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February 1999's Go Answer of the Month


Dia 1 - Seven space big eyes.

Dia 1

A more convoluted question this month. I hope you know the answer to the first part without having to think about it.


Dias 2 & 3 - Status.

Dia 2   Dia 3

White can live in gote. Black can get a gote seki (White 2 elsewhere). After either, White gets probable sente pushes at A, B and C.

It is theoretically possible for Black to almost fill this big eye with a rabbitty six, thus killing White. But it is unlikely that would happen. If White should tenuki with 4 in Dia 3, then Black cannot be prevented from doing this so that White is now dead. It actually takes Black 20 moves to remove the White stones if a capturing race occurs and White would be beter off with the seki in that case.

Dia 4 - A or B?

Dia 4

Playing at A is worth 6 points in gote as shown in Dias 2 & 3.
Playing at B captures 4 stones, again in gote. Later on another gote move for White connects the capturing stones or a Black gote move recaptures one stone. The net result is somewhere between 5 and 7 points for White.

If these were the only plays left on the board the plays are:

The last sequence is bad for Black. The others suggest that playing at B is one point better than playing at A.

Dias 3 again & 5 - Aji?

Dia 3   Dia 5

Once Black has played 1 in Dia 3, the first player to play again has two ko threats. Black gets two large ko threats - 3 and 5 threatening to kill White. White gets two small ko threats in Dia 4 - 2 and 4 threatening to live with 6 points.

And the status doesn't alter as the outside liberties are removed.


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