Tsumego From Games 45 / Solution

Status.  

The status of the White group is unsettled.

If White plays first, White lives; and if Black plays first, White dies.

White plays first

If White plays first, there are two ways to live.

Method 1

Method 1.  

Using the special properties of the corner, White plays and away from the corner.

Method 1.  

If tries to destroy the eye, then connects, and captures Black with a connect-and-die with and .

Since White captures three stones, White lives.

Method 1 (Variation).  

If makes a placement instead, then the descent at allows White to live with a seki.

Method 2

Method 2.  

White can cut at , atari at before making the play at .

If the outside is all Black territory, then this is better for endgame reasons.

Method 2.  

If , then connects. Black finds that connecting at a is not possible.

Not a method

Not a method.  

is not a method to live. The throw-in at kills.

Not a method.  

White's strongest resistance is at and . However, can atari, so the two Black stones chain at the bottom is capture two, recapture one which curiously gives Black an extra liberty in the capturing race, so White dies.

Still ko?  

Rich: Doesn't white still have a direct ko?

Black plays first

If Black first, there are many ways to kill. Two ways are shown here.

Method 1

Method 1.  

After White does not have enough room to live. Even if White had a stone on a, she would have, in effect, only 6 stones in a row on the second line. See eight live, six die.

Method 2

Method 2.  

kills by preventing the connect-and-die as shown in the White plays first diagrams. Practically, this is usually better than Method 1 because it affects the outside more.