Nowadays the most orthodox way for White to deal with the Kobayashi formation is to play the restrained, two-point low approach (large knight's move approach). A steady accumulation of theory attaches to this play.
If Black simply takes the corner with 2, White is free to play at 3, which is certainly a reasonable plan. Black has another popular choice at A, with a more direct eye on building up the lower side framework.
Black can continue with 1 here, immediately or in the near future. Then 2 becomes the key point - if White doesn't occupy it, Black can play at 2 for an excellent attack that builds up the framework.
Extending back as far as 3 was played by Cho Chikun (game 2 of the 1986 Kisei match) against Kobayashi Koichi himself. Not in fact a new move, it had appeared in the Shinjin-O match 18 months before. It is rather natural for Black to answer at A, but B and C have been tried more recently.
As long ago as 1949 Go Seigen had tried extending back to 3 this way in a game against Sugiuchi. There is however a puzzle about this shape. It is not an idea that would occur to anyone adhering to what you could call the infantryman's theory: that groups established inside an opponent's large-scale framework have a first duty to hold a piece of ground. According to that logic, extending on the third line would be correct.
The new book Jungsuk in Our Time from the Korean Baduk Association addresses the variation, giving this line. The comment, that 3 is more modern and centre-oriented, is a little throwaway. White is certainly aiming at 5, building influence while setting up an invasion of Black's framework. The idea behind Black 6 is to retain the initiative - i.e. to prevent White dealing lightly with this side and moving elsewhere. It is argued that White 9 becomes required. In any case White 3 invites some complex developments.
If Black instead plays the shoulder hit 2, White 3 sliding to the second line is the usual answer. Now Black tries A, B or C. These variations have been subject to constant revision, in a tussle over defects in White's shape.
(White 3 at A, Black at D is also known, ending up with a position the same as after White 1 at A, Black at D, White at 1. Then Black typically pincers to prevent White establishing a base on the side.)
For example this has been common in recent Chinese games. White reacts cautiously to the covering play 6, which on the face of it is a stretch for Black. Cutting at A is postponed while White settles with 9.
Black 4 here can be seen as an allied idea, but with more emphasis on attack. There is a complex textbook sequence starting with 6 at A, but it has fallen into disrepute in this position, the reason being that the marked black stone can end up less than ideally placed. So now the tough-minded plan of Black 6 is standard. What about the immediate peep Black 8?
In a game Rin Kaiho-Ryu Shikun (Tengen match 1996 game 2) White resisted, trading the outside for points in the corner. This sort of result may be hard to evaluate. There is the chance that Black's other stones will look misconceived.
Therefore it is usual for Black to defend with 8. This gives White a chance to guard against the peep on the second line. This variation has been seen more than once.
An alternative is this idea of Ma Xiaochun. White played calmly with 1 and 3, then shortly afterwards invaded at A.
More ideas on this set of variations in Chapter 10 of the new book The World of Chinese Go by Guo Juan (Kiseido).
            
First published 8 February 2001 as On Your Side on MindZine,
© Charles Matthews 2000.