[bambam]

Building a "strong, powerful, repeating golf swing" is like building a custom home. It starts with a sturdy, level foundation and floor (steady head). You'll also need strong, plumb walls (balance}, and a roof with good pitch (rhythm). The imperatives are the siding, roofing, windows and doors. You must have them, but you can choose them (components). Add some beautiful landscaping (extensor action) for curb appeal and you'll end a golfing machine.

Interesting analogy, Rick. This is sort of how I've always viewed those 6 items. I've always seen the essentials as the 3 key things needed, at least to some degree, to make the athletic motion required to efficiently hit a golf ball with a club. The imperatives, in my view, are the elements that introduce precision to that motion.