Shape (Go)

In the game of Go, shape describes the positional qualities of a group of stones. Descriptions of shapes in go revolve around how well a group creates or removes life and territory. "Good shape" can refer to the efficient use of stones in outlining territory, the strength of a group in a prospective fight, or making eye shapes so that a group may live. "Bad shapes" are inefficient in outlining territory and are heavy. Heavy groups cannot easily make eye shapes and are therefore good targets for attack. Understanding and recognizing the difference between good shape and bad is an essential step in becoming a stronger player.

Shape is not a rule; the surrounding position must always be taken into account. While it is useful for beginners to learn the common good and bad shapes presented here, sometimes a usually bad shape can be the best shape to play locally. This can be true if it forces the opponent to create an equally bad or worse shape, or if it accomplishes a specific tactical goal, such as the creation of eye-shape or the capture of an opponent's group.

Good Shapes

* The Nihongo|Turn|跳ね|Hane is a move to be played when black and white stones are standing side by side and the player who plays diagonally at the end of the opponent's group gains an advantage. This play turns the mutual walls, whereby a player can both expand ones influence and press the opponent down. The "Turn" at the head of two (or three) stones is used to seize the initiative and to create a thick position. [van Zeijst and Bozulich (2002) "Making Good Shape," page 55.]

* The Nihongo|Double Turn|二段バネ|Ni-dan bane, or "two-step hane" is two Turns played in succession. It can be an aggressive and appropriate move, but it generally exposes the group of stones to cutting.

* The Nihongo|Thousand Dollar Turn|千両曲がり|Senryou magari. [van Zeijst and Bozulich (2002) "Making Good Shape," pages 17-62, Tokyo:Kiseido ISBN 4-906574-73-4] The thousand dollar turn is valuable because it radiates influence into the center and one side of the board. By using its thickness, one can easily make eye-shape. [van Zeijst and Bozulich (2002) "Making Good Shape," page 54.]

* The Nihongo|Diagonal|コスミ|Kosumi is a generally conservative move that allows the stones connected by a Diagonal to be connected, even in the event of a cut, barring outside influences, as there are two cutting points. The Diagonal can also be used to attack into a shape or to solidify border territory.

* The Nihongo|One Space Jump|一間トビ|Ikken tobi, especially from the middle of three stones, is often the vital point in making good shape. An old Go proverb says, "Don't try to cut the one space jump." This is for good reason, as it is difficult to disconnect without a kikashi. It can also be the vital point for destroying the enemy's shape. [van Zeijst and Bozulich (2002) "Making Good Shape", page 60. ] The proverb, "my opponent's vital point is my vital point," often applies in regard to shape. [van Zeijst and Bozulich (2002) "Making Good Shape," page 28.] Another way to say it is, "what is good for black is good for white." That is, if you can play there first, then you can destroy their shape.

* The Nihongo|Knight's Move|桂馬|Keima is more fast-paced than either the diagonal move or the one-space jump. It is named after the resemblance to the movement of the Knight in Chess. It also makes a flexible and light shape and is useful in "sabaki". Near the edge of the board the small knight's move is used to secure a base or to link up stones. However this shape can easily be cut. Hence, you must consider the surrounding stones and be prepared to sacrifice one of your own stones to make good shape. [van Zeijst and Bozulich (2002) "Making Good Shape," page 45.] It is sometimes called the "Small Knight's Move" in order to differentiate it from the "Large Knight's Move".

* The Nihongo|Large Knight's Move|大ゲイマ|Ōgeima is a more aggressive version of the Small Knight's Move, and can be cut even more easily. It extends one square further, and is usually used in conjunction with stones already in the area that provide support for this move.

* The Nihongo|Pole Connection|棒つぎ|Bōtsugi is a connection that renders solid a series of previous free-standing stones, into a line, which allows for solidarity and more influence.

* The Nihongo|Ponnuki|ポン抜き|Ponnuki is a shape that has high defensive capabilities, in that, in order to cut any point of the shape, the opponent must either build up support around the shape or risk an atari when the invading stone is played without any support. It also exerts influence and support in every direction, and can be used to stage further attacks. This shape can be the result of playing with or without capturing an enemy stone - if an enemy stone was captured in the process, it is known as "ponnuki"; the resulting shape is a "Diamond".

* The Nihongo|Mouth Shape|口|Kou is a fundamental shape, good for forming an eye. It is half of a square, 2 stones by 2 stones in an "L". Its vital point is across the square, on the far "corner". [van Zeijst and Bozulich (2002) "Making Good Shape," page 25.]

* The Nihongo|Net|下駄|Geta is a very effective shape for preventing the escape of an enemy's stones and for sabaki.

* The Nihongo|Tiger's Mouth|虎の口|Tora no kou, or "Hanging Connection", is a one stone short of a "Diamond" shape. It is so-called because an attacking stone would be under atari immediately if played directly in the "mouth" of the group.

* The Nihongo|Lion's Mouth|獅の口|Shi no kou, or "Trumpet Connection", guards against two different possible attacks on a stone by creating two "Tiger's Mouth"s at the vulnerable cutting points.

* The Nihongo|Bamboo Joint|タケフ|Takefu is safe and can only be cut if short of liberties. [van Zeijst and Bozulich (2002) "Making Good Shape," page 29.] whereas the one-space jump is good shape for outlining territory but can be cut by "de-giri" (to push through then cut and capture the weak side). The Bamboo Joint is the essence of flexibility. It has the beauty of an either-or choice, so that even if the opponent attacks first, you have a safe response.

Bad Shapes

* The Nihongo|Empty triangle|空き三角|Akisankaku is an undesirable formation of three stones that inefficiently adds liberties and creates a weak group.

* The Nihongo|Ladder|シチョウ|Shichou is not inherently a bad shape, but the inability to recognize when one is trapped in a ladder shape that cannot be won can be fatal.

* The Nihongo|Dumpling|団子|Dango is a shape where a group of stones has been forced into an inefficient lump with few liberties, no eyes and limited ability to counterattack.

References

Books

# "Making Good Shape: Mastering the Basics, Volume 3", Rob van Zeijst and Richard Bozulich. Tokyo: Kiseido Publishing Company, 2002. ISBN 4-906574-73-4. 205 pages.

ee also

*Go terms
*Ponnuki