Variations: by many contributors, whose names can be viewed by clicking "Page Info" at the bottom.
Related proverb: strange things happen at the one-two point - in this case you need to know which of the two 1-2 points, of course.
If White next blocks at a, Black makes another eye with b. And if White draws out at b, Black enlarges the eye with a.
NB: if White has a stone on one of the circled points, or at a, her move at b suddenly works and Black is dead.
Finally, what about making the corner eyespace as big as possible, with here? White simply blocks at and there is no way to make life.
Go to Problem 3