M Dugger,
Basically, you are saying that choices and variety of shot types contributes to shot values. I agree.
Dr. Hurdzan shows, in his book, a chart from Stanley Thompson, showing the variety of approach shot lengths, in graph form. It may be that this is the chart zwal refers to from his class. Presumablly, Thompson would use it as a test during routing to better ensure the old "using every club in the bag bromide" was met. But, shot value is more than a variety of distances on the approach shot.
So frankly, Thompson did some nice work, but his view, at least as reflected in that chart was fairly simplistic - make them hit different length approach shots, and hopefully, vary it, from short to long, rather than a series of long shots, for example.
Hurdzan goes on to say that at least part of shot value also lies in the required precision to be successful. For approach shots, he starts with the USGA Slope Rating Chart for green sizes. As a review, I'll say that it considers a "normal green" size to be 14% of the approach shot length in width, and 21% of approach shot length in length for 20 handicappers. For scratch players, its about 14% both ways. BTW, for Dave Pelz fans, this also correlates with his research nicely.
As a shamelessly rounded example, then, if the rating committee anticipated a 200 yard approach shot from a 20 handicapper the "average challenge" green, which they define as one that 2 out of every 3 20 handicap golfers will hit, the green "should be" 28 X 42 yards, (84 X 126 feet) more or less, a 150 yarder 21 X 36 yards, and a 100 yarder, 14 X 21 yards.
But, as Mike points out, if every green was sized according to this formula, then each approach shot, regardless of length, would have exactly the same shot value, at least in terms of precision required. If you had two effectively equal length holes (after accounting for wind, slope, etc.) then a variety of shot values would be better created by having one with a smaller green, and one with a larger green, no?
But shot value is more than the precision requirements, too.
As you suggest, shot options, shot pattern variety, hole type variety, wind direction and differing wind challenge, hazard difficulty, etc. all contribute to shot value in some vague and hard to define way.
Using 16 at Cyrpress, or 17 at TPC as examples, so does natural beauty, phycological difficulty and round position! Those hole may affect shots on the front nine!
Of course, modern golfers would always add fair as a component of shot values, whatever that means! In their view, the smaller than average green on a long approach is probably "poor shot value" but I don't think one or two of those per round to test iron play is such a bad idea.
Just my .02
