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Fuseki
Miai

 

Miai in the Fuseki
    Keywords: Opening

The concept of miai is important in the fuseki as well. Playing situations that contain miai assure one of being able to achieve at least one of two aims regardless of how the opponent chooses to counter your strategy.

[Diagram]
Diag.: Black's strategy

In this common fuseki, Black chooses to play against White's position on the left instead of continuing his own development on the right, for example by forming a sanren sei by playing 1 at a. When White answers with the common attachment at 2, Black plays the joseki of 3 and 5 and finishes with the high extension at 7. The modern popularity of 7 instead of the alternative play at b is attributed to Takemiya Masaki and is based on a miai strategy.

Black plays 7 in order to increase the value of a follow-up at c. He then considers c and a on the right to be miai and is content to play whichever White does not take for herself.


[Diagram]
Diag.: White chooses the left

White chooses to counter Black's intentions on the left so Black makes his sanrensei on the right side. To play like this Black must be willing and able to handle the white invasion at a.


[Diagram]
Diag.: White chooses the right

Here White decides to prevent a black formation on the right and splits the side with the wedge 1. As a result, Black is able to follow up on the right by approaching White's lower left corner at 2 and White will probably answer with something like 3.

Note that White 1 is also a typical example of miai. The follow-up here is for Black to play against the white stone with either a or b and for White to reply with an extension in the direction away from the approach stone. Since both directions are open for White (are miai) there is no urgent play on the right side for Black at this time. The future course of the game may make one direction or the other more valuable. If that happens the miai situation disappears and the right side will become more urgent.

The equivalence of the left and right side is much less clear here than in the examples on the miai page. There is no simple calculation this early in the fuseki to show that a play on the left and a play on the right have the same value. In professional play that equivalence has to be demonstrated over the board. In the fuseki above there are professional examples of White choosing both the left and the right with no clear advantage from either choice. For the moment, we can consider them miai (until someone comes along with an approach that demonstrates otherwise!).

DaveSigaty

Update - When I wrote the section above I was basing it on materials in Otake Hideos Fuseki Theory which was published at the end of 1986. The final sentence turns out to be rather fateful since it seems the pros have meanwhile demonstrated that the left and right side are not miai!

Analyzing this variation using the program Kombilo and the game collection from the Go Games on Disk CD (January 2002 update) the following history of the variation can be charted:

  • First appearance November 1983 in the Honinbo League game between Takemiya (Black) and Takagi Shoichi.
  • Appeared a total of 65 times between 1983 and 1995.
  • In those games White played in the middle of the right side 42 times and won exactly half of the games.
  • White also played on the left side in 16 games but won only 25% of such games.
  • Various other moves were played 8 times with no special trend in results.

The variation does not appear in the collection at all in the period 1996-2000. It was played once in May 2001 but this appears to have been an isolated incident.

It appears from this that the white play on the right side was superior to the alternative choice on the left. However, once White played on the right, Black could not do better than equal results. Since it is Black that initiates this line, the disappearance from top level professional Go after 1995 seems to reflect Black's dissatisfaction with his results.

One last interesting point. The left and right were officially viewed as miai from the first (hence Otake's inclusion of it as an example of miai in a book for amateurs written in 1986!). However, the choices made between the left and right were not balanced in actual play. The professionals first concentrated on splitting the right side. The play on the left came later (because the right side failed to yield an advantage?). Of the 16 games where White played on the left, 14 were played in the 90's and 2 were played in 1995 shortly before the variation fell out of favor.



This is a copy of the living page "Miai in the Fuseki" at Sensei's Library.
(C) the Authors, published under the OpenContent License V1.0.