Shape for DDKs -- and thickness, too!
Posted: Sat May 30, 2015 10:32 pm
I have prepared some thoughts and material on the basics of shape and thickness. I by no means intend this thread simply to reflect my thinking and opinions. Please join in the fun. 
Shape for DDKs
Discussions about shape often start out by classifying some shapes as bad, others as good. But IMO the basics of shape come before such classifications.
What is shape? A shape is a local configuration of stones of the same color. Shape as a topic is about the efficiency or effectiveness of shapes. The study of shape, then, includes how shapes relate to stones of the opposite color. Shapes can be overconcentrated, so that they use more stones than necessary to achieve their effect; they may even be heavy, so that not only do they invest a number of stones, they do not achieve their effect and are weak. On the other hand, shapes can use too few stones to achieve their intended effect, and can be thin and weak.
Suzuki Tamejiro, the teacher of Kitani Minoru, emphasized three basic two stone shapes for beginners, the nobi, a solid extension to an adjacent point, the kosumi, an extension to a diagonally adjacent point, and the tobi, a one space jump. The most frequent moves in go form one of these shapes. Depending on the circumstances they often go by different names. Of course, in themselves we cannot say whether these shapes are good or bad; we have to take into account their surroundings. I will also emphasize these shapes, as well as another one, the keima, or knight’s move, an extension two points in one direction and then one point in a perpendicular direction.
Locally the nobi is strong. It cannot be cut. It is also slow.
The next two diagrams show the nobi with an opposing stone.
The kosumi develops more quickly, but it is not as strong as the nobi. It can be cut if Black ignores the threat to cut. The next diagrams show the kosumi with one or more opposing stones.
This kosumi, AKA hane or block, is an attacking play, but it can be cut.
This hane is normally a very good play. Go proverb: Don't look, hane at the head of two stones.
Many players are unaware of this play, but it is normally a good one.
The tobi develops even more quickly, but is weaker than the nobi or kosumi. White to play can cut it — but usually does not.
This jump attachment is often seen.
The keima, or knight’s move, is quicker than the tobi, but, curiously, harder to cut.
White may cut with
and 
, but 
may be able to capture in a ladder.
is often seen.
Shape for DDKs
Discussions about shape often start out by classifying some shapes as bad, others as good. But IMO the basics of shape come before such classifications.
What is shape? A shape is a local configuration of stones of the same color. Shape as a topic is about the efficiency or effectiveness of shapes. The study of shape, then, includes how shapes relate to stones of the opposite color. Shapes can be overconcentrated, so that they use more stones than necessary to achieve their effect; they may even be heavy, so that not only do they invest a number of stones, they do not achieve their effect and are weak. On the other hand, shapes can use too few stones to achieve their intended effect, and can be thin and weak.
Suzuki Tamejiro, the teacher of Kitani Minoru, emphasized three basic two stone shapes for beginners, the nobi, a solid extension to an adjacent point, the kosumi, an extension to a diagonally adjacent point, and the tobi, a one space jump. The most frequent moves in go form one of these shapes. Depending on the circumstances they often go by different names. Of course, in themselves we cannot say whether these shapes are good or bad; we have to take into account their surroundings. I will also emphasize these shapes, as well as another one, the keima, or knight’s move, an extension two points in one direction and then one point in a perpendicular direction.
Locally the nobi is strong. It cannot be cut. It is also slow.
The next two diagrams show the nobi with an opposing stone.
The kosumi develops more quickly, but it is not as strong as the nobi. It can be cut if Black ignores the threat to cut. The next diagrams show the kosumi with one or more opposing stones.
This kosumi, AKA hane or block, is an attacking play, but it can be cut.
This hane is normally a very good play. Go proverb: Don't look, hane at the head of two stones.
Many players are unaware of this play, but it is normally a good one.
The tobi develops even more quickly, but is weaker than the nobi or kosumi. White to play can cut it — but usually does not.
This jump attachment is often seen.
The keima, or knight’s move, is quicker than the tobi, but, curiously, harder to cut.
White may cut with
and , but may be able to capture in a ladder. is often seen.