Tesuji And Katachi

British Go Journal No. 8. Spring 1969. Page 5.

John Tilley

This is an introductory article aimed especially at the weaker player. However, some of the examples are of an advanced nature, so I hope there is something for everyone. First of all, what are tesuji and katachi?

A "tesuji" is a clever local play, which may be either offensive or defensive. They are usually difficult to see and frequently work miracles!

"Katachi" - or shape - is the act of placing stones in certain patterns to achieve maximum results. This means that two stones do the full work of two stones, and not that of one or three.

A good knowledge of tesuji and katachi enables one to play quickly and accurately, as only a very few alternative moves come to mind as being good possibilities and hence need be considered for each.

Diagram 1

Diagram 2

Diagram 3

As a starting point, consider Dia 1. The three stones have seven liberties. In Dia 2 three stones are seen to have eight liberties. As a battle depends on liberties, patterns like Dia 1 are bad and tend to lose games quickly.

However if the triangle is filled in by a stone of the opposite colour, as in Dia 3, then black 1 can become an excellent move. The formation in Dia 1 is called an empty triangle, for obvious reasons.

Another essential rule is to not over-concentrate your stones. Stones should not be joined together too early in a game. The two above rules are best illustrated by an example. I shall try to use joseki as examples wherever possible. Study of joseki is a vital part of Go; it teaches katachi and tesuji applicable to the whole game.

Diagram 4

In Dia 4 white has approached blacks stone with a small knights move. This is the most common way of attacking the handicap stone.

Playing in contact with a stone strengthens it. So both black and white will grow strong around their mutual contact point. It should therefore be noted that black 2 is a defensive move; Black is satisfied to be able to build a safe group and is prepared to let White build one too. White replies with 3. Where should Black play his fourth move, at A, B or C?

Answer A
This is a very bad play. Black has joined his three stones together too early in the game.
Answer B
One way of playing, but not seen very often because though Blacks corner becomes large it is somewhat open to invasion.
Answer C
The most common and best play. Blacks three stones exert their maximum strength. This formation occurs all over the board many times.
Diagram 5

White continues with 5 in Dia 5. Where should Black play next; A, B, or C again?

Answer C
A very vulgar play leaving a lot to be desired. It not only produces a vacant triangle but joins his stones together too early and lastly does not protect the corner at all!
Answer B
Bad. This does not protect the corner. But it is not so bad as c. (Sometimes this is correct in other joseki but here it is not.)
Answer A
Correct. Black produces an efficient shape and protects the corner. Also he prepares to attack White should he play elsewhere.
Diagram 6

Diagram 7

Dia 6 shows the finish of this joseki. Suppose White played elsewhere with his move 7. Now it is Blacks turn. 1 in Dia 7 is correct. After black 3, white has to resort to a vacant triangle 4, to escape to the centre. This is obviously a good thing for black.

Diagram 8

However sometimes White plays as in Dia 8. Black should have no hesitation in playing as shown, separating white 2 and 4. With 13 and 15 Black builds a large wall.

Diagram 9

Another common example where vacant triangles occur is seen in Dia 9. This splitting attack of white 1 divides the black stones. White waits for a black mistake, considering that this is a handicap game. If Black plays as in Dia 9 he should have no trouble in setting up a good position. If white wants to escape he must make a vacant triangle after black 4.

Diagram 10

Also note that Whites move 5 in Dia 10 has a bad effect as, if black follows the rest of the diagram, he will build up a huge wall on the right hand side of the board. This promises him a large territory later and makes white 1 much weaker than before.

At this stage I shall give some common examples of simple katachi. However these are all discussed in the excellent book "Go Proverbs Illustrated" by Kensaku Segoe. As every Go player should buy, borrow, beg or steal this book I will not repeat it here. (It is an especial must for all beginners.)

Two important proverbs are:

Diagram 11

Diagram 12

1: Play "hane" at the head of two or three stones in a row.

In Dia 11 Black plays hane at 1 and White answers in good shape with 2.

In Dia 12, black 1 threatens to play A and thus white has a bad shape.

Diagram 13

Diagram 14

Diagram 15

2: Learn the eye-stealing tesuji.

Blacks two marked stones in Dia 13 form the eye-stealing tesuji. The important point about this tesuji is the relation between the two Black stones; it is of no importance whether the other stones are there or not.

White 1 in Dia 14 and Black 1 in Dia 15 both illustrate the eye-stealing tesuji. Please convince yourself of this.

Diagram 16

For an example of the two above proverbs the joseki of Dia 16 is worth studying. It is an unusual variation of the small avalanche joseki. (See issue 5, page 10.)

Up to white 12 everything is quite normal. However, black 13 is unusual. This move is the eye-stealing tesuji. White has no choice but to play 14. If he plays elsewhere Black will play at 16, White captures, Black plays 15 to force white to fill in, then 14 and a ladder develops.

Black 15 threatens a snap-back at 16 and white answers. 17 is vital to capture the two stones. The rest of this joseki is fairly obvious and the outcome of the game* will probably depend on the survival and use made of Blacks three stones.
* [BGJ had 'come'.]

Diagram 17

Diagram 18

9 fills at 4.

Another useful piece of advice is dont make dango'. (A dango is a formless and solid mass of stones.) Dia 17 shows the two point high handicap pincer. This is a common joseki and should be studied.

However, move 18 is odd. Black sacrifices, as shown, two stones 12 and 18, and builds up a large wall in exchange. Note black 26; this effectively cuts off 15 and protects the cutting point below 14.

Suppose White plays as in Dia 18. White 7 is a bad move as black can play the rest and now capture white if the ladder is favourable for him, or he can pursue the white dango into the centre with great advantage and White will be at a loss as to how to deal well with the situation.

Diagram 19

As a final example consider Dia 19. It shows part of a game between Rin (Meijin) as black and Sakata (Honinbo) as white. The game was played on 1st September 1966.

Both players have a weak group resulting from a difficult invasion into Blacks territory. The marked stone was a nuisance later as it is not yet completely captured.

  • White 1 is essential. For otherwise black can play one point below 1 to capture two stones.
  • Black 2: Blacks obvious move is at 4. However, he must play the 2-3 exchange first. Otherwise Dia 20 results. After 10 blacks upper group has a bad form and he will find it hard to save both it and the lower group.
    Diagram 20

    Diagram 21

    7 fills at 2.

  • White 5: It seems obvious to play hane as in Dia 21. However, 2-6 forces white into bad shape.
  • Black 6: Eye-stealing tesuji.
  • White 7: Hane, good form.
  • Black 8: Natural.
  • White 9: Tempting to play as in Dia 22. However, a similar sequence to Dia 21 results in a bad shape for White.
    Diagram 22

    5 fills at 2.
    [BGJ Dia 22 erroneous and confusing. Reconstruction attempted.]
  • Black 10: Necessary.
  • White 11: Now a good play.

Black finally won the game by four points.

In conclusion, katachi and tesuji provide an essential short cut to finding the correct best play in any position. They both speed up and improve your play. Three useful suggestions are:

  1. Read "Go Proverbs" - essential information on hane, eye-stealing tesuji,
  2. Study professional games - investigate the katachi as in the example above. Dont be frightened about not understanding each individual move, get a feel for which is the right move.
  3. Study and understand joseki - these provide a great source of material for learning about tesuji and katachi and, though they may not be applicable everywhere, they will be of great value.

[ Diagram 22 as published]

7 fills at 2.


This article is from the British Go Journal Issue 8
which is one of a series of back issues now available on the web.

Last updated Thu May 04 2017. If you have any comments, please email the webmaster on web-master AT britgo DOT org.