( 980)

(Referenced by 940)

We will provide the transformation for the variation for now. We simply start with the exchange of and . But thereafter, White's four stones are in atari, so we will move to the upper edge, where it occupies the ordinary outside liberty of White's group.

Black's group has seven liberties now (3 * c, 3 * b, k), with four effective liberties for White's centre group (w, 3 * c), which is a disaster for White.

This implies that White must have made a mistake with creating this special position.

It is the exchange of the marked stones ( / ) that is harmful to White, and therefore is a grave mistake in this sub-variation.