I’m reviving this thread because it’s related to recent topics. The developments with Earl then Shane adding length and mass to their cues started discussions. The added mass behind the hand was speculated as allowing players to pull the cue through the ball rather than push through. After studying top pros and coaches some seemingly unrelated observations suddenly came together and made sense.
The mass discussion reminded me of Ronnie O’Sullivan commenting that he brings the mass of the cueing arm through the ball. Elementary physics with Newton’s second law tells that F=ma. Physics also tells us that energy is conserved during collisions. So F=ma also applies to the cue ball and ball to ball collisions. In simple terms if a large mass hits a smaller one the small mass will end up going faster than the larger mass was at impact. A heavier cue with the same speed swing will send the cue ball farther.
Suddenly the different stroke methods commonly used historically took on significance. In the interest of brevity, mass was central to each evolution. Initially using a fingertip grip the mass was limited to the cue. The pendulum stroke added the forearm mass to the force formula. Lastly when force variables were wanted players added the mass of the entire cueing arm. By adding the extra mass the acceleration component could be slowed and still impart the same force. So even on a soft follow shot the big muscles can slowly drive a ball to the rail and off. Lesser mass with more speed to provide the same force has to be careful the extra speed does hit too hard and that fear might cause the player to quit on the shot. The slower speed, extra mass shot is more measured and controlled.
I’m not advocating for a method here, just describing. Each shot has different needs and good players have different ammunition in their arsenals. One principle has remained constant and that is the idea of using a relatively level cue through impact. Del Hill, an elite snooker coach, suggests that the level cue idea has been taken too far and while through contact and beyond it is ideal, during address its bs, in his words. When looked at in his context the large number of premier players who address the ball on a downwards slope near the base of the ball and many who use what has been described as a pump handle stroke, offered context.
The basic modern snooker stroke involves player aiming the shot directly down the cue, when aligned the chin and side of the chest move to prevent sideways deviation or a lifting of the cue. Using a pendulum stroke with that setup results in the hand stopping abruptly against the chest. Del describes the action as looking like a chicken pecking. His instruction is that the address position needs to slope at address so the cueing hand can clear the rail and have some tolerance. With stop action and a protractor I measured a Ronnie draw shot on a side blue at about a 10° slope. His backswing, arcing up, caused some of it. His bridge was about 10 inches and tip came back to under 2 inches from the vee. The arm angle was vertical at address with the upper arm angle at ~75° opening changing to ~105° at the back. His hand was about 8-9" off the table. The point is that even the pendulum stroke arcs up and creates a downwards cueing angle at the back. The pendulum stroke is relevant since the pump handle players use its backswing. If the cue travels back along the side of the body, it is positioned on the target line before going forward. Good players who want a simple stop or stun shot not highly sensitive to speed will simply pendulum back and with a limited follow through never hit the body. They still accelerate through the ball driving it. The difference comes when they bring the entire arm into play.
While they may use a pendulum backstroke to assure alignment at the back, they now hold the angle at the elbow and initiate the forward swing by moving the arm in a one piece motion down. The downward force will start to close the elbow hinge and the cue starts an arced path much like a plane landing. Both when reaching the horizontal continue forwards. Rather than the finish ending with the hand in the rib cage, the drop flattens the cue path and allows the hand to finish under the chest still on line.
Sorry for the length. Just wanted to share with others on this journey.