Submarine
An unsupported play on the second line. Usually inside or on the edge of the opponent's framework. A supported play on the second line is a slide.
Other names include mole play (supposedly from the Japanese), and "Subway Go", said by Takemiya of Kobayashi's style[1] . The hem play is like this:
On the edge of an open skirt, you see.
Submarine plays are usually trying first for quick life. Certainly they concede influence.
is the skirt approach. Black might also respond at a.
White plays this way, probably, to gain life in a black framework, avoiding the diagonal attachment. here won't kill the white group (the 3-3 point is still open), but is a good play for central influence.
Submarine plays accord with the current fashion for a sharp, territorial style (the 'Korean way').
If the game goes this way, White has managed something interesting by getting Black to answer the 3-3 invasion at , rather than
.
(Question moved to Quick Questions.) Thad: I have often heard that there exist a class of middlegame joseki that begin with a submarine move. Does anyone have a reference?
[1] Rich "Subway go" as I understand it is a reference to Kobayashi's perceived efficient play without aesthetic qualities, and has no relevance to the submarine move.
BlueWyvern I heard this also. "Subway Go" because it gets you where you need to go but you don't see any of the sights.