How to make eyes
Two principles govern defensive life-and-death. First, enlarge: push outward so your enclosed space grows, because bigger spaces live more easily — a four-point shape lives outright where a three-point shape still hangs on its vital point. Second, timing: in a small space there is usually one point that decides everything, and it must be yours before it is theirs, or the group becomes hostage (8.6). On this board the enclosed space is a straight three, so the two principles meet in a single stone — the centre makes two eyes at once and needs nothing else. When the vital point is already lost, that is when you fall back to enlarging and fighting for a ko (8.8). Black to play: live on the spot.