About Ko in a Semeai Between
Two One-Eyed Groups (2012)
Number of Ko-threats
///: This is the simple case, with a one-point eye for Black. t = ( + ) - 1 = 5. |
|
///: Black's group has a larger eye. The -/-stones are needed to reduce the effective liberties in the position that has been used so far by one. t = ( + ) - 1 = 4. A larger eye favours Black (he needs one ko-threat less than with the one-point eye), so White should try to prevent Black from getting one. However, in the problem, White cannot reach this aim successfully. |
|
///: There is the second, and shared, ko-shape in the centre. t = ( + ) - 1 = 4. This is the same result as with the larger Black eye. | |