Tsumego From Games 4
Keywords: Life & Death, Problem
This comes from a three-stone game with me (1k EGF) playing White.
The attention is drawn to the upper right corner. The White group is trying to live thus cutting the top center group from the upper right corner. Had I calculated it a bit earlier, I'd have left this as aji. Black can kill this group.
My opponent played 1 and 3. If I continued with a, Black b would still have killed me. If White b, then Black c kills. But, there was a tesuji to save the white group.
If Black connects, White lives with 5. White 5 at a would be a big mistake, for Black b will make miai of 5 and c to kill.