My weekly Go study group usually meets in a meeting room off the main playing salon at the Kansai branch of the Nihon Ki-in in Osaka. However, because of a room scheduling conflict, for today’s class we were bumped upstairs to a part of the building I’d never seen before: the tournament rooms.

Housing eight Go boards (囲碁盤, igoban) as well as a large magnetic lecture-style Go board at the front of the room, the tournament room was far more intimate than the general meeting room we’d used before. Now I really want to come to this room to watch a tournament.

Each week we study four homework problems in a classroom setting, after which we review one of the games played by the students the previous week. (We record our games on kifu paper and give them to the sensei before leaving. He reviews them after class and selects one of them to show in class, based on what topics he wants to present.)

One of today’s problems really intrigued me. It wasn’t especially hard, but I guess I wasn’t thinking about the problem with an open mind, until one of my classmates walked me through the problem. It’s a question concerning the opening of a game. In the diagram (right), with black to play next, which of the four choices (A~D) is the best?

I felt certain that the answer would be “B” because of the importance I attached to protecting the side. After all, C looked to be barging into white’s territory without adequate support and A looked to be a standard approach move, but nothing extraordinary.

However, my problem was not thinking through the final option, D, from the point of view of the opposing color, white.  I saw the lower-left corner as exerting significant black influence toward the center of the board. However, as my classmate pointed out, if you imagine white at point D, you can quickly see how most of the black stones in the area could come quickly under severe attack by white.

The best answer is D. Live and learn.

My notes written just before the class (but after having realized the error of my thinking) read as follows:

一番強い選択はＤだろう。Ｄを選んだら、低いの左の隅が守られる。しかし、白いがＤに打つ場合に黒の隅に置いてある石は早く亡くなって来るかもしれない。