Dr. Dave's definition is:
stroke: the cue-stick and arm motion required to execute a shot.
I'll use this definition, and therefore I'll have to update my answer because I've only been considering the cue-stick.
If all different body stances, bridge hand positions, bridge lengths, elevations, grips (for example dart jump shot, pique, masse), and then different applied English and power are considered different "strokes" then the variations are infinite.
If we don't use the word stroke anymore, this is my PSR
1. I look at what I want to achieve. Usually it is always the path that I want the cue ball to travel. Secondary is the object ball (in pool or carom).
2. Then I stand there imagining the ball-fraction-tip-position combination needed. I call this my mental simulator. I stand almost perfectly still simulating over and over again the shot, depending on the complexity, up to around 5 or 6 seconds. If there is an audience watching me play then I can feel them watching my stillness and
can get subconscious and rush sometimes, but it depends.
3. I now have my solution in my head.
4. I get into position for the shot, whatever that position is.
5. I set my cue tip on the cue ball exactly where I imagined it in my head.
6. I then hit the ball by moving the cue back and forth in a straight line.
So I don't really think about different body positions or mechanics or anything like that. What is important to me is that I match reality with imagination as best as I can, and I've found this to be a powerful feedback cycle. The consequence of this is that my cueing action is perfectly straight. I can execute all types of shots the same way. The only difference I would make is that if I really want to hammer on the top spin then I would take a bigger back stroke and accelerate more "slowly" (counterintuitive) but it is accurate that way.
Also I play by feel, I don't use diamond systems or anything, doing math while playing is a distraction for me. For others it is useful.
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