One Thousand and One Life-and-Death Problems / Problem 92 discussion

Problem 92  

Marc: Black to live. The book gives 1 as the correct answer. However, if black plays a instead of 1 the group is still alive plus black saves the stone below a.

Continuation  

Shaydwyrm: A play at allows white to play at , creating a direct ko as shown below.

Direct Ko  

Shaydwyrm: White throws in a stone at to create a shortage of liberties. Now black has to capture at and a direct ko commences.

Continuation  

Imagist: Just for those of us who have difficulty seeing shortage of liberties, white finishes the ko by sealing it. Black cannot play a for a connect-and-die because of shortage of liberties (except as a ko threat).