18. Rescuing an Endangered Group
Exploiting a Defect in the Opponent's Position

by Richard Bozulich

Go players often encounter situations in which one of their groups gets into trouble. However, there is often a way to save the group by finding a tesuji that exploits a defect in the opponent's position. The problem below is an example.

Black to play
Problem. Black to play
Black's marked stones seem to be trapped, but there is a defect in White's position at 'a'. What is the tesuji that will enable Black to exploit this defect and escape with his group?