: ( 648go)
White connects her stone in the upper right.

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Black has to play this atari before continuing at the top.

If he captured with first, White would choose Dany's Sacrifice, and win the Punishment Semeai.

It is also too early to play the push at the top; please refer to ( 648ap) for details.

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It is best for White to connect, as she is better in the Capture Variation than in the Semeai Variation.

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Black plays his kikashi at the top.

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Black is also able to capture White's single stone at the upper edge now.

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Black connects at the upper edge.

Now - all valuable points outside the Main Semeai area have been taken - you can easily realise that a White push at is not necessary.

If White played this reduction of Black's territory in the left centre, Black would achieve a move of his own to also reduce White's territory in the upper right in return. The net effect of this exchange is zero.

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After Black played , White has to force in the centre.

If she let Black occupy the point , her score in the Semeai Variation would become worse.

Black plays 1/1 reduction.

Capture Variation:

Compared to the superordinate variation ...

• Black got an additional point of territory in the left centre.
• Black destroyed an additional point of White's territory in the upper right corner.
• White captured Black's stone in the lower right, so gaining two points.

In total, gains and losses compensate for each other.

White + 2 => White + 2

Semeai Variation:

Compared to the superordinate variation ...

• Black got an additional point of territory in the left centre.
• Black captured one White stone less in the left centre, so losing two points.
• White captured an additional Black stone in the upper right, so gaining one point.
• White captured one Black stone less in the lower right, so losing two points.

In total, gains and losses compensate for each other.

Black + 4 => Black + 4