The Kobayashi Fuseki (Kobayashi Formation) is the pattern for Black shown below. It is named after Kobayashi Koichi who used it steadily at one point in his career. This fuseki has been actively played for some 20 years now. It is similar to the Small Chinese fuseki in that Black sets up a specific formation between the white corner in the lower left and Black's own open komoku stone in the lower right as part of a strategy for playing against a later white approach move there. It is an aggressive, fighting strategy.
The position along the bottom has a defect at e where White can invade rather easily. The other main variant in the Kobayashi is for Black to play 7 at f, attempting to eliminate the defect. However, this naturally gives White more options in the space around the lower right so opinions are divided on the placement of 7.
Black intends to use plays against an approach move in the lower right to naturally enclose the bottom side. At present the normal approach for White is the rather distant move at a. This is because closer moves tend to allow Black to play more aggressively:
- a: This is the usual approach. Black prefers to shoulder-hit.
- b: White strives to stay light; black usually responds at d and white tenuki.
- c: Black responds with one-space high pincer or two-space high pincer.
- d: Black wants to directly profit from attacking severely with a close pincer.
As with the mini-chinese, Black's ability to play this fuseki depends on White choosing not to answer Black 5 with a pincer. (See preferring to pincer.) Another way to counter it is to approach the right-hand corner. So if you don't like playing against the Kobayashi, you have only yourself to blame if it shows up in your games!
- Charles Matthews' excellent series of articles on the fuseki, now available at Jan van der Steen's site, covers the Kobayashi in considerable detail starting in chapter 18. --Dave
- The Kobayashi Opening Go World Number 87, page 53.
- Chinese and Kobayashi fuseki