Badsnookerplayer wrote:I have never considered something that you have mentioned here and it probably seems blindingly obvious but when you play plain ball, to what degree does the cue ball 'slide' rather than roll? I have always assumed that it is just rolling forwards
I am sure that you already know that there is no answer to that question, or if you prefer, the answer is infinity. The number of variables from tip position on the cue ball to the strength at which the shot is played makes the answer utterly incalculable. With the absolute plain unadorned balls of Snooker, one really can't "see" what is happening at all, and can only play shots by "feel" and "intuition" and "experience". There is little or no visual feedback at all about the actual motions of the balls, cue or otherwise and you can only try to judge what they are doing spin-wise based on how they react.
We mostly think of the Game of Snooker as being two dimensional as if drawing lines on a piece of paper, but it is really much more of a three dimensional game than even most good players realize. That is why there is a plethora of "training" cue balls to give visual feedback for our brains to learn from experience. Here is a good video to demonstrate (YouTuber Tequila is an absolute genius for editing video Snooker related).
https://www.youtube.com/watch?v=mQ_7FzNTOz8In particular the stroke at about 2:05 (drag shot) and the stroke at about 3:00 exactly demonstrate action that people seem to have a hard time grasping in their mind without this visual feedback.
The way you see the balls bouncing around in the video is another common cause of kicks in my own opinion. In real time, we think the balls are rolling or sliding so we believe the points of contact are on the equator of both balls, but I believe the cue ball spends more time bouncing than we realize (another reason why screw shots tend to not kick....the cue ball is held down on the cloth by the reverse spin).