Tewari Example 5

Kobayashi Satoru (W) - Imamura Toshiya, 2006  

From this Asahi newspaper site. Black played - , allowing White to play the big point at .

Ishida Akira, commenting on the game, said that if Black had not played , but had taken a big point himself, for White to play at 1 would have been absolute. He appealed to the following tewari diagram.

Tewari  

In this position the exchange, - , is bad for Black.

This example is also present in Ishida Yoshio's Dictionary of Basic Joseki, vol.3.

LZ analysis

This section used to be headed "LZ does not agree with Ishida's analysis". But Ishida does not say that above is the best move! Ishida's analysis is: if black doesn't play at the top left, then white should play at the point of . Leela Zero does agree with that part. Specifically, if is at , then at is rated as one of several equally good options. KataGo supports the same conclusion.

Leela Zero's analysis  

Before , LZ estimates Black's chances at 40%. After this exchange they drop to 30%. Most likely this is because Black sacrifices the corner, while living there is more to LZ's liking.

Leela Zero's preference  

LZ wants to force at first, then make sabaki in the corner

Leela Zero's preference (ctd)  

And then it unfolds like this.