I have long had a bee in my Tam o' Shanter about the word "thickness." Not quite as ferociously buzzy as "yose" (wasp) or "goban" (hornet), and perhaps for that reason I've done little thinking about the term itself, just confining myself to trying to correct misconceptions about what it means in practice.

I'm not sure why, but I got to thinking about it last night, however, and this morning I can present the, to me rather satisfying, results of a little research.

The root term we are concerned with is "atsui" 厚い. If you look that up in a modern Japanese dictionary, e.g. Kojien, you get a list of meanings as follows: (1) thick, of a physical object, denoting large distance from front to back; (2) great (of affections); (3) enormous, extreme; (4) heavy (of stature), imposing; (5) brazen, shameless (from the sense of thick-skinned).

If you look the character up in a modern Chinese dictionary you get a similar range: thick, deep, kind, large, generous, strong (of flavour).

So the specific meaning "thick" is present but hardly dominates. Indeed, a major modern go book on thickness (by the Igo magazine editorial team) also quotes Kojien and says the meanings that apply to go are (3) enormous and (4) heavy.

That is questionable on two grounds. One, limiting ourselves to modern usage, is that the root "thick" is used in various ways in go, and at various stages of the game, with somewhat different nuances. To quote Hayashi Yutaka first (historian and former editor of Kido), the uses span: atsui, atsugaru, atsusou de usui and atsumi. Actually even this list is defective: we should add at least "atsuku suru" and "atsui go" (thick go style), and terms that incorporate the "thick" character such as 厚壯.

But the bigger reason for questioning modern usage is that the term is clearly of very long standing, and at the time it was devised 厚い had rather different meanings. This is not unusual. The first few pages of any book on classical Japanese will introduce examples such as "omoshiroi" which means "interesting" nowadays (though the go usage is usually "better for one side"), but in older texts means either "elegant" or "wonderful". Because classical Japanese was used up until the middle of the 20th century (and is still taught in schools), schoolchildren often have a dictionary of the old language. In there, faux amis such as "omoshiroi" are asterisked. There are very many asterisks, and one of them is appended to "atsushi" (the classical form of "atsui").

To take first an old-language school dictionary by the great linguist Dr Kindaichi Kyosuke, he gives just two meanings: (1) imposing, dignified; (2) enormous.

To go to the other extreme, we can refer to the massive Morohashi dictionary, which is really a Chinese-Japanese dictionary but he also gives the old Japanese meanings (and citations, of course). His list of basic meanings is: (1) heavy; (2) numerous; (3) large; (4) deep; (5) long; (6) noble, august; precious; (7) dark, dense (of colour); (8) polite.

As you can see, "thick" does not even earn a mention in the old language (and even "strong" is missing). These dictionaries were compiled in the days before computerised corpus linguistics, and I suspect old examples of "thick" could be found (although "futoi" was available for "thick" meanings, and "atsui" of a sleek, glossy pelt should also be mentioned), but it does seem inescapable that the preponderant original meanings have something to do with "size" and the primary nuance is "imposing" (or, ugh, "awesome"). This can perhaps be reinforced by observing that there is a verb "atsumaru" with the same root. It uses a different character but has the meaning of "assembling in large numbers" and, as a first hypothesis, could be etymologically related. I might also add that Morohashi's citations from Chinese, where he typically quotes the ancient Chinese commentators who gloss the oldest texts, give 大 (large) and　多 (numerous) as the core meanings of 厚. Further, "usui" (modern "thin") is given as the antonym of "atsui" in old dictionaries, but with number-based old meanings such as "scant."

There are quite a few more similar linguistic points that can be made. To briefly mention a couple, Morohashi identifies "atsuku" and "atsuku suru" as distinct meanings, rather as Hayashi does in go. For "atsuku" he gives only "greatly, numerously" and for "atsuku suru" he gives (1) be prudent; (2) make numerous.

There are also reinforcing points that can be made with reference to "atsumi" (thickness) in go. "Atsumi" has generally agreed attributes, such as it should be "outward facing." One other attribute is that it should be "early", i.e. created as early in the game as possible. The idea here is a ratio one: if you have 6 stones to his 3 early on you have a big advantage. But if you let play continue here so that you have 9 to his 6, your advantage has dissipated. I think you can see this numerical idea at work in AlphaGo's willingness to dive in at the 3-3 point against a star stone and then attack the outside stones early on before they becoming "imposing."

My own conclusion is therefore that my misgivings about the term "thick" (and likewise "influence") were entirely justified. Unfortunately, I can't think of a better term, but I suspect it's enough just to point up this size/number aspect for most players to start appreciating the true meaning. It even seems to extend to all the go usages of "atsui," at least after a little explanation, which I will omit here.

Atsui also means "hot" doesn't it? And in American, "hot" means "sexy".

So thickness is sexy.

PS i believe that "omoshiroi" is sometimes used, colloquially, to mean "I don't believe you", in the same way that English people might say "interesting..." to someone talking nonsense, to whom they do not wish to give overt offence.

Muzukashi, desu-ne?

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i shrink, therefore i swarm