Ugly sagari
HolIgor: I would call this ugly sagari tesuji. It appear with two unfriendly stones that cut off our forces and there is some shortage of liberties. The following diagram is just a general scheme. But the move is useful to remember.
Dieter: Let's explore the alternatives.
recaptures at
and it's an approach ko. Black must make an approach move at a to make it a direct ko.
unkx80: I believe this is an instance where the "ugly sagari" is the only correct move.
John F. Excellent name! And like the ugly duckling it can turn out to be a beautiful swan.
AYHAL? Another alternative to consider which is often useful:
unkx80: However, this results in a ko when the "ugly sagari" tesuji wins the capturing race without ko.
See also