Costly atari

Sometimes you need to play your kikashi while you can. But sometimes it is aji keshi or entails a direct loss. One common mistake is to atari a first-line hane when you are going to tenuki.

Here is an example from Rob van Zeijst's column in the Daily Yomiuri Online.

Mutual Damage  

Mutual Damage (ii)  

Giving two points komi, Black loses by one point.

But Black's atari at in the first diagram is a mistake. Black can salvage jigo if he does not play atari.

No atari  

The difference is that Black has not sacrificed a stone in the top right corner. The extra point gives Black a tie.

What about White's earlier atari? Was it a mistake, too?

Mutual Damage (B)  

After White has a dilemma. Maybe the best thing is to protect the corner.

Mutual Damage ()  

But after White is plainly lost.

If White continues to mirror with :

Mirror  

protects the corner. is tesuji. If captures at a, White plays at b.

Seki  

makes seki. Now White suffers a big loss.

Seki (ii)  

White can try , but is tesuji to kill White's corner stones.

Ko  

is tesuji. is a mistake. If Black prevents the seki, White makes a ko and wins.

Seki (iii)  

So White's early atari seems necessary to prepare for the atari with sente when Black cuts. Two similar ataris, one right, one wrong. Go is not a very easy game.

-- BillSpight

See also

• /Discussion

• Mutual damage