Cutting the sake bottle shape

Cutting the sake bottle shape

As one can see here, the sake bottle shape created by in a can be cut at the weak point in b, where Black’s weaknesses are marked . Black can, however, choose which two of his three stones to keep connected, by playing as in c or d, where the cut-off stones are marked .

Another way to cut (ladder-breaker required)

Another way to cut is with the - combination in e, which is only possible if White has ladder-breakers for both ladders starting at in e, to prevent Black playing f or its mirror image. If White does have such ladder-breakers, Black’s cut-off stones may need to escape – for example with at in g.

A third way to cut off one of the two bottom stones is shown in h; however, Black again gets to choose which and has the option of reducing this to f (or its mirror image) if, instead of defending with , he attacks at . Hence White again needs both ladder-breakers, in which case in h does not capture .