Black Sheep Rengo 2003/Yose Tesuji

Sub-page of BlackSheepRengo2003

This part of the game discussion is actually described in the canonical J+1-group page.

white to play  

Normal endgame  

AvatarDJFlux: I am a weak player in all the stages of this beautiful game, and especially in the Yose, but one of the very few things I happen to know is that the exchange W1 for B2 in the diagram below, despite being Sente, loses points... (W1 is W174 in the BlackSheepRengo2003, B2 is B175).
After that White can exchange W3 for B4 and Black gets 5 and half points of territory. I count half point at a because both have the same chance to play first at b.

Yose Tesuji  

The Yose Tesuji for White is W1 in this diagram.

Black must answer at B2, then White plays W3! B4 is again forced to keep Black his two eyes, W5 is another Tesuji.
Here White gets 2 and half points, the captured black and white stones cancelling each other. The half point has the same reason as above. Therefore this sequence would have brought White a whole three points!

RNGS: Why "must" Black play at 2? Wouldn't 2 at 4 work?

I apologise to the Yose theoreticians, but I don't know much about tally-oh, ' don't know much about hotness... I don't know much about coolness... (to be sung on a famous R'n'B song).

Dieter: Thanks a lot AvatarDJ ! I'll try to remember this from now on.

HolIgor: The difference is sente and gote. Therefore timing is important here. Since black cannot do much white can wait with this variation till 1.25 points is the largest move. Though, actually W1 and W3 are sente.

Black Sheep Rengo 2003/Yose Tesuji last edited by on April 2, 2014 - 16:57
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