Yes, and then it has to rise and then drop again during the forward stroke.
But to be clear, the “full arm movement” I spoke of is neither a pendulum or piston stroke.
pj
chgo
I agree. The model starts with a downward plane at address. From that address position, the cue is arced back like the first half of the pendulum stroke, fulfilling the snooker 4 point contact model. In theory the cue has now been drawn back in a straight line with the bridge and side of the chest constraining sideways movement. At the back, the cue plane is more elevated than is normal for a standard pendulum stroke. In theory the cue is vertically aligned with the shot line. In other words it is still lined up before moving forward. This is where the elbow starts down flattening the plane. While the elbow may lower slightly the entire arm is simply set in motion by the move.
A natural toss motion while standing uses the same dynamic. On the final back motion, in a toss, the elbow angle opens. Once the forward toss motion is initiated, the elbow remains open while the whole arm initiates the forward movement. The elbow now becomes part of a dynamic motion sensing the internally calibrated action needed to gauge velocity and trajectory, st the elbow closes.
You are absolutely correct, the whole arm stroke is neither a pendulum nor a piston stroke. Arm alignment is crucial to the stroke. That said once aligned it is harder to throw off line and allows a slower velocity to achieve the same momentum. From a motor skill perspective it should theoretically reduce errors.
The advocacy for a pendulum stroke is theoretical in nature as well. It starts with a level cue at address, and a vertical forearm at contact. The objective is a simple engine taking the cue through a level plane at contact. While it makes a good teaching model for neophytes, more advanced players need to realize that theory often doesn’t translate into practice. It’s a good first step, but it’s only AN ANALOGY. It’s like believing that a map is the actual road. A conceptual model is just a guide. When reality differs it can be a round hole/square peg scenario when context doesn’t match the analogy. Stick to the analogy when it it’s useful but be willing let it go when it’s not.