( 976)

With the single throw-in, White must enforce the two exchanges of / , and / , in sente, to have Black's hanezeki-directed liberties occupied. Compared to the Punishment Semeai Liberty Level, White started the ko a bit too early (but in time with respect to the liberties of her centre group).

We have got the same situation as with the gote-sente-combination in the main line of Joachim's Ko-Semeai ( 1005), with five liberties for White (2 * w, 3 * c), seven liberties for Black (3 * c; 3 * b, k), and Black's ko-threats , and , unused on the right side. Thus, so Black will need one external ko-threat to win.
Please note that it would not have any effect, if Black played the Hanezeki Exchange ( / ) on his own. Even thereafter, the exchange of / in sente is still White's privilege.

:
Even if the Punishment Semeai Liberty Level is reduced here, compared with the double throw-in, there are no valid "quick" Black ko-threats on the left side. Seven liberties for White's -group (5 * x, 1, 3) simply are one too many. Please note that we inserted the beginning of the Nakade Sequence ( / ) again.

:
White connects the ko.

:
White wins the Punishment-Semeai by one move.