Some time ago, I witnessed (and even participated in) a discussion on RGG about the seemingly inability of the professional Go players to explain certain principles and ideas. An example was given of the term "natural flow" and how it applies to the game. This term can be encountered in many a pro commentary to many a game, but its usually vague and undefined. When confronted directly with a question about "natural flow", a pro either gave no explanation at all or only something as cryptic as to be highly unsatisfactory to the questioner.
An idea was put forth that the pros either don't understand themselves what they are talking about or there is some kind of pro conspiracy which prevents them from giving satisfactory explanations to amateurs. I find both these notions ridiculous, to be honest, but had to admit I did not have any better explanation, other than maybe a simple "you are not ready" or zen-like "if you have to ask you would not understand the answer". Bah!
Well, I do not really have an answer now either, but ever since the discussion I could not shake a slight uneasiness and had to think about "natural flow". On and off. And this is the essey in which I would like to share my thoughts.
I think that the best way to wrap a mind around the idea is to dissiminate it. In our case, we have to dissiminate the term "natural flow" itself. It consists of two words: natural and flow. By now you are probably thinking that I have no clue what I am talking about. Well, I do! Well... not really. But lets continue anyways. Do-oh! :)
The easier of the two words is, by far, the word "flow". What does it mean? Well, Encarta gives its first definition as "move freely from place to place", Merriam Webster says its "to issue or move in a stream", while according to The American Heritage Dictionary, it means "to tove or run smoothly with unbroken continuity, as in the manner characteristic of a fluid". Other references give other diefinitions, but all of them have some element of "movement from place to place", usually with the addition of the word "freely", "smoothly" or something similar.
But there is even more to that. The term "flow" also implies parts (like water molecules, or grains of sand... or Go stones) to move in such manner that one follows another, as opposed to each one going its own merry way. Its easy to imagine it as a string of pearls moving in a line on a smooth surface of a table. Of course, with water and other fuids it does not quite work this way, but the approximation is close enough for our purposes. At least, we can say with certainty, that where "flow" is concerned the resulting movement of the whole is progressive rather than random. The stream flows downhill, and any volume of water molecules within this stream will eventually find its way to the bottom.
Now, what does that mean in terms of Go?
Well, since Go is a static game (i.e. the pieces do not move once placed), movement from place to place would indicate a sequence of moves which takes the game from one position to another. Pretty straight-forward, ain't it? The word "freely" would indicate that the moves were not part of a forced sequence, but rather made with a freedom of multiple choice among other moves of equivalent quality. Like it is often seen in fuseki when there may be many sequences producing positions of seemingly equivalent values. And the emphasis is here not on some theoretically perfect equivalence (which we often cannot determine), but only on our inability to definitively evaluate the differences between the resulting games.
.....
A counter-example would be a semeai in which there is only one sequence of moves which gives optimal result - and this sequence can be calculated and determined. There is no "freedom" in folowing such sequences since any deviation would lead to a loss. Now, one could argue that a loss is also a possible outcome which you are "free" to chose, but this would degrade this discussion to meaningless obscurity. So I "freely choose" to refrain from that. :)
Actually, any example of forced move or a sequence of moves could not be considered to be following a "flow". At least, if we agree with the above considerations.
So, summarizing, i would say that in Go, a flow denotes a "sequence of moves which is not strictly forced" but in which "the moves are slightly induced by each other".
Now that we have dealt with the issue of the word "flow", let us turn our attention to the more difficult task of defining the word "natural". As before, we start by consulting some resources. Natural, natural... what does it mean? Well, in most cases the first meaning of the word is something like "of nature" or "derived from nature". This does not really seem to be the meaning we are after, so lets dig deeper.
Among other meanings of the word "natural" we can find ones more relevant to this issue, such as "normal", "ordinary", or "to be expected". Some sources give "relaxed and unaffected", while others include "arising easily or spontaneously" or "happening in the ordinary or usual course of things". I could go on, but I think this is enough for the moment. I hope you are guessing where I am going with all that.
If not, let me just spell it out. The meaning of "normal" which is pertinent to this discussion, is also highly "subjective". For what is "normal"? What is "ordinary"? We all sort-of know what it is, but we also know it each in our own separate ways. What's "normal" to me, might not be "normal" to you, and so on...
And yet, there must be some common backbone to even such subjective terms, or we would not be able to function as a society. We would all agree, for example, that it is "natural" for water to flow downhill. And confronted with the above statement, we would all probably agree that the usage of the word "natural" was appropriate in the above sentence. What's more, we can agree on that even if we also know that there are environments in which water does not necessarily flow downwards, in space for example. And yet, physically speaking, it is as "natural" for water to flow donwhill on earth as it is "natural" for it to form blobs and float around in space. Still, the later behavior we would not necessarily consider "natural", would we? Well, maybe...
But there is still more! We can agree that it is "natural" for water to flow downhill on earth even if we do not really understand "why" it does so. I know, I know, gravity and all... but what is gravity? Do we know? Can we ever know? Anything? To the last bit?
Or does this topic just turned even more philosophical than I intended?
So we would agree that it is "natural" to be upset when ones wallet has been lost, as much as it is "natural" to be thankful to the person who found and returned it. It is "normal", no one raises an eyebraw at this. It is "natural" to grieve a loss, and it is "natural" to enjoy a gain. We do not necessarily know "why" we feel this way or that, but we do and that's that.
The point is here that if we try to dissect every single concept we run across to its least and smallest component, we will spend eternity looking for ways to cut electrons and quarks. Some people do, bot for the rest of us - this way lies madness. We have to draw a line somewhere and agree on some common axioms on which we can build.
So lets just assume that we all know pretty much what is the meaning of "natural" in the sense of normal, usual, ordinary, unforced, and so on.
Now, all that's left, is to put them two words together and see what comes out. :)
As we decided before, "flow" denotes a "unforced sequence of moved", and "natural" denotes something that is "normal", "relaxed", and "unaffected".