Sake bottle shape

makes the sake bottle shape, a knight's move from two stones one space apart. Also known as inu no kao (dogface) from the shape upside down (White stones in the diagram).

If does not point to the center, or other stones are in contact with these three, then the shape is not the sake bottle shape.

One proverb claims "the sake bottle shape is overconcentrated" ^[1]. Indeed, there are many cases where b would be better shape, or the jump one space further to a (horse head) would be preferable. However, it remains a flexible shape seen in pro games. See sake bottle shape, textbook example for more discussion.

However, modern top bots do not seem to shy away from this shape.

See also

• Knight's loincloth – an outward sake bottle tesuji at the edge of the board
• Cutting the sake bottle shape

Notes

[1] トックリ形はコリ形なり (tokkuri-gata wa korigatachi nari)