What is good stroke objective?? Is to deliver the cue not the cb to the correct approach angle and line of aim and correct contact tip at cb , what happens fraction of a second after that do not matter. If one does not prep his warm up stroke correctly and get muscels used to the shot ( storing in memory direction of stroke for each shot), he or she will have hard time making balls.
Everybody has made so many good points and talk about very important aspects of delivering a "precise" hit of the CB with the tip of the cue. It's the precision and speed of the hit to the CB that creates the spin. Everything else is in support of this precise hit. So I agree with Naji All the practice we do is to discover our optimum with the traits we bring to the table. Without good mechanics we cannot obtain the optimum or control the amount of spin desired for a particular shot.
Anyway, that's my $.02.
Al