4 ball hit: 3/4 maximum sidespin*

    Note 1: Of course the amount of sidespin you want usually depends on where you want the CB to go, so usually this technique can only tell you how close your desired sidespin is to the no-throw amount.

    Note 2: Maximum sidespin = 1/2 distance from CB center to edge.

    Hope it helps somebody (or is at least interesting),

    pj
    chgo

    *For you geometry geeks (I know you're out there ): the precise sidespin fraction is 80% of the above amounts, but that's too much math for a rule of thumb (especially one based on imprecise estimated cut angle fractions).
    Last edited by Patrick Johnson; 10-04-2017, 03:31 PM.

  • #2
    thanks for sharing Patrick

    Comment


    • #3
      Originally posted by lll View Post
      thanks for sharing Patrick
      As my friend Dr. Dave says, I aim to sqwerve.

      pj - squirve?
      chgo

      Comment


      • #4
        Originally posted by Patrick Johnson View Post
        [WARNING: SCIENCE AHEAD - TURN BACK NOW!]

        the precise sidespin fraction is 80% of the above amounts, but that's too much math for a rule of thumb
        Oh, thanks for the correction... no wonder I've been having trouble... I've been using 78.5%.

        (Interesting stuff, for real. Thanks.)

        Comment


        • #5
          Originally posted by Patrick Johnson View Post
          [WARNING: SCIENCE AHEAD - TURN BACK NOW!]

          Most of us know that hitting a cut shot with outside sidespin can eliminate ball/ball friction and the resulting contact throw, if the amount of sidespin is just right for that cut angle. But if we apply too little or too much sidespin, then throw isn't fully eliminated (and may be increased or even reversed).

          Is there a simple way to know in advance how much sidespin is the right amount to just eliminate contact throw? Here's a simple method that I dreamed up, using the fractional CB/OB overlap for the cut angle you're shooting and the fraction of maximum sidespin you're applying. The general rule is:

          "Gearing" (no throw) sidespin = the fraction of maximum sidespin that, when added to the CB/OB overlap fraction, totals 1.

          In other words,

          - 3/4 ball hit: 1/4 maximum sidespin*
          - 1/2 ball hit: 1/2 maximum sidespin*
          - 1/4 ball hit: 3/4 maximum sidespin*

          Note 1: Of course the amount of sidespin you want usually depends on where you want the CB to go, so usually this technique can only tell you how close your desired sidespin is to the no-throw amount.

          Note 2: Maximum sidespin = 1/2 distance from CB center to edge.

          Hope it helps somebody (or is at least interesting),

          pj
          chgo

          *For you geometry geeks (I know you're out there ): the precise sidespin fraction is 80% of the above amounts, but that's too much math for a rule of thumb (especially one based on imprecise estimated cut angle fractions).
          i find this fascinating, but ive spent the last 10 years of my pool life trying to eliminate english and spin from my game, sometimes its just not possible of course, but i try to play pool these days with a minimum of english and cb movement......even in 9 ball......

          Comment


          • #6
            Originally posted by poolisboring View Post
            i find this fascinating, but ive spent the last 10 years of my pool life trying to eliminate english and spin from my game, sometimes its just not possible of course, but i try to play pool these days with a minimum of english and cb movement......even in 9 ball......
            Great Idea.
            Rod.

            Rodney Stephens.
            (e-mail) rod.stephens0105@att.net(e-mail) #713-973-0503 is now working

            Comment


            • #7
              Originally posted by LSJohn View Post
              Oh, thanks for the correction... no wonder I've been having trouble... I've been using 78.5%.

              (Interesting stuff, for real. Thanks.)
              lol

              In case you have a masochistic level of curiosity, here's Dr. Dave's (much more detailed) info on the topic: http://billiards.colostate.edu/threa...h.html#outside

              pj
              chgo

              Comment


              • #8
                Originally posted by poolisboring View Post
                ive spent the last 10 years of my pool life trying to eliminate english and spin from my game
                Me too, but maybe not as ruthlessly as you have. For me, cue ball control is the "art" of the game, so I want to be good with spin (and it's fun ).

                pj
                chgo

                Comment


                • #9
                  Math? That mean I have to think? Any pictures? I always thought that if you wanted no spin, you would use center. I marvel at opponents who use center most of the time. What determination. If I ever get my table set up I may look at the math again. I have one of Joe Porper's aiming technic books. Lots of math and diagrams. When I play, either I am on or I am off and I could not tell anyone how I aim except to tell them to find the center of the object ball. My problem is finding that spot. If I can see it, then the cue ball is directed to that spot using high, low, left, right. Math? Have you got something for arm speed, a gadget that keeps my head down?
                  I feel pool is way off for me. I am thinking of getting a room next to a local room in Kentucky, or Philly, Sacramento, maybe Chicago if the Cubs get to the World Series to play someone cheap for ten days.
                  Last edited by Scrzbill; 10-05-2017, 04:04 PM. Reason: Puncuation
                  Coyotes, Eagles, and Deer, oh my!

                  Comment


                  • #10
                    Originally posted by Scrzbill View Post
                    Math? That mean I have to think. Any pictures?
                    Sure, there are pictures. Here's one from Dr. Dave's website that illustrates the more complicated (and more precise) version on which my simplified technique is based.

                    pj
                    chgo

                    [ATTACH]63104[/ATTACH]
                    Attached Files

                    Comment


                    • #11
                      ...and here's one of mine showing the same technique for "gearing" English when kicking (to "true" the rebound angle).

                      This illustration shows that the same principle works for eliminating ball/cloth friction when kicking, so the CB rebounds at close to a true equal angle (assuming no follow or draw spin). Imagine that the rail is actually an OB that you're cutting at a 45 degree angle (the line perpendicular to the rail is equivalent to the cut angle). A 45 degree cut is about a 1/4 CB/OB overlap, so my simplified technique tells us to use 3/4 of maximum sidespin for gearing outside sidespin (you can see that's where the tip is contacting the CB), so the CB "rolls naturally" along the rail.

                      pj
                      chgo

                      P.S. The same principle also produces instant "natural roll" along the table surface when hitting with follow. Imagine the surface is an OB that you're "cutting" straight down toward the floor - that would be zero CB/OB overlap, so you apply full maximum follow: zero plus 1 = 1 (or to be exact, 80% of full follow).

                      [ATTACH]63490[/ATTACH]
                      Attached Files
                      Last edited by Patrick Johnson; 10-05-2017, 04:49 PM.

                      Comment


                      • #12
                        Originally posted by poolisboring View Post
                        i find this fascinating, but ive spent the last 10 years of my pool life trying to eliminate english and spin from my game, sometimes its just not possible of course, but i try to play pool these days with a minimum of english and cb movement......even in 9 ball......
                        While I admire that, I can't imagine playing 1p without loads of English.

                        Comment


                        • #13
                          Originally posted by straightback View Post
                          While I admire that, I can't imagine playing 1p without loads of English.
                          same for me, thats why i stink at one pocket......

                          Comment

                          Working...
                          X