Direction of play questions gain tremendously when presented that way - with slightly different positions leading to different directions.
I'm sure you're right, but there is possibly a more fundamental point to get right first. I translated the
Direction of Play book, and so I have naturally followed its progress a little. I have noted that the concept has become one of the most popular among western players. It seems to me far more popular than its equivalent in Japanese books, and much more so than in Korean or Chinese books.
It is in fact something of a western construct. The Japanese refers to the direction of the stones. That's rather a different focus. I chose direction of play rather than stones as the result of a discussion with Stuart Dowsey, but our preference was frankly based more on what sounded right to the English ear than on what was accurate but clumsy. I have often wondered since then whether it was a mistaken approach. I think the actual text of the book makes it clear that the directionality of the existing stones on the board is the main factor, but (a) that might be a wrong assumption, and (b) it doesn't apply to those who hear and think they grasp the concept of direction of play but haven't read the book.
Maybe it's splitting hairs, but I think it might just be worth harping on about the directionality of stones rather than the direction of play. One of the problems with fuseki analysis is that there are many guidelines floating around untethered. Balance between fourth and third lines, approach on the widest side, access to the centre, keep the opponent separated, direction of play, etc, etc. Each one is easy enough to understand in itself, but the difficulty lies in creating some sort of hierarchy - to establish which guideline to use in preference to another when they both seem possible. My impression of Kajiwara's book was that he meant to establish part of this hierarchy by shifting focus away from the next move back to the previous moves. You analyse the directionality of the existing stones, and if they have any you act on it as a top priority. Only if there is no strong directionality do you then look elsewhere for guidelines such as "approach on the wider side". Of course, Kajiwara was too dogmatic for the taste of many, but surely the idea of establishing a hierarchy is a valuable one.
Using this idea of hierarchy with the concept of "disruption", or alternatively establishing a presence in many parts of the board, if I had a pupil who was talking about this sort of play, I'd want to be sure that he was first applying even more basic principles such as a maximum of five groups or a maximum of one weak group, or if he was claiming to keep the opponent separated, was he actually separating weak groups.
There are also macro principles at an even higher level, and I'd want to see evidence that these were understood, too. For example, there may seem to be little difference between invading his territory rather than defending your own, so that you both end up with small territories instead of both with large ones (especially to those of a mathematical bent who routinely give weight to thought process such as 61-60 is no different from 11-10). However, at what I'd regard as a higher level of thought, there are consierations of, say, risk. There may be an unacceptable risk in going first and giving your hand away in a more open and unpredictable position. Going first by invading/disrupting and settling the position (and of course ending in gote if all goes normally) may well give the opponent a big advantage now that the smoke and much of the unpredictability have cleared. (You can, of course, go up yet another level and say it all depends on time limits, but the principle is the same.)
All rules can be ignored, but it does seem wise to at least try them out first, and in a hierarchical order, in exactly the same way as physicians seem to worj when presented with an array of symptoms or doing triage.
To summarise, I am positing (not with huge confidence, though) that directionality of stones (analysis of existing positions) belongs on a higher level than what is usually understood by direction of play (development of future play), and so must come first. Further (harking back to my previous post), it would be ideal if all this happened in the right order as the result of forming good habits.
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