Endgame Problem 12 / Solution

White play without the forcing moves  

This is one of the normal white endgame plays if black doesn't play the forcing sequence. First white plays - in gote and later - is sente.

White play after forcing moves  

If now - then later when white plays -, white cannot continue pushing at a due to shortage of liberties induced by the presence of .

White play after forcing moves  

Later, - is sente, leaving a 1/3-point ko.

White play without the forcing moves  

If the forcing moves had not been played, white has the option of descending at . This option is absent after the forcing moves have been played.