Eyes, life and death · Lesson 24
Ko threats and ko for life: why play elsewhere first?
After a ko capture, the opponent cannot immediately recapture. To keep contesting it, play a threat elsewhere that the opponent must consider: a ko threat. Answering it is responding to the ko threat.
If the opponent answers the ko threat, you have a chance to recapture. They may instead ignore it and connect the ko, ending that fight. Compare the cost of losing the ko with the damage from carrying out the threat elsewhere.
A group that must win a ko to survive is alive only through ko. This differs from unconditional life, where even the opponent playing first cannot kill it. Not yet captured does not mean safe.
The diagram revisits the ban on immediate ko recapture; no off-diagram threats are provided. Real ko threats require the whole board. Do not assume a useful threat exists somewhere unseen.
Before taking the ko
After taking the ko
Original lessons by Yiban ·