John F. There is a recent book Atsuku Utsu. T. Mark Hall and I gave a day-long British Go Association seminar recently on this book. To make it make sense in English I coined the terms MI-thickness, SA-thickness and ER-thickness (otherwise you end up with sentences like 'thickness is part of thickness'). For the seminar, rather than attempt my own definitions, I collected and translated all statements from this and several other thickness books relating to each type of thickness. Obviously we discussed and explained everything in detail, but as a taster here is part of the list of statements ny pros for sa-thickness (atsusa). The way we used this on the day was to put people in groups with the task specified (and similarly for MI- and ER-).
Using the following examples of references to sa-thickness as a guide, try to come up with a comprehensive definition that would account for as many attributes as possible:
1 Mi-thickness is part of sa-thickness.
2 Sa-thickness games are not only examples of how to use mi-thickness but they also include examples of various kinds of style-thickness (atsui uchikata).
3. Sa-thickness allows the opponent absolutely nothing.
4 Use sa-thickness for reduction.
5 You will therefore turn mi-thickness into sa-thickness (atsusa) and bring about a "thick game" (atsui go).
6 The various extra profits associated with sa-thickness will manifest themselves ultimately as profitable "thick prospects".
7 The features of sa-thickness vary according to the opening, middle game and endgame. But basically what lies behind it is a "thick style" (atsui uchikata).
8 There are few ko threats against sa-thickness, whereas there are many ko threats against "thinness".
9 One area where there is a slightly different nuance from the sa-thickness of shape and sa-thickness of a go position (go kei) is sa-thickness of prospects (keisei no atsusa). In this case, it clearly implies a nuance of "somewhat better"; it implies a plus value.
10 Turning local mi-thickness into overall sa-thickness.
11 If you rush for territory, you give the opponent sa-thickness, but acting so that he cannot display this sa-thickness may be called sa-thickness with an opposite meaning.
12 The procedure to convert sa-thickness into territory is to attack.
13 Procedures are necessary for turning sa-thickness into territory.
14 You mobilise the position by seizing the initiative and take advantage of the special nature of thick go by converting sa-thickness into territory.
15 Mi-thickness must be connected with long-term trends by converting it into sa-thickness at an early opportunity.
16 But if mi-thickness and sa-thickness are confused, the opponent's defence (mamori) will be decisive.
The point I am really making is that this is a BIG subject even in Japanese (Atsuku Utsu is quite a big, dense book). Apart from the above, we covered the history of thickness theory (goes back to Honinbo Sanetsu), the differences between Japanese and Chinese theories (Chinese is based on shi), and a very easy pro-endorsed method - which proved very popular! - by the same Japanese amateur who gave us miai counting in yose for counting the value of MI-thickness.
The GoGoD seminars are available to anyone who helps with travel costs and provides a projector. This one was for dan players who found it almost all new and challenging, but most were inspired enough to buy several of the various Japanese books we referred to. This is not a plug as it's entirely non-commercial and our time is free. If you are in the BGA, the BGA will help with your costs.
Bill: In English, there are several ways of making a noun from an adjective. Often the difference simply reflects the history of the word. We say thickness, not thickity.
By contrast, making a noun from an adjective in Japanese with -mi carries a different meaning from making it with -sa. Sa implies degrees (the modern term is fuzziness), while mi does not. Atsusa thickness is thus more general than atsumi thickness, and includes it.
As John indicates, there are more nuances here.
John F. To expand a little on what Bill says, -mi added to the root of an adjective, denotes simply the existence of an observed quality and does not indicate degree. To quote a vintage example from Henderson, "even if one object be scarlet and another only tinged with pink, they can both possess akami completely" (aka- being red and akami redness). -sa denotes degree, or measurableness, so that one can compare one object's akami against another's. It does, however, add a nuance of emotion implying a sort of measurement. E.g. hana no utsukushisa might be translated as "what beautiful flowers" (i.e. they are more beautiful than usual flowers).
The vagueness inherent in atsumi is why it can be translated often as influence, and the concreteness of atsusa is why it can be rendered as solidity. But there are dangers of misnterpretation in both cases and of losing the link between the two - dangers that have long been pervasive and are really what these thickness pages are about.
To Play Thickly