The ultimate goal of a pool stroke is to move the cuestick forward in a straight lineThe SPF guidelines ensure that the end result is exactly that.
Thus, you can clearly evaluate a students stroke against the SPF instruction method WITHOUT even striking a cue ball.
You can achieve the same results through other methods, but SPF is the easiest way to consistently move the cue properly.
Again, this is the marketing. "Bigger," "better," "stronger," "faster," "easier," etc, are all marketing words. Again, I am not detracting from the actual success of SPF instruction, rather I am simply pointing out that it is only a tool to achieve the goal - which you have accurately identified as moving a pool cue.
You must do two things to make the shot...aim at the right place, and be able to deliver the cue ball where you are aiming. SPF address only the delivery aspect. There are other parts of the class where we address aiming.
Fair point on the other instruction received.
However, I was primarily addressing Randy's point that SPF is a grading system and not learning system. Clearly the SPF school is more robust than a simple grading system. As for the delivery aspect, the SPF system is really targeted to the mechanics of moving the cue stick through a particular range of motion, which is then INTENDED to provided a desired result, i.e., cue ball movement.
Most good players, whether they know it or not, have most likely already incorporated some form of SPF into their stroke. We just bring those aspects to the forefront, so when there is a breakdown, it is very easy to identify and correct the problem.
This necessarily implies that every player must be (re-)taught the SPF system in order to be graded against it. The marketing lies in the fact that knowing and understanding the SPF movements will result in improved pool playing. While this may be true, it is once removed from the actual result of being able to tell if you are moving the cue stick along the SPF taught specific motions (i.e., the grading benchmark).
Just to reiterate, I am confident that SPF does work for some players. Some people actually benefit from the tools enabling diagnosis of stroke mechanics. And without a baseline (i.e., benchmark stroke) this may not be possible. However, to say that achieving the benchmark stroke will result in better play is as much hyperbole as fact.
-td