Tsumego From Games 37 / Solution

Sub-page of TsumegoFromGames37
The key point  

B1 is the key point. After this White can either try to fight a ko which she cannot win (taking the whole board into account) or just let Black live.

Peaceful - Black lives  

If White chooses the simple variant and lets Black live, then W1 capturing black+square is a good point. White makes enough territory below black+square to make the game close. (Bill pointed out that B6 is better endgame technique than a).

Fighting the ko  

If White persists on trying to kill Black and plays W1 through W5, then B6 brings on the ko. Note that Black is the first to capture so White has to find the first ko threat.

Comparing with the peaceful variant it should immediatly become clear that White has to find very large ko-threats to make up for the difference. The problem is that Black has so many internal ko threats.

Ko threats (1) (8 at 5, 9 at white+circle)  

Each Black play is a ko threat.

Ko threats (2)  

If White persists then the ko threats B7,B9 even make some additional points. By now Black has played some 10 internal ko threats. Try to find 10 ko threats for White which are at least as large as losing the ko (Black captures another 7 white stones) plus make up for the points around B3 which were White's territory in the peaceful variant.

You won't find enough ko threats.

So White is clearly better off not fighting the ko, but letting Black live.

See /Attempts for some failures and an interesting "long sequence".

-- Dave, Arno, unkx80

Tsumego From Games 37 / Solution last edited by ArnoHollosi on July 28, 2004 - 09:55
RecentChanges · StartingPoints · About
Edit page ·Search · Related · Page info · Latest diff
[Welcome to Sensei's Library!]
Search position
Page history
Latest page diff
Partner sites:
Go Teaching Ladder
Login / Prefs
Sensei's Library