Kakoi

Japanese: 囲い (Kakoi)

In http://lifein19x19.com/forum/viewtopic.php?f=12&t=4250, John Fairbairn says:

The other concept, <next to ijime> is kakoi or surrounding. When I first mentioned this, some years ago, it inspired a very strong Korean amateur to remark that it was this concept that got him from 5-dan to 6-dan. It's rather hard to explain without diagrams, but <Koshida> points out that there are situations where there is essentially a choice between reducing the opponent's territory or increasing our own, and amateurs almost invariably choose reduction (in the widest sense, not just keshi). The main reason is that this can be done in one move, and a move that the opponent has to answer, and we all know there's nothing more potent than the drug sentepezam. But surrounding (kakoi) usually takes (or appears to take) several moves. Kakoi is indeed harder, but it doesn't really have to take several moves. If you can engineer play in a certain way you can do kakoi in a single move (there are examples in the GoGoD Go Seigen books), and the benefits are considerable. A reducing move eliminates bad aji for the opponent and in some circumstances may create a burdensome reducing group of your own. It does not give you any territory. But a well-engineered kakoi move gives you territory, eliminates bad aji in your area and has no downside. It may give your opponent sente, but you can't have that all the time.

Note: It is one of John's hobby horses that merely translating Japanese terms will not do, since they may convey a meaning which we don't capture in one word in English, but need a good piece of text and diagrams. The discussion is at Japanese Go Terms/Discussion and also at Charles Matthews' coined Articulation problem.

Kakoi Example 1

Kakoi Example 2