(Referenced by 37; 71; 715)

This is the classic 1988 sequence.

To capture Black's upper right group, White needs one local move that occupies liberties of that group.

She may force Black to take a liberty of his group (, ), but will lose two liberties of her own group (, 1) in the process, too, not only one (1). This effect will lead to the gain of two points for White (the black prisoner at 1), mentioned above.

Black needs three moves to capture White's group.

Relevant for the semeai is a "distance" - different number of moves needed by each player - of two moves (three for Black vs. one for White).