The Ni-rensei pattern
The black line-up on the right hand side is called ni-rensei (two star points). Usually, black's aim in this fuseki is to play a fast paced game. White's first two moves can be anything basically but here we are especially interested in a white ni-rensei as well because this fuseki pattern is quite popular recently.
Various strategies are possible from the position shown in the first diagram. Black can enlarge his area of control with A or immediately build a moyo with B (which would create a so-called san-rensei pattern).
Alternatively, black can make the game small-scale by approaching white's position from the inside with C or D.
Although various other moves have been played in this position
the final move which is explicitely shown is black E.
A logical approach
Since both black's and white's positions are high they invite
to build a moyo (framework) with them. Black 1 in this diagram
enlarges black's sphere of influence while reducing white's.
In that sense it's a logical approach. When black dislikes
white's option to pincer black (with A or B) he could play
black 1 at C instead.
No fuzzing around
If black's intention is to use his ni-rensei stones to
build a framework then black 1 is the clearest move:
it creates a so-called san-rensei formation which can be
further expanded with moves at A or B. Since the position
is symmetrical black is ensured of at least one of them.
Kobayashi Satoru's idea
In the starting position black is to move (has sente).
Of course black can create a moyo as in the previous diagram
figured that one should do more with the right to play first in
the symmetrical position. Black 1 aims to prevent a white moyo
first (while maintaining sente) and then build one himself with A.
The fuseki patterns evolving from this move have this idea
constantly in mind.
Making the opening small scale
If you are not in the mood to play a large scale game
(with large moyo's by both white and black) then Black 1
is the move. It splits the left-hand side, preventing white
to create a san-rensei and has follow-up's at A. Black
is ensured to get at least one of these points so black 1
is a secure invasion in white's sphere of influence.
Black 1 was played in a game between the two initiators of the
so-called shin-fuseki (new opening) period in Go:
(as black) and
In a way black 1 makes sense: it is played in the largest available
space (which is a good general lead while looking for valuable points
in the opening).
Request: Milton N. Bradley