About Ko in a Semeai Between
Two One-Eyed Groups (2012)
The Effect of the Hanezeki
So far, we did not consider the effect of the hanezeki. With the addition of the hanezeki, it is important to note that White can safely capture its tail when Black's group in the semeai has only seven liberties left. This is the Punishment Semeai, ending in Black's defeat. Now, the time has come to stress that there is a difference between "physical liberties" (actually seen on the board), "effective liberties" (relevant for taking a group really off the board), and "ko-fight liberties" (relevant for calculating the outcome of a ko-fight). The Punishment Semeai refers to effective liberties, neither to physical liberties, nor to ko-fight liberties. Perhaps you have noticed that throughout this entire chapter - until now - Black's group in the semeai always had eight physical liberties in the very beginning. | |