Once A Year...

British Go Journal No. 62. July 1984. Page 13.

One of the more curious and whimsical positions that can arise is a triple ko. It usually occurs about once a year in professional games (less in amateur Go as the possibility goes unnoticed). Here is a good example between a youthful Kato Masao (Black) and Cho Chikun. The final semeai is both entertaining and instructive.

Black: Kato Masao
White: Cho Chikun
The game-file in SGF format.

Figure 1 (1-100) BGJ had Fig 1 as (1-78).

Figure 2 (101-156) BGJ had Fig 2 as (79-156). 143 at 127, 144 at 139, 145 ko at 131, 146 ko at 142, 148 ko at 134, 149 ko at 127, 150 at 108, 151 at 110, 152 ko at 142, 153 ko at 139, 155 ko at 127, 156 ko at 134.